VX800 and a GS with a booster plug

botus

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So for last few months been tootling about on my VX800 with carbs. Interesting comparison re throttle response and behaviour... it pukes out the smell of wasted hydrocarbons like the worlds going to choke. And it feels so strangled with an air box that clearly doesn’t let any air through it ever and an exhaust so strangled it’s a wonder it starts... BUT the magic is the fuelling is perfect. It never holds back because it’s too lean, it never chugs because it’s too rich... it just works. I don’t understand how. You can smell the catastrophe and feel how strangled it is, but the throttle and the bike just work. There’s no hunting / chugging /struggling / complaining or questions about its competence. (Plenty wrong with the rest of the bike... like so little suspension travel even at 220kg of lead, it frequently takes to the sky at any opportunity.

And to the point of the post.... having got the GS out the contrast in joke fuelling is very stark. So I thought lets see if a booster plug I have doing nothing helps... And the answer is ODD, If adaptions are set to std does the cold condition map have to rebuilt its adoptions??? Coz it was horrible, but either I got used to it or it improved. But still quite wrong. So now as I have the power commander still wired but still in a Zero maps after the last software update and the CAT sensor still plugged in .... I'm thinking well with that plug on its far too rich at 3000 and still far too weak at 4500 ....

So IF the adoptions only work on closed loop for extended timeframe....

what happens is I take 3% off at 2% to 5% throttle at 2500 to 3500 (its massively better....) and now about right
and an extra 6% at 4500 at 80% to 100% throttle, (that better too, but not enough yet) and will this adapt out .... I hope not???
 
I rode another bike with Carbs and again can't get my head round how well they run down the bottom. So I've been making a more concerted effort to sort my GS out and I'm almost there even with the CAT sensors still connected.

Started with a stock bike that had the "new" map reflashed a second time (rather than the one mine had been running for 10 years) and had adaptions reset by the dealership, it settled back towards the std disaster a stock bike has.

1) lumpy idle
2) no bottom end power
3) unridable below 2600 rpm (the old map was unridable below 3500rpm)
4) snatchy response / prone to a cough in tight traffic manoeuvres just when you don't need it to
5) the rear bevel banging and clattering about trying to destroy itself in any condition other than constant acceleration
6) unbeknownst to you, you end up learning to ride around the recalcitrant bike holding gears you wouldn't, changing more often and generally riding in other rev ranges than it would need if it fueled right,

So after the smooth glitch free carb bikes, I put on a booster plug and went for a ride. Its different but a long way from correct. As the powercomander was still on with a zero map I decide to leave everything else on and add fuel as per first post. I got some wins but elsewhere it wasn't as smooth as I expected.... I realised dropping back from the booster plug enrichment in certain places was a big mistake. And now I've tweaked it more, 10 iterations later almost back to the good old days

I was beginning to think I imagined it was ever fun to ride.... I have been trying to be very conservative with the additional fuelling I was adding but that was my issue. Each time a little more allowed the engine to start operating where before it was unridable, but as you slowed to very low throttle settings trying to maintain slow but constant speed in traffic it was snatchy / surging / hunting ever so slightly (all the way from 1500 to 4500 rpm in various degrees. Adding another 1% here or there and each time it seems to improve... until today where I went for it, even with a booster plug in some places at 2% throttle I needed to add 11% more fuel on the powercomander…

and the end result the front wheel pops up in the air again at low revs, it blasts up the road and has a linear curve of real power from 1700 rpm to the red line in any throttle position. If I'm honest its the first time in 3 years its been running properly and the difference is startling
 
been getting irritated as at one throttle setting I can't get away from small glitches....

decided to review how other had set up old PC maps and see many at low RPM have a massive difference in fuelling between each cylinder.... Also realise the issues I had with others maps was probably related to the old BM map my bike had, depending on what your bike has, what the PC needs to do is almost exactly the opposite

Now I'm on the last map BM offered, I've given it a go like many others have and its far better in two areas I couldn't fix (2k rpm and 3k rpm at 2% throttle….)

Which begs the question...what were BMW doing if one cylinder needs 20% more fuel than the other one?
Is this literally emission fixing by deleting fuel off one cylinder till it reaches the limits !!! :bow
 
well.....

I'm beginning to line up with others who say booster plugs don't work. I'm also adamant that BM with the 2008 remap of the early GS1200 got it very wrong.

On a hot day the playing I refer to above sort of works (at times there a touch of genius going on) others there's this irritating surging on tiny throttle openings that's doing my head in. Then when the temperatures change the bikes a car crash (<15C).

That goes back to my puma case that they messed up the cold start fuelling. In 7 years never an issue... till that update went on then in the cold the bike's a hideous over rich mess. Chugging like it should be banned from the roads. It never ran funny before that update.

The bit that did my head in and convinced me to bin the booster plug was dropping back from shell 99 to BP 97 the change was huge.... from smooth refined and great in hot weather to rough, nasty and harsh on the BP stuff. So I've binned the booster plug, reset the adaptions and am starting again....

Oddly the midrange dip I'm almost getting to disappear.. Still playing with the power commander with everything connected up but have limited my self to adding a max of 2 and min of -2 in areas when I'm making adjustments (in the hope BMW's adaptions wont remove them…. Early days.

Another oddity is the rough chugging at 2k rpm. Its an anathema, I was playing with my brother there and he said he thought it was rich so, one cyl at a time I went from plus 20 to minus 20 and it didn't help. So then I went various settings any where between on one cyl and the opposite on the other and again it makes no real difference. Add 10% it chugs, remove back to standard it chugs, then drop to minus 10% it chugs, put 10% more on one pot than the other it chugs, swap that around it chugs... go 250 rpm either side of the 2000rpm chugging and its too lean :banghead::banghead::banghead:.

Had the gs 911 on it (no idea what I'm doing) and on one graph you can get the fuelling display on both pots jumping from lean to rich back and forth like a whore's draws, even at idle or around 2.5k rpm.... I didn't think it could control at those revs ????

Oh yes and this silly low throttle surging, is going on under the right conditions with the bike dead stock... so it that's another interesting addition I hadn't appreciated. The old map was far better... yes a bit of a disaster zone at low revs but magic everywhere else... and the old one could be fixed with a power commander, the approved current mess is just a special car crash
 
My 2010 twin cam,that had the controversial hilltop “tune”, has perfect fueling, though I think the decat Remus pipes have been the main reason for this.
 
I's like to hear more about the (Suzuki i hope) VX800.
Always been curious about them.
ANYhow .... carry on.
 
….I'm running the Suzuki on super unleaded. It seems smoother and happier.

Its an 805cc, v tiwn the right way round, like the best handling bike I've ever ridden a VT500. The clutch is rather grabby and you need to file back the lock stops to make it have some sort of degree of turn so you don't fall off after riding a GS. And its only got a 5 speed box.

It doesn't feel like its got a shaft and the bevel doesn't clonk and chatter round town like a BMW does. Power is "super flexible" you can just forget about gear changes. Its perfectly happy on the flat to change up at 2k RPM !!!!, if its a fairly big hill you have to raise the revs before you change up to 2300rpm, or its not quite happy but will do 2k on a hill in 4th !!!!!

it has no brakes whatsoever and basic suspension.... but its very relaxing. It makes you happy to go slow and see the scenery, whereas any BMW is only at its best when you go out with mentality of chasing down marquez to prove he can't ride.

https://www.cyclechaos.com/wiki/Suzuki_VX800#1991_VX800M
 
I decided I agree with my brother and his too rich theory at 2k. All along its does this chug like its overfuelling at these revs and its been there from new... but with a CAT and modern emission friendly electronics my head was telling me it must be weak (so I must add some more). And in places we all know it does get better when you add a bit everywhere else..... and as mistacat was saying you can way overfuel and it runs happy enough anyway.

So after I wrote post #4 I realised although I’d spent ages mucking about with fuelling at low throttle around 2k rpm I'd never tried going leaner.

Lets pretend its mechanically like new, the valve clearance are perfect and quiet. Now put in super unleaded, reset the adaptions, ride about till its going as well as it ever did in the 12 years I've had it (when in stock mode) using either the map it had when I bought it 12 years back, or the approved release from circa 2009 that went on 2 years back (and the rest of the bike is 100% stock BMW setup)…. Ensure the carbs are in perfect balance at idle and at 3k rpm, the stepper motor reset has been done and it still all in balance... and its just had 4 new coils (which if anything made it run worse)... BUT it must be OK as BMW had it back, checked it out, found nothing and reflashed it again FOC under the puma case I raised re they have no idea what they are doing on ecu Maps

Now if I sit at idle with a cold, warm or hot engine and just try to tease up the revs, its never been easy to modulate as the fuelling is such a joke. Its never had the ability to just go up the revs 100rpm at a time and hold a steady position for a few seconds. Then step by step go up 100rpm at a time get all the way to 4k. It just leaps from idle at 1200 to 1500 where you can hold it steady but it clearly running like a dog. You can't hold anything stable on the climb from there to 2k. With a lot of practice you can get a steady 2k but its chugging like an idiot, then a rough spot at 2200 where it hates life nearly as much at 2k... it then flies through 2300 to 2900, then complains again and this rubbish is more or less there in various degrees of incompetence till its over 3500 rpm and always was.

But on the original Map you could fix that with a power commander and on the later map you can’t. Plus we must remember they robbed 15bhp at 4500 on the later disaster Map and won’t drop back to the better one it had when they sold it.

Anyway back to the bike’s like new but the engine map is a BMW bog std car crash....So attach the power comander but leave the CAT sensors attached and based on 6 years of tweaking and learning …. as I mentioned in a post above, trying to limit any modification to 2 out of the 20 (in either direction) richer or weaker set points the PC3 has in the hope it doesn’t just adapt out again. On my 4th revision in this latest way of trying things I'm still striding onwards, better than BM manage (not difficult)... And for the first time ever I can almost play the 100 rpm increment game

Set off about 18:00 last night (without that stupid booster plug) in the cold 14C and it wasn't bad. Whilst this new set up seems to have got away from the shocking cold / warm weather contrast when running the booster plug, its not right for the first mile starting from cold, where conversely BMWs fuelling in that first mile that was right on the original map and always wrong on the current release and its clearly not as good as my ideas (with the booster plug). But soon enough its warm enough to have got over that and its clear my bodging is still an improving trend.

Though I could still feel the 3k hesitation on almost closed throttle irritating me (but almost gone) and the 2 k leaning out experiment, still isn’t enough. Both pots were on -2 of whatever units power commander use (I think 10 clicks on theirs is less than moving a notch on a needle - but the good bit is that’s a needle position for those revs & that throttle setting). So I went on a 2 mile detour to get the lap top and made more changes. Going to -3 at 2k and tweaking the 3k bit too. Did about 6 miles and decided leaning out that bit is definitely going the right direction. So time to stop and play the 100 rmp game... still improving, but the heavy chugging at 2k is still there big time.

So I went radical and did -8 on both and the chugging’s the same???... went to -12 on both and there an indication I’m finally headed in the right direction and now realise 2200rpm has the same overfuelling disaster. So wound that to -8 too and its better . But surely thats getting silly ? seems not ! went to -16 on each at 2k and -8 at 2.2k and struggled to see major gains whilst stationary, it might still be going the right way, but decided no way it would cope when riding and left -8 at 2k each side and stuck to -8 at 2.2k too.... BMW can’t be more incompetent than that can they !!!

Did another 5 miles with a lot of slow speed, low throttle playing and the thing is way better than BMW manage.... no coughs splutters or silliness. Not even a hint it would catch me out and by now it was getting down to 12C ambient. Pretty sure any rider would prefer my set up. Did the 100 rpm game again and still going the right way both riding or stationary but noticed 1500 rpm needs sorting too (but not sure richer or leaner, seems too rich are they really that thick ???)

It was quiet on the roads and I thought nothing ventured. Stuck the laptop on and went even leaner still left 2k at -8 each and went to -17 at 2200 , thinking well if it going to play up round town that should do it.... And ? its better still, and still no funny business just better than BMW manage, smoother, more consistent, better on / off a closed throttle, easier to modulate, less jerks, wobbles and incompetence. Then I remembered I forgotten to try anything at 1500 rpm and thought its getting dark the road are still covered in gravel from the rain weeks back and I’ll come to it fresh another day and see if it’s still any good..... then played the 100rpm game as I parked up and it’s still chugging at 2k WTF were BMW doing
 
Ta for the reply. :thumb2
…. its very relaxing. It makes you happy to go slow and see the scenery, whereas any BMW is only at its best when you go out with mentality of chasing down marquez to prove he can't ride....
I'd love to have a go on one to see if expectation meets the reality.
 
so on sunday the fun starts again.... made more tiny tweaks based on all I'd been through before....

but leaned it off more and it was great from cold start, playing whilst stationary, then it got hot and bothered and played up and I bottled the settings going to to -9% at 2 and 2.2k rpm on 2% and -7% an -5% on the right pot.... and it was awful, ran round the house making gains here and their but worse in others... got worn out trying, began to wonder if it was adapting out everything I was doing

as a last resort went back to the crazy settings from last night and it was incredible, instantly smooth, crispy, fast, stable - everything I hadn't managed on 5 versions of tweaks earlier in the day
 
another run today.... it almost behaves like BMW had done what they were supposed too. And by making it leaner !!!
 
I typed this up for a Merc forum so they get why the dieselgate fix they are pushing out to cars now, needs the owners to expect a difference as their cars rebuild adaptions....

My BM bike has been a car crash for 3 years after a software update. I was trying to tune it (with a power commander thing that worked well with the old map) but couldn't get anywhere.... Eventually went back they reflashed and this time correctly wiped the adaptions and its a totally different vehicle. But still wrong...

After the last dealer visit I rode about to warm it up and the thing was horrendous, much worse. It wouldn't run right and once warm it wouldn't rev past 6500 (red line's at 8000). I couldn't believe it. I had actually turned round and was on my way back to the garage to say WTF... when I decided stuff it I'm just going to put in a low gear and try to get it to rev out.... over then next 2 miles it improved and then suddenly picked up and ran right. I couldn't believe what was happening. Then I realised it could only be the adaptions adapting (but I'd never experienced it before, and no one had ever told me it can be this dramatic). A bit more thrashing and it was making proper power after 7500 rpm in ways it hadn't for 18 months. Top end that was just gone was suddenly back and it revved out like the bike did in the 7 years before it had been updated. And a mid range hole was now 1000 rpm smaller affecting only a 500 rpm rev band rather than the 1500 rpm one it had since the updated map went on. But it was still there.

The next step change was months later.... the GS (the one they ruined with an engine map update) was never supposed to run anything but 95 and on the old map it ran exactly the same. Another ride out and I still wasn't making headway after yet another tweak to fuelling on the power commander. Realising I was going in circles I was puzzling why BMW would not put the original map back on under an special puma case I raised. (its a special escalation they don't want you to know about - where a customer complaint the software is crap, gets investigated thoroughly). So I was going through my mind what's wrong, and what you need to do to sort their stupid later map, when I realised I was low on fuel. I was in a strange part of High Wycombe where there's two garages that are always cheap and one was Shell... And I suddenly remembered I'd never tried Shell 99 super unleaded on the later map on this bike !

The knowledge that 97 did nothing but 99 does came a year into owning another BM bike. This one was supposed to run higher octane stuff but would never behave any different when you filled it up with the expensive stuff. Then it was utterly transformed when I switched brands. Esso and BP super unleaded is only 97 and it does nothing, but Shell is 99 and within 15 seconds of starting after a full tank of Shell super unleaded the bike was utterly different. With huge unbelievable gains. Literally it was transformed before I got off the garage forecourt. Noise, smoothness, flexibility and performance gains were massive. So much so you'd believe you were on a different bike.

So 9 months after BMW reset the adaptions I got to try 99 octane in the GS and again there was an instant impact straight way. The flat spot hadn't gone, but again it was a huge leap towards where it had once been (on the old map).

Now with a bit more vigour and a new tool I decided to keep trying and set up the power commander to make certain points leaner which seems to help !!!... and as I'm sure much of the problem is related to one of the fixes in the newer map - which was "improved sensitivity of the knock sensors" - its causing it to wind back the ignition where it shouldn't. Then reading about getting other brands to re adapt well. I discover its supposed to be done gently, over a few hundred miles. Knowing the last ground work setting up its adaptions was done in a rush on 95. I wiped the adaptions and have been rebuilding gently with 99 octane and suddenly the hole is gone... its only taken three years of trying !!!

One main dealer kept saying the only thing he could think of, was to "put it to std and see where you are..." which I think was code for reset the adaptions... All a lot easier when someone explained why and you have the tool to do it
 
...the comment about the hole having gone... is exactly that.

Its still nothing like as good as the original map, but after 3 years trying and now running shell 99 with rebuild adaptions and the PC3 taking fuel out on some rpm bands at low throttle conditions and adding fractional amount elsewhere its NOW far better than its been. Sadly mostly flat across the 4.4 to 5k dead spot they built into the later map but now manages to get past it as if you're on 75% throttle, far better than the yawning chasm its been for 3 years. It almost as if they thought to build anti wheelie and traction control in to a stock engine map without using any sensor data to know if it needs to be wound back!!!

As is now I'm actually getting air after 5k in third and forth (something its never done in the 12 years beforehand on a flat bump less road). The original map with the hideous errors removed (using a PC3) would get air from 3k on anything over 50% throttle and be workable based on throttle input holding air past 6k in low gears till it ran out of go. But it couldn't create air just banging it on full throttle after 5k. And contrastly, when you are caught up in traffic I'm now running up to two gears higher.... I can ride it down to 1500rpm in top and it runs correctly and makes power and is able to accelerate out cleaning

Where I've managed to get it now, I can get lively air from as little as 2.5k, drops down around 4 but continues to accelerate (which is nice after its 3 year holiday) and now air comes back at 5500rpm (just). Now I know the air is pointless and mostly a nuisance... but the ability of the bike to make some power and start to do what I want using the throttle grip is exceptionally helpful if you want to ride properly.
 
I was out again yesterday, two main thoughts...

1) booster plugs are a mistake. Its far more consentient between temperatures. Its quite steady between cold or warm ambient conditions without it. The booster plug just made it haphazard
2) its perkiness down the bottom is hugely different since I went lean at 2k and 2.25k, reset the adaptions and its been readapting using 99 octane.

I'm needing to re calibrate my thottle hand as the fronts popping up all over the place at low rpm like it hasn't reliably for 3 years. The flat bit 4.4 to 5k rpm is pathetic, why BWM ruined the bike I don't know, after 5 it takes off, possibly going through 6k quicker than it ever did. And it does get air where it never did before, so something about where it is now is making power and torque after 5k in ways it has never done before. But top end isn't what it was. Its pulling really hard from 5 to 7.4k but then its tailing off fairly quickly after that. It used to pull hard in to the rev limiter on the old map and was doing better before I last reset adaptions about 80 miles ago - maybe its still finding its feet up the top?

I got one odd moment where it had a cough just after I gave it a fist full going up on to a steep hill from 2.5 k rpm and 80% throttle, as it hit something over 3 k pulling hard got one massive cough then carried on. Tried to replicate and got nothing odd over the next 10 miles.

At one point I was trundling along and the bevel started to chatter a bit... I thought that's odd. Its been dead smooth just before what's going on. Looked down and I realised I was down to 1200 rpm in 6th. Just before that it was quite happy doing just 1 or 2 mph faster for the last half mile, which as I keep suggesting BM have no idea what they are doing re fuelling
 
my other brother has been ranting about injection lately and thinks the world was better on carbs...

I tell you wot having found it a nightmare to get things to going the right way with a laptop, I'm kind of in awe how the old boys did such a good job on carbs.... how long did it take them???
 
my other brother has been ranting about injection lately and thinks the world was better on carbs...

I tell you wot having found it a nightmare to get things to going the right way with a laptop, I'm kind of in awe how the old boys did such a good job on carbs.... how long did it take them???

It took forever and they were still not right.
Many years of racing V8`s without proper diagnostic kit it was more plug reading and guess work.
On my current V8 (road engine) I fitted a new 4 barrel Edelbrock carb and performer manifold which I thought that I had jetted spot on, I then welded a couple of lambda sensor bungs into the headers and fitted a throttle position sensor, to hook up the Innovate dual channel LM2 to. Then set up the mixture properly not far out before but not right.
I wish this affordable kit had been available many years ago.
By comparison I have set my airhead (Bings) up with the Innovate LM2 and whilst the AFR is as good as it can be the graphs are not as good ( fueling cylinder to cylinder) as my 1200gs TC with AF-Xied`s fitted.
Carbs were easy to mess about with but to get exact fueling they do not come close to injection.
I have played with power commanders 3 & 5 and the autotune but day to day I could not get stable consistent fueling.
The AF-Xied`s are fit and forget.
 
but the issue with the dead midrange is 100% ignition, they even admit that messed it about ….

there is nothing really wrong with the fuelling at this point. And I've made no real progress in 3 years playing with fueling there on the later map. The really frustrating point it was never an issue on the old map, the tiny dip you had then, all you did was added +10 on the PC3 from 60 % throttle or more at 4500, 4750 and 5000 rpm on a PCs and it was totally gone...

they clearly felt the need to wind back the ignition for some pointless annoyance.... so AF-Xied will add no value. I can believe on the old Map they'd be absolutely brilliant and if I could get here without throwing 100 quid at two governments, I'd be happy to try but it won't bring back my dead midrange
 
Botus,

I read about 2/3 of the way through this and have a question and a couple comments.

My question is, what is a BM remap, and do you still have a non-standard map installed?

I believe I’ve read that you have a Power Commander (without auto tune) and that your stock narrowband sensors are installed and connected.

If the above is true, any fuel you add below 50-70% fuel (I forget exactly where open loop fueling starts) will:

1. Become completely removed below 50-70% throttle by the long term trims (adaptations), as will any effect from a booster plug anywhere.

2. Any added fuel below 50-70% throttle will reduce fueling above 50-70% throttle AND any reduced fueling below 50-70% will add richness above that range. This happens by the long term trims. How strong this reverse effect is depends on how close the additions are to the top limits for closed loop.

If you’re messing around with a PC, you should disconnect the O2 sensors and reset adaptations in the ECU. Or even better, leave the O2 connected, remove the PC, ride for a week to build good adaptations—then disconnect the O2s, install the PC and don’t reset the adaptations.

From your description of the symptoms I’d send my injectors out for cleaning and testing before doing anything. Make sure they’re reasonably well matched and have a good spray pattern.

We get the hexheads and camheads to run very well with only the addition of either LC-2s or AF-XIEDs.
 


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