Any ideas? Related to the question of course!

[Canuck]

Location: Outside Exeter

Bike: 04 GSA with 19000 miles.

Parts: Cat + Remus exhaust (+ extender pipe to keep heat off panniers)

Problem: Bike pulls hard up to 5000RPM. At this point the power seems to die. Now when I'm "givin' it some" I would shift around here anyway. When I do shift however, the engine takes about 1.5 - 2 seconds to pull again.

My thought: Needs a new fuel filter (?) Fuel/air ratio running a bit rich (?) Going to make a manometer when I get a chance and adjust valves and balance throttle bodies. Would cleaning the lamda probe help (and how the heck do I get to it?).

Question: Anybody have any ideas as to what to try first or what may be causing the problem. I'm going to head out now to see if I accelerate slowly up to 5000rpm, if I am still faced with the issue of power loss. Advice or tips greatly apprciated.


Apart from this she runs really well and I am enjoying my newly acquired toy ... err... mode of transport!

 

[Canuck]

update...

So after some very scientific testing, I have deduced that under 'normal' acceleration everything is fine. It is only under hard acceleration that the issue occurs. My guess is fuel filter...??? Any other thoughts or am I on target?

 

[Bikerbrady]

my 2004 r1150gsa started doing same at 20k.................coils,changed em and ran like a dream again

Biker

 

[Colban]

BWM say change fuel filter every 24K.With the good UK fuel,they normally last a lot longer,unless you've got water in it.
Can you hear the pump whirring at all?.
My money is also on a failing coil stick.

 

[Pukmeister]

So is mine.

 

[Canuck]

noises

I definately hear the fuel pump... Is that is good thing or a bad thing?

My big "Jonny Depp look-a-like" buddy was worried his pump was problematic until he heard mine, which sounded the same. Does this mean both our bikes have problems or both are normal?

I usually don't worry about things until I break them but the missus and I are hoping to take a trip around France in 5 weeks and I would like to get back on the same bike I left with!

 

[Canuck]

update2

Just did the search for stick coils... Top tip guy! I'll order two and see what happens. Still looking forward to the valve adjustment and throttle bodies!

The last engine I played with was my lawn mower back at my parents house when I was about 15. I managed to get it to do wheelies... until I completely knackered it which happened soon after I discovered my wheelie abilities.

And anyone who tells you lawn mowers are not made for off-roading lies... put on some decent tires and viola... take the path less chosen and cut your own path!

Thanks guys!

 

[Steptoe]

Just did the search for stick coils... Top tip guy! I'll order two and see what happens.

Possibly save yourself a £110, pull the lower plugs off and see if it runs on the main plugs. If it does it's not them.

Connect one lower side at a time to check if only one has failed.

 

[Colban]

I definately hear the fuel pump... Is that is good thing or a bad thing?

If you can hear the pump (apart from when it primes at ignition ON),i believe it usually means its struggling.Low fuel,blocked filter etc.
If your pal has got the twinspark motor,borrow his coils to see if it cures it.

 

[Canuck]

update 2

I pulled off the lower wires and bike still started fine. Will be doing the valves and throttle bodies this weekend to see if that sorts it out. The coils look like new to be honest.

After valves I'll have a go at changing the fuel filter... sounds like a fun job!

 

[Canuck]

Okay incase anyone else has a similar issue thought I would post what happened.

As I didn't believe the coil sticks to be a problem I decided to adjust the rocker and valves. The left side was spot on min. clearance so I left it... had a good peek in there though and I'll now add an oil change to the list of things to do.

The right side however, I couldn't get the feeler in so I adjusted the valves accordingly. Only the intake size was too small as the exhause ones felt fine (after I adjusted the intake) The rocker was only slightly wider (I could squeeze in the next size guage) so I left that until I re-check them all in 6 months.

Put everything back together, started it up and voila! No more 'sluggishness'
at 5000rpm and.... the bike now roars like a lion and goes like the stink!

Very please and with steptoes 'guide to valvetry' took about one hour (it was the first time I had ever looked in an engine).

Checked the throttle bodies and everything was beautifully spot on.

Going to check rear bearing and FD as the bike is only getting 250-260 miles on a tank, and the rear wheel is making a vibe feel every now and then. It's also a bugger to turn by hand so worth a check for the price of a new seal and ties.

Thanks for the tips!

 

[MattW]

Good job

Just goes to show how important valve fettling is on our bikes.

 

[Number 6]

Just how tight were the intake valves? Unless it wasn't actually closing it wouldn't affect the running as bad as you described.

When you did the valves you took off the ht leads and then replaced them and your fault was 'cured'. I think that is where your problem is/was.

 

[Canuck]

Just how tight were the intake valves? Unless it wasn't actually closing it wouldn't affect the running as bad as you described.

When you did the valves you took off the ht leads and then replaced them and your fault was 'cured'. I think that is where your problem is/was.

Well they were too tight for the min. allowance feller guage to fit in. I didnt actually try anything smaller... didn't see the point really. I figure if it wasn't allowing enough air in then I wasn't getting as much power as I should of been as there would be a reduced amount of oxygen... once adjusted the result would be a better combustion and less unspent fuel in the intial spark.

And I didn't replace the HT leads...

 

[illustratedman]

going to check rear bearing and FD as the bike is only getting 250-260 miles on a tank, and the rear wheel is making a vibe feel every now and then. It's also a bugger to turn by hand so worth a check for the price of a new seal and ties.
Thanks for the tips!

250-260 is about right till the petrol light comes on, the vibey fell is likely to be the rear tyre, had the same feeling from mine changed the bearing etc no joy, changed the tyre problem solved, a few others have had it as well. They arent that easy to turn by hand.

 

[littleredrooster]

Well they were too tight for the min. allowance feller guage to fit in. I didnt actually try anything smaller... didn't see the point really. I figure if it wasn't allowing enough air in then I wasn't getting as much power as I should of been as there would be a reduced amount of oxygen... once adjusted the result would be a better combustion and less unspent fuel in the intial spark.

And I didn't replace the HT leads...

If the clearance was too small, the valve is actually opening more than it should, not less. Valve lift has very little effect on gas flow once it is clear of the valve seat; diameter is the main criterion, so it doesn't actually work like you may think. I like the joined-up thinking, though!
Not sure what you might have done to cure it, but my starting point would have been to check the TPS setting; you need about 380-400 mV to make the engine run sweet.

 

[Number 6]

And I didn't replace the HT leads...

Replaced as in you put them back. (perhaps refitted would be a better word) I didn't mean that you had fitted different ones

 

[Canuck]

If the clearance was too small, the valve is actually opening more than it should, not less. Valve lift has very little effect on gas flow once it is clear of the valve seat; diameter is the main criterion, so it doesn't actually work like you may think. I like the joined-up thinking, though!
Not sure what you might have done to cure it, but my starting point would have been to check the TPS setting; you need about 380-400 mV to make the engine run sweet.

Interesting... although do you realise the problem you have just created? I hate not knowing things so now instead of reading what I should be reading I'm going to be reading about internal combustion engines... I should try and dig out that project I did when I was 9... hmmm... I wonder where that is...

Replaced as in you put them back. (perhaps refitted would be a better word) I didn't mean that you had fitted different ones

Ah yes, makes sense now.

Please let me think I fixed something by wrenching otherwise you will have ruined my week! I'm sure it was the valves...

 

[Canuck]

Not sure what you might have done to cure it, but my starting point would have been to check the TPS setting; you need about 380-400 mV to make the engine run sweet.

TPS was spot on... checked that as well. Once again I was a bit annoyed that I didn't get to fiddle with anything but was also happy that things were as they should be!

 

[rogerc]

I think you are correct with the valve clearance issue. If the cold clearance is too small, then the rocker will not allow the valve to close fully once working temp is reached.....also resulting in burning of the valve seats. I was always taught the clearances are always better slightly higher than lower.....although lower clearances result in a quieter sounding engine.....not always a good thing.