GS 1100 running richer than oprah.

[alphadog]

so i bought a 75th anniverary model off this forum a few weeks ago. very happy with the purchase ,however the bike was running really rough at idle and only smoothed out when it hit about 3 thousand mark. i have synced the throttle bodies at 3000rpm and tried my best to set idling at around 1200rpm.
but i noticed that the air screws are way out of sync when i set idling, one is 1 turn out and the other is about 2 turns out. at this setting the throttle bodies are still synced at 3000rpm. i did this today after filling up and discovering that the 110 miles i have done took 17litres of fuel !! about 10km per litre. i have owned one of these before so i know i should be using nearly half that. the bike has stood for about 2 years, it has been looked after and one throttle body has been done /serviced to repair a rattle. also i noticed that the left hand air screw was fully wound in. any help with fuel consumption issues would help.should ad the bike has a aftermarket pipe so no cat and no lamba sensor on pipe.

 

[mikeyboy]

Does it have the “bridging “ connection fitted in the cat coding plug?

 

[DrFarkoff]

Start with basics

Make sure rubber caps are on vac points

Slacken off both cables to throttle butterflies so that you have 2mm of free play before they start to turn the cable quadrant

Turn the BBS out about 2 turns

Check the TPS you want about "point 4" of a volt with the fast idle off

Get it warmed up and then check the balance

Sync the throttle balance off the cable adjusters so they are very close when you twist the grip BUT leave a mm of slack!!

You want idle (when at 5 bars after a 20 min ride to be 1050 rpm plus or minus 50 rpm)

Do the cable slack before the tps setting / check

I have had quite a few over the years where they have been kicked or heavily bumped and changed the voltage at the idle position

The tps @ 0.4 volts indicates to the ECU that it should inject the fuel volumes for idle running

Once that value gets kicked up the scale it injects more fuel but the air is still the Idle

So once it's up to temp and you get back

check cable sync and adjust the BBS to get that 1000 - 1100 rpm tickover when hot

Make sure rubber caps are on vac points

 

[alphadog]

thanks for the comments and what is interesting is the bridge comment as the bike had an open space where a relay or fuse should be with a loose wire hanging out on one end, i wondered what this was and did a lot of digging on the net, i ended up connecting the loose end to number 6 and havent ridden it yet, i am still not sure if it richens or leans the mix. i also did the whole balancing act again.

 

[alphadog]

This is what I have done.also what the heck is that key slot for ????

 

[DrFarkoff]

thanks for the comments and what is interesting is the bridge comment as the bike had an open space where a relay or fuse should be with a loose wire hanging out on one end, i wondered what this was and did a lot of digging on the net, i ended up connecting the loose end to number 6 and havent ridden it yet, i am still not sure if it richens or leans the mix. i also did the whole balancing act again.

Never mind that wire! Pull it out for now and leave it off the bike

You then have default base settings to work with!

Did you check the TPS value ?? if it is not correct it will be overfueling!

to explain at idle the value should be 0.38 volt (0.4 is good enough for 20 year old thing)

with that value it injects fuel for idle, But if that value @ idle is say 0.7 or 0.8 volts then it is way too rich as it is injecting mid rpm fuel with only the idle value of air as the butterflies are not opened for mid range rpm

Do you get where I am coming from

 

[alphadog]

Never mind that wire! Pull it out for now and leave it off the bike

You then have default base settings to work with!

Did you check the TPS value ?? if it is not correct it will be overfueling!

to explain at idle the value should be 0.38 volt (0.4 is good enough for 20 year old thing)

with that value it injects fuel for idle, But if that value @ idle is say 0.7 or 0.8 volts then it is way too rich as it is injecting mid rpm fuel with only the idle value of air as the butterflies are not opened for mid range rpm

Do you get where I am coming from

hi, no i havent checked the volt value as i was unsure how to do it while still on the bike and with the bike idling ,still more research to be done there. i have found with all the reading over the last few days the posts keep jumping between the tps and the co poteniometer at the back when talking about excessive fuel consumption, it was in these posts on various adventure riding sites that i came across the wire hack, [which had been tried i guess] i thought that it set it back to default as the original relay had been pulled out. i did do about 50 miles on the bike with the wire connected and there was no difference in the bike at all, will remove it tommorow.thanks for the advice.

 

[mikeyboy]

Interesting that the bridge wire wasn’t connected,
On my 1100 I removed the bridge ,the fuel consumption was horrendous.
It went well though

 

[DrFarkoff]

hi, no i havent checked the volt value as i was unsure how to do it while still on the bike and with the bike idling ,still more research to be done there. i have found with all the reading over the last few days the posts keep jumping between the tps and the co poteniometer at the back when talking about excessive fuel consumption, it was in these posts on various adventure riding sites that i came across the wire hack, [which had been tried i guess] i thought that it set it back to default as the original relay had been pulled out. i did do about 50 miles on the bike with the wire connected and there was no difference in the bike at all, will remove it tommorow.thanks for the advice.

Carefully pull down the rubber boot at the TPS

You need a half decent Multimeter and it helps to have the crocodile clip ends on it

Pull down the boot and slide a paperclip up into the rearmost connector port and try and make a good contact

Now connect the positive wire to that paper clip and the multimeter ground wire to the battery earth or a really good earth

Switch on the the multimeter to 20V DC

Switch on the ignition

Without touching the throttle you want to see 0.38 ~ 0.4 volts

If you are seeing more or less volts slacken the two small bolts securing the TPS and move it just a millemeter at a time and keep checking to see what way the value is changing

Nip up the two wee bolts and see if the value changes when they are tightened If it does slacken and readjust until you get the value you need

Twist the throttle grip a couple of times and see what value you have ? If it is in the ballpark let it slide and tighten the two wee bolts and go for a ride and see how it pulls and if your pipe is still sooty

 

[alphadog]

hi, thanks very much for taking time out to write that down Dr, very much appreciated..will get on to that this afternoon [sunday]

 

[alphadog]

So when I checked the volts it was point 9......so I have managed to set it at point 387 closest to 4 I could get. I then got the throttle bodies set at 3000rpm spot on.however I could not get the throttle bodies to sync at idle.
so I set the idling using the big screws and went for a quick ride .it pulls great but it seems a bit lumpy on idle and the potentiometer is now cock eyed on the screws as before it was level.does this matter at all.
i also noticed that the right cyclinder is running much hotter than the left, no idea if this is a new development on my part or it was always like this as i happened to have a heat gun close by.

 

[DrFarkoff]

Did you make sure and leave free play on the cables ?? Throttle is not Hanging on them?

The Lumpy idle and the right side running hotter than left would indicate that the cable is not set back into its rest position correctly! Make sure that the throttle quadrants are returning all the way to their stops with a click when you release the throttle quickly

Re the TPS What matters in the voltage reading BUT worth checking the readings against something of a known value for a reference Or an expensive meter (basically a calibration comparison!)

 

[ELIMINATOR]

Probably irrelevant

Years ago I tried balancing the throttle bodies without success, took it to Steptoe. He found that a large piece of grit was stopping one of the throttles closing, it was caught in the drum.

 

[alphadog]

so today i loosened all the cables and started from scratch again, everything appears to open and close in the right places and the stops are both getting hit, balanced on the cables at 3000rpm but still wouldnt balance on idle, i changed the o rings on the intake manifold thinking it may be leaking there but made no difference, it idles but right hand cylinder still way hotter, about 60 degrees hotter. i took the plugs out after a short ride and was amazed to see that they were both burning the same, i would have thought that the right cyclinder would be much leaner, even though it wasnt a proper flat out plug check.
going to walk away for a day or two to gather my thoughts and do more research. this has me stumped at the moment.
maybe have a quick look to see if there is any grit laying around.

 

[ELIMINATOR]

60 degrees! What are the temperatures? Is it the case of one being too hot, or, the other is too cold.

Just to make it clear, are you talking Fahrenheit or Centigrade?

Must be the former, ?

Cant remember what temperature my rocker covers are, but, they're within 5c of each other, and I can touch them without getting burnt, unlike my Guzzi.
Slipped when standing up, bare forearm on the top of the rocker box.
The opening scene of "Kung Fu" flashed through my head, where he picks up the hot cauldron, emblazoned with a dragon logo which left scars.

Fortunately I didnt get to sport a MOTO GUZZI logo on my arm.

 

[DrFarkoff]

so today i loosened all the cables and started from scratch again, everything appears to open and close in the right places and the stops are both getting hit, balanced on the cables at 3000rpm but still wouldnt balance on idle, i changed the o rings on the intake manifold thinking it may be leaking there but made no difference, it idles but right hand cylinder still way hotter, about 60 degrees hotter. i took the plugs out after a short ride and was amazed to see that they were both burning the same, i would have thought that the right cyclinder would be much leaner, even though it wasnt a proper flat out plug check.
going to walk away for a day or two to gather my thoughts and do more research. this has me stumped at the moment.
maybe have a quick look to see if there is any grit laying around.

Good work there!

it's just a matter of tweaking a few things usually with these machines

Did you do a valve clearance or a compression test on the engine yet

Possibly a tight valve clearance or a cracked valve, a Comp test will confirm a direction that you can look further into

 

[alphadog]

valve clearance fine but havent been able to do a compression test yet as i dont have the tool, but will ask about for one.

 

[alphadog]

60 degrees! What are the temperatures? Is it the case of one being too hot, or, the other is too cold.

Just to make it clear, are you talking Fahrenheit or Centigrade?

Must be the former, ?

Cant remember what temperature my rocker covers are, but, they're within 5c of each other, and I can touch them without getting burnt, unlike my Guzzi.
Slipped when standing up, bare forearm on the top of the rocker box.
The opening scene of "Kung Fu" flashed through my head, where he picks up the hot cauldron, emblazoned with a dragon logo which left scars.

Fortunately I didnt get to sport a MOTO GUZZI logo on my arm.

it was centigrade.

 

[DrFarkoff]

valve clearance fine but havent been able to do a compression test yet as i dont have the tool, but will ask about for one.

Do you do your valve clearances with a 2 sets of feeler blades under each pair of inlets and pair of exhaust rockers in turn??

Gunsons one works fine for compression tests M14 plug thread if I recall correctly

Edit? Sweet Jaysis when did they become that price???

 

[alphadog]

Do you do your valve clearances with a 2 sets of feeler blades under each pair of inlets and pair of exhaust rockers in turn??

Gunsons one works fine for compression tests M14 plug thread if I recall correctly

Edit? Sweet Jaysis when did they become that price???

one old feeler gauge, cant believe it would make a noticeable difference ? i have seen those "sets" with the little tabs used on the youtube vids but didnt think it was mandatory. how would it better the outcome ?

edit..... just seen the advert for the feeler blades at moto works along with the explanation of why to use them, every day is a school day.