R1100gs 94 running rich

[Benjah]

Hi Guys

I've done a search on this but can't find the info I'm after.

The bike has no cat and has a CO2 pot. Just had it serviced an it was running fine.

On start up it puts out a fair bit of dark smoke that strongly of smells of gas. my mileage isn't so great either. the bike has 60k miles o it and i ride fairly conservatively.

Any ideas on how to approach this?

 

[Mac]

I wouldn't worry m8, mine does the same on start up but it clears pretty quick and runs like a dream otherwise

But then it's a 94 1100 with 60K on the clock.........

 

[Timolgra]

Check the TPS is working correctly.

 

[g.s.john]

check your plugs if they light brown and clean looking the mixture is probably ok,if they are black and sooty combine that with heavy fuel consumption the mixture is too rich it will also help if you get your air filter changed find your self a good mechanic because you are a bit far from me to have a look

 

[Wrigsby1]

GS's usually run at approx 45mpg or 10miles per litre under general "normal" riding. You can vary 5mpg either way for your riding style.

The plugs are usually nearly white with a hint of brown. As GS's are roughty tufty air cooled they can be sooty or blow a bit of oil smoke on start up but as long as this clears it should be OK.

If it has just been in for a BM service it should have had the CO pot checked or adjusted (when hot). The setting is 1.5% +/- .5% CO. If it's running rich it would probably be noticably sooty on the silencer end.

 

[MattW]

I worked out the fuel consumption of my 38,000 mile, '94 1100 several times over a just completed 900 mile trip around western Scotland. Two up with full panniers it varied between 53mpg (sustained 75mph ish motorway slogging) to 57 (mixed rural roads and twisties). So I guess I'm not running overly rich and yet my tailpipe is a bit sooty as is the inside face of the left hand pannier.

What gas mileage are you getting?

 

[Benjah]

Check the TPS is working correctly.

How do I do this?

check your plugs if they light brown and clean looking the mixture is probably ok,if they are black and sooty combine that with heavy fuel consumption the mixture is too rich it will also help if you get your air filter changed find your self a good mechanic because you are a bit far from me to have a look

Has a brand new airfilter.

I wouldn't worry m8, mine does the same on start up but it clears pretty quick and runs like a dream otherwise

But then it's a 94 1100 with 60K on the clock.........

Cheers to that. Maybe I'm been a too precious. Once it warms up it does run pretty sweet.

This forum rocks! You chaps are great

 

[dancata]

How do I do this?



Has a brand new airfilter.



Cheers to that. Maybe I'm been a too precious. Once it warms up it does run pretty sweet.

This forum rocks! You chaps are great

http://advwisdom.hogranch.com/Wisdom/tps3.1.pdf

 

[Benjah]

http://advwisdom.hogranch.com/Wisdom/tps3.1.pdf

Good gosh that's the mother link!

 

[Wrigsby1]

I worked out the fuel consumption of my 38,000 mile, '94 1100 several times over a just completed 900 mile trip around western Scotland. Two up with full panniers it varied between 53mpg (sustained 75mph ish motorway slogging) to 57 (mixed rural roads and twisties). So I guess I'm not running overly rich and yet my tailpipe is a bit sooty as is the inside face of the left hand pannier.

What gas mileage are you getting?

That's good mpg! My 96 GS is running a bit rough low down at the mo but is still in the 45/50 range. That's BM all over, all of them a bit different. I'm down on Cornwall in the middle of a 2k trip so will sort it once I'm home.

 

[Stewart H]

I have been suffering from poor fuel consumption on my 97 1100 for months, the final cure was to set the TPS at 0.36 volts, I reckon I must have booted it at some point .
Calculations on the ride up to GOTC resulted in mileage between 51 and 60 MPG !
I could not believe what the tank was taking, and just as well with fuel in the highlands going as high as £1.30 per litre.
Stewart

 

[Steve the Kiwi]

find your self a good mechanic because you are a bit far from me to have a look

aarr goo an.... if ever there was a good excuse to go for ride..... "darling I'm just going to help someone tune their bike....back in a "bit" "

 

[g.s.john]

aarr goo an.... if ever there was a good excuse to go for ride..... "darling I'm just going to help someone tune their bike....back in a "bit" "

look i know i bought the bike to ride but N.Z is a tad too far
anyhoo by the time i get there benjah will have got it sorted

 

[Benjah]

Latest update:

Have tried testing the TPS and couldn't get a stable reading. The voltage would vary between 4.1 and 3.3 ish. After flicking the throttle it would never come back to the same voltage twice in a row.

Sound normal?

 

[Stewart H]

Latest update:

Have tried testing the TPS and couldn't get a stable reading. The voltage would vary between 4.1 and 3.3 ish. After flicking the throttle it would never come back to the same voltage twice in a row.

Sound normal?

You may need to create some slack in the throttle cables to get a stable reading
Stewart

 

[Benjah]

You may need to create some slack in the throttle cables to get a stable reading
Stewart

Cheers. Any tips on how to do this?

 

[Stewart H]

Cheers. Any tips on how to do this?

Your bike is different to mine in some details here as you have the earlier arrangement throttle cable, in order to get a proper reading of your TPS voltage the throttles must be on their stops at idle, rather than being held open by the cable, it may be possible to introduce some slack by loosening the cable adjuster at the handlebar end, whatever you do do not touch the bolt/locknut throttle stops on the underside of the throttle bodies, these are factory preset and a bit of a bugger to get back if moved, but have a look at them to see that the throttle is fully closing when you check TPS volts, my own preference is for 0.36 volts at idle position, you might like to search for how to make a manometer to balance the TBs after messing with stuff here, note that the only adjustments to balance at idle should be the Big Brass Screws, then part throttle balance is adjusted by the cable slack adjusters.
Hope this helps

Stewart

 

[Steptoe]

Cheers. Any tips on how to do this?

I'm all for helping people, but if you don't know how to get some slack in your throttle cables i'd be leaving the TPS and CO pot adjusting well alone before you upset everything and you'll be chasing your own tail.

 

[Benjah]

well we all got to start somewhere I guess. I'm a nube bike mechanic by necessity I'm afraid as a recent final drive rebuild has eaten up my bike maintenance budget for quite some time. Plus I really enjoy finding out how it's all done.

I did make a manometer the other day and balanced the TBs as described on another thread. It worked brilliantly. Just an 1/8th of a turn on one side was all that it needed to really smooth things out.

Thanks for the tip on removing the slack. I'll check it out.

 

[Steptoe]

well we all got to start somewhere I guess. I'm a nube bike mechanic by necessity I'm afraid as a recent final drive rebuild has eaten up my bike maintenance budget for quite some time. Plus I really enjoy finding out how it's all done.

.

Then buying a workshop/haynes manual will soon pay for itself.