Gsx1100 Won't idle lower than 1500rpm

[Spiff]

2024 edit: solution in post #13.

Assuming my tacho is correct , My gsx1100 engine won't idle below 1500rpm. If I try to set it lower it'll just run for a few seconds before it leans out and dies. (observed with a wideband o2 sensor)

There's no issues with the idle as long as I set it a bit higher, will happily idle at around 1500 all day long. But not at 1000-1100 as I would like it to be.

Engine is a stock 82 gsx1100 with a hindle 4221 exhaust, K&N airfilters and dynojet stage 3 kit. I have gone up one size on the pilot jets but I'm still at 3.5 almost 4 turns out on the pilot jet screws so I have ordered the two next sizes up and I'm waiting for those.

Any input on what to try or should I not bother anymore with it?

Carbs are clean, synced, and no air leaks that I can find.
​

 

[Rob S.]

I, too have an '82 1100E with exhaust, pods and Dynojet. While mine purrs beautifully at 1k, I had a slightly higher mileage Z1 that would not idle at 900 rpm; apparently it had never read it's own owner's manual.

I think 12 was the lowest I ever got her to idle nicely, but it might have been closer to 15. I just chalked it up to her age, and we both lived happily ever after. :stupid:

 

[gustovh]

I run pods and a supertrap on my 80 1100L as well as a stage one kit. Went up on the mains with the jets provided in the kit, needles at the 4th slot from the bottom. A good sync may cure your problem.

V

 

[Spiff]

I use the stage 3 main jets but the pilots are too lean.
I've synced the carbs but it still won't idle lower

 

[gustovh]

take a look at my stymied thread...just a thought.

V

 

[Spiff]

take a look at my stymied thread...just a thought.

V

Thanks. I'll be sure to check those plugs when I get my o ring kit

 

[chuck hahn]

Is the cable adjusted properly. Should be a little slack in it. If no slack loosen the jam nuts at the carbs and adjust

 

[Spiff]

Is the cable adjusted properly. Should be a little slack in it. If no slack loosen the jam nuts at the carbs and adjust

Yup. I've checked that ass well

 

[Nessism]

Maybe check cam timing? Make sure your ignition advance unit is moving smoothly?

Typically, there is no reason to increase pilot jet size. Maybe the idle is rich, not lean like you suspect? Lastly, it's not a common issue, but you could be drawing false air past the throttle shaft seals.

 

[Spiff]

Maybe check cam timing? Make sure your ignition advance unit is moving smoothly?

Typically, there is no reason to increase pilot jet size. Maybe the idle is rich, not lean like you suspect? Lastly, it's not a common issue, but you could be drawing false air past the throttle shaft seals.

Not uncommon to increase pilot jet as well as main jet when doing pods and exhaust.
The idle right now is about 0.9 lambda, so just on the rich side, but as soon as you start to move, riding at about 1/8-1/4 throttle it runs lean. And seeing how far out I need to set the mix screws just to get it to idle decent it's obvious the idle jets are to small.
Cam aren't adjustable are they? I've checked valve clearances several times and didn't see anything out of sync when setting the cams for this procedure. Advance unit is also working as I see the timing marks move when revving it.

 

[Nessism]

Did you try lifting the needle?

 

[Spiff]

Did you try lifting the needle?

I've played around with needle position yes. But it doesn't explain why my idle is so high.

 

[Spiff]

Bringing this back from the dead to give you guys the answer and solution. Finally! I'm well chuffed by this!
So it turns out it's my own damn fault... Probably while assembling the top end the crank must have moved a tooth or two. This in turn lead to really low compression which screwed every thing up. I got it set up right and now my cold starting problems are gone, it idles stable and the power. My god the power. How many horses was omitted by the 60psi loss of compression?! IDK but quite a few I guess

Would still be chasing my tail had I not done a compression test, and I probably would have tore down the motor had it not been for the fact that I changed piston rings and lapped the valves before it was assembled so didn't buy the piston rings, leaking valves solution. Anyways. Thought id update in case someone in the future needs the info

 

[Spiff]

Nessism nailed it.

Indeed he did. Just to bad I misunderstood what he meant with timing