any risk for a overly RICH idle?

[mikeh]

I hope I dont come off as this being a dumb question, but other then fouling the plug, is there any risk to engine damage for having a overly rich idle circuit? i know my idle is too rich, pretty sure its the pilot. cuts off sometimes at lights when I roll the throttle, I think I have a 33 pilot jet, and I think its just a bit much. its a 47mm BBK with intake filter. it will start up and idle, i do have it set kind of high, and as such i around about 2100 on idle. no CVT engagement. It will stall out at lights, which presents another safety issue, but I have just been goosing the throttle.  Ive looked at a bunch of carb tuning video on the Tube and im PRETTY sure its just a too rich pilot,, it does fine from 25% throttle to WOT.  

what are the chances its the otherway and actually LEAN? i turned the fuel/air mix screw in 1 1/2 turns and it really, really hated it. 

I guess i am several turns out counterclockwise.  I have attempted to run it around and tune post warm up but im basically in the same spot. I dont think a plug chop would help me figure this out.



I dont have the money right this second to order new pilot jets (even though they are pretty cheap on amazon) and  I just wanted to make sure I wouldn't do any lasting engine damage.  bike runs great otherwise, does 40-43 mph in the mid 8000's.  Kinda stuck riding it as is, for work. 5 miles or so one way. 

any thoughts or ideas would be appreciated!

-Mike

[SMALL CC TEK]

Mike , other than killing your fuel mileage and killing your oil way be for it should. Your not doing any lasting damage at all
i have seen guys run them so rich a black puff comes out the exhaust with every movement of the throttle yet they run for a year like that ! lol question: did you look at your float adjustment? Did you adjust that at all or check it ? That could cause a rich issue also ..

[mikeh]

Dec 1, 2019 17:23:55 GMT -5 SMALL CC TEK said:

Mike , other than killing your fuel mileage and killing your oil way be for it should. Your not doing any lasting damage at all
i have seen guys run them so rich a black puff comes out the exhaust with every movement of the throttle yet they run for a year like that ! lol question: did you look at your float adjustment? Did you adjust that at all or check it ? That could cause a rich issue also ..

Thanks man for the reply. no big deal on trashing the oil, im still on BBK break in period, so ill likely do another change in the next two weeks, i only average 50 miles or so a week, so break in is slow.

Good idea about the float. i haven't tried that at all, i suppose messing the float trim can lessen the amount of fuel in the bowl which might help. I know the little enricher fires off a squirt of fuel and i can adjust that metal flip arm to readjust the time or even disable it, but i dont really have a spare carb laying around i can trust so ill check that float bowl.

Thanks!

[mikeh]

It seemingly did fine this morning on the ride into work, just a slight stumble when taking off but never fully fell on its face. Just have to work on the carb this weekend hopefully. For using more gas, likely have to start spending 6 bucks instead of 3. Scooter life is pretty great. 🤣

[donaldsonta]

I think 33 to 35 is stock for the slow jet on these, so you're probably lean.
I doubt there's any serious damage since our scoots usually operate at 75% throttle or more. I actually just bought a 38 for mine the other day, but it's had similar issues on/off for its lifetime. Mostly if I idle/roll down to a stop if hesitates for a second before accelerating away.

I haven't installed the 38 because it's 18°F here. I'll ride, but I'm not going to tune a carb in this shit.

[3strokeengine]

If you're super rich you run the risk of washing the oil off the cylinder walls and ruining the cylinder.

[GrumpyUnk]

3stroke, I think you need to have liquid fuel coming into the cylinder to worry about fuel washdown occurring.
I do not think an engine would run, or would run very roughly if it had that much fuel.
OTOH, if you have a bad float valve, either sticking or leaking, it could send fuel down the intake and clean the lube off the cylinder walls. I had one with a leaky float, and it would drool fuel out towards the air cleaner, but if the front wheel was on the ground, I expect it would have flowed the other way, and perhaps not only washed down the wall but diluted the oil in the crankcase. Symptoms of fuel contamination are oil that smells of fuel when you check it, or oil level being more than full upon checking when it was not over-full when checked previously. If you have a real leaker, you can also hydrolock your piston if the cylinder gets full of fuel. Cranking with a cylinder partially full of fuel is not a good thing.
tom

[christopher]

Dec 18, 2019 19:40:18 GMT -5 3strokeengine said:

If you're super rich you run the risk of washing the oil off the cylinder walls and ruining the cylinder.

I agree I was going to say if your running a 4 stroke motor that rich, the fuel can wash the oil off the sidewall of the cylinder.

[mikeh]

Dec 26, 2019 13:02:30 GMT -5 christopher said:

Dec 18, 2019 19:40:18 GMT -5 3strokeengine said:

If you're super rich you run the risk of washing the oil off the cylinder walls and ruining the cylinder.

I agree I was going to say if your running a 4 stroke motor that rich, the fuel can wash the oil off the sidewall of the cylinder.

I've continue to ride and haven't been able to plug chop but I think I'm just slightly off on the pilot and maybe the main jet, I usually log 5 miles one way to work and 5 or so home, most is wot. I haven't had the money to get new pilots or main jets but I am planning on getting some next month. The dying out at lights has largely stopped on it's own, I did slightly adjust the idle screw. I need to get the new jets and start over from scratch on my jetting. I can usually see 40 mph with no head wind. Does 35 mph up my local bridge which is steep, on my commute to work.