@#^$&%!!!!! HELP...

[msb3671]

Hey. Nice weather, no?

I got my scoot running again, new CDI, coil, Iplug, clean carb w/ 88 main jet, UNI filter.

Still won't hold an idle at lights, and my power is NOT like it used to be.

Any ideas?

Thanks!

Add: I'm having a whole lot of trouble with the air/fuel mix. No setting seems to work.

[90GTVert]

I think it was suggested in another thread, but have you checked for vacuum leaks yet?

[tomcas]

I agree vacuum leak and also possibly plugged idle jet, misadjusted float level, valve clearances.

[msb3671]

Valves set(adjusted), checked for vacuum leaks. None, that I could find. But for the other noobs, what exactly do you mean by valve clearance?

My pilot jet seems clear; its been sprayed and blown(does NOT sound right), but I have a new one on the way as of this evening. Larger.

Float level seems good according to Brent's carb post.

I did notice better main jet 'action', and the UNI at least sounds cooler. The coil & plug make for a much more 'live' start. Not sure if CDI changed anything, but I think I'm just replacing all OG China parts that I can at this point.

Scoot runs really well for about a minute, right after start up. Good take off, motor sounds good, good power. Then blah. Also sometimes hard to restart at redlights; have to let it sit a minute. Sometimes(often) have to give it a little gas during restart too. When it does idle for a bit, it revs with no apparent pattern. Not high revs, but waves of up and down.

I'm going to replace the pilot jet as mentioned, and also the auto-choke. Petcock as well. These are cheap enough, and from what I have read here, could be part of the problem, or go south in the future.

Could the lack of power be my vari or clutch screwing up somehow? I have lost a lot of power on hills...

I got to ride a bit today. It was beautiful out.

Ideas? Thanks!

[Fox]

Oct 24, 2010 19:41:45 GMT -5 msb3671 said:

Valves set(adjusted), checked for vacuum leaks. None, that I could find. But for the other noobs, what exactly do you mean by valve clearance?

[msb3671]

Yeah, that's what we did two weekends ago. But thanks!

Question: Where are the 'most popular' places for a vacuum leak on the GY6? I checked the hoses and the intake mani, and the valve cover.

Thanks!

[Fox]

I think the UNI filter may be the issue. An 88 main jet may be too small to use a UNI filter on there.

Try installing the stock air filter back on there and see if it improves.

[msb3671]

Ok, but I would like to go with the UNI. What size jet do you recommend?

It's an 88 right now.

Thanks!

[Fox]

One step at a time...

Try the stock air filter before we get into that. If it improves with the stock filter then you'll need to go bigger on the jet with the UNI but first things first. Try the stock filter.

[msb3671]

10/4. ;D

[stepthrutuner]

Oct 24, 2010 22:25:17 GMT -5 msb3671 said:

Ok, but I would like to go with the UNI. What size jet do you recommend?

It's an 88 right now.

Thanks!

I suggest starting with at least a 100 and probably no bigger than a 105. The book says to go from rich down to the proper mixture, but this is not so critical with four strokes so tuning from lean up to the proper mixture is ok with four strokes. Every set up is a little different but I will speculate that a 100 will be within two sizes of the proper main jet. A proper plug read on a four stroke is a light tan. If it's white you need to add more gas.

[Fox]

If you have a movable clip on the carb needle, try moving it all the way to the bottom slot. That will increase the fuel a little.

[shakerdriver]

also check the diaphram in the top of the carb for pinhole leaks or cracks.

[msb3671]

Hey guys. Hope all are well.

I switched back to the stock airbox; no difference. Thanks though, because it made me try running it a bit with no filter; no better there either.

I had already moved the clip on the jet needle to the 'most gas' setting when I cleaned the carb. Pretty sure I re-assembled correctly, but I'm going to verify that when I have some daylight. I have cleaned carbs on many lawn tractors and this scooter before(using the video found here). Hard to screw up with a teaching aid like that. But, I'm gonna check it. Diaphram looked good; held it up to a light(the sun); no holes evident.

Could any of these symptoms(loss of power, hard starting, no idle at red lights) be caused by something in the drive train? Just noob wondering. As a noob, I know I DON'T know alot, but this problem seems to be originating somewhere other than the air/fuel/carb/valve areas. Just me thinking, which can be faulty.

What recommendations have ye?

Ya know, for as much grief as this scooter gives me, I really enjoy working on it.

Thanks! ;D

[Fox]

Oct 25, 2010 23:03:15 GMT -5 msb3671 said:

I had already moved the clip on the jet needle to the 'most gas' setting when I cleaned the carb.

So you changed the clip already. That shouldn't make it run crappy but you might try putting it back.

Oct 24, 2010 19:41:45 GMT -5 msb3671 said:

Scoot runs really well for about a minute, right after start up. Good take off, motor sounds good, good power. Then blah. Also sometimes hard to restart at redlights; have to let it sit a minute. Sometimes(often) have to give it a little gas during restart too. When it does idle for a bit, it revs with no apparent pattern. Not high revs, but waves of up and down.

It's possible that guy at the shop didn't do the valves right. I mean if the gaps are too small then it could run good til it warms up and then lose compression after the metal expands because the gaps go away. Was the engine room temp when he did 'em?

The other possibility is a faulty auto enricher. The carb has an enrichment jet that supplies extra fuel to the engine so it runs rich when the engine is cold. Then after a minute or so the enricher needle extends outward cutting off the enrichment jet passage effectively leaning the mixture out. It really should be called an auto-leaner IMO but anyway, if the enricher goes bad then the mixture will always be too rich so it'll run good cold for a minute and then once warmed it'll run crappy and won't want to idle. Un-plugging the enricher will make it act like the enricher is bad. Maybe the guy at the shop did that in order to force you to have to bring it back. There's some shady characters out there who will do shit like that.

To check the enricher, you remove it, measure the distance the needle protrudes from the enricher's body, hook the leads to a 12 volt source and wait 1 minute and re-measure. It should extend by a few mm's or so.