Think I need to rebuild the top end By blu (Read 499 times)

[blu]

I've got about 11,000 miles on my Helix clone.  Last spring I had a fuel problem.  My "diagnosis" of the fuel pump showed it was good, but I messed up, it was the fuel pump ll alone.  But since I thought the pump was good, I continued.  Frustrated, I went down to the local scooter guy and had a chat.  He said I might need to adjust the valves.  He showed me the little butterfly adjustments.  So I went home and messed things up.  It's run good, except for a few failures, but it ran good and strong.  It ran a little lean, but it ran good.  The front butterfly (intake?) was almost all the way to the back, so I put it in the middle.  Well, that didn't help.  So I finally figured out it was the fuel pump, so I replaced it.  Got it running, but it's run like crap ever since.  If I warm it up and let it idle, it runs best with the front butterfly in the middle, but it foul plugs and gets terrible mileage.  If I put it back where I found it, it lacks power and runs like crap.  The other day I cleaned up the plug and put the butterfly almost all the way back and went to the park, about a 15 mile round trip.  It was weak but ran, for a while, by the time I got home, it died right at my front step.  I think I've really messed up the valves.  So I'm going to order a new plug for it, think I'll take the carb apart and clean it.  I should take a look at the valves, but I've never done that kind of work on such a small engine.  So what do you mechanics think?  Think I f'd up the valves?

[cyborg]

Doubt it,,,not enough miles,,I'd think the valves are ok,,,,,go on YouTube and watch a few videos on carb rebuilding /tear down and inspection ,,,I think your issue is th carb and valve adjustment,,,also you may want to check the new fuel pump,,,it may be putting out too much pressure. If you can find a mechanical regulator get it in line and st it to 2. pounds

[blu]

Good to hear, thanks. It doesn't make any weird noises, so I don't think it's falling apart yet. Supposed to be less humidity this weekend, I might get some wok done on it, just to hot to do anything outside.

[blu]

Well, I just took the carb apart, everything looks good. Diaphragms are intact. No crud, passages and jets are clear. I'm wondering if the auto choke is working properly. I have a new one, maybe I'll put that in. You ever seen one fail? How did it behave?

[cyborg]

Ya th auto choke (enrichner) mess up quite often

[blu]

The one on the right came out of of it. The one on the left is a new one I bought off eBay a couple years ago. They don't look quite the same. After much ado (I lost the mixture screw behind the starter) I got it back together. It starts and idles just fine. But when I go to go down the road, it misses, and the hotter it gets, the worse it gets. I don't know what's going on. I'm going to have to take it to the shop and get raped.

[cyborg]

Are you sure the valves ar adjusted correctly?,,this sounds lik when it's getting hot after very thing expands the valves are hanging open,,,after it gets hot turn it off then try to restart it,,,,if it's very hard to restart the valves very well may be not closing

[blu]

Took it to the shop. $80......dirty aircleaner. Lessons are expensive.

[cyborg]

Great glad you got it sorted out

[blu]

I've had dirty air cleaners on everything I've ever owned, and none causes the problems this thing did, to the point I couldn't ride it. I've ordered a racing air cleaner that allows maximum air flow. The one that was on there was a K&N type with the oil saturating the cleaner. Never liked those things, by nature, they restrict air flow. Running without one now, but it's not dirty here, it will be ok for a week.

[cyborg]

I run them I like them myself