What am I missing here ?!?!

[BrewCityMusic]

OK, so the project is *this close* to being done, the driven clutch issues I've been having are hopefully going to be straightened out once and for all either way tonight ... But I *still* can't get this thing to run up to RPM's like it should. It starts like a champ, and starts to wind up but then just sputters a bit at maybe 2k and seems to not want to go any higher unless it's not under load (as in downhill, etc). Plenty of good fire, fuel pump spurting like crazy, all new filters, etc, carb and jets totally gone through twice, 128lbs of compression, seals pass the starting fluid test, muffler cracked open doesn't help a bit ...

WHAT am I missing? I know I'm missing the idle adjustment screw, but that shouldn't affect the actual driving RPM's at all (or am I off base here) ... I'm about ready to start pulling my hair out on this one, anyone have ideas I may have overlooked?

[gornoman]

I'm no mechanic, but if the missing screw is allowing an air leak......

[tradermark]

I wish I could help Brew since you contribute so much to other folks including me!!

I just got my first 2-cycle a couple weeks ago and I haven't begun to even think about starting that project until I get my 804 completely redone.

Mark

[BrewCityMusic]

Well, G-man, here's my logic, the idle circuit is actually basically unused in these carts as the carts don't "idle", and once the butterfly opens at all then the main fuel circuit takes over ... I tried plugging it just for grins and that didn't help either.

I'm heading up to the garage to tear the carb off one more time and see what I might have missed (after I pick up some more carb cleaner) - this is really starting to make me need a cocktail, hahahaha

Thanks for the Kudos, Mark - can't wait to see the 804 all done !!!

[kyerik]

I think replacing the idle screw will help.

Does pulling the choke out a little bit help?

[BrewCityMusic]

Actually no - I just went and replaced the choke cable as the old one was pretty crusty and was keeping the choke from fully opening, that helped a *little* bit but not enough to make me say it's acting normal ... I also found a needle valve from a weedeater that had the same threads and tried that backed out 1.5 turns - didn't seem to help a whole lot either (although who knows, it could be a whole different taper, etc)

[Dave Box]

I read the manual and looked at the air flow map and you are right as soon as the throttle butterfly opens the pilot screw by pass line only provides a miniscule amount of air and will have no effect.

Could it be the float switching off the fuel flow to soon? (wild shot in the dark)

Dave

[pachanga90]

The idle-mixture screw will cause it to act funny,as it helps in transistion of fuel,and it will suck air from outside the carb,really reaking havoc on your mixture.Check your float,and lines.A small air-leak(loose-clamp),can cause it to starve for fuel.What about timing?Did you set it correctly,and does it run better in reverse?Also,any leaks around the intake-area(carb,manifold,etc..)will give you a headache.Try unhooking the muffler,see if that helps(plugged or damaged internally).Does the choke help or worsen the problem?Is the spark-plug correct?What is your fuel-mix?If its' too rich,it won't run correct on a fresh rebuild,since the rings aren't seated yet.Is the piston in correctly(there is a front and back).Are the reeds in good shape and fully seated on the plate.Try some of this stuff,or compare it to what you've done.Hope this helps.

[tradermark]

Brew,
Reading pachanga's post made me think about another post I read the other day.
Someone posted about poor performance and what they found was a little seed stuck under one Reed valve holding it open just a smidge. Might be worth a look?

Mark

[sassycat]

wish i could help but you will have it figured out before me for sure..good luck