Uni dirty?

[evilone]

My OKO 28 has been bogging at wot (when taking off from stop, i have to let off throttle to get it going). Any chance it's from a dirty Uni filter? It seems to be getting worse little by little. Or am i looking at a carb cleaning? It ran great until recently when it started acting up.

[burnt_toast]

yes could be filter. take off, ride without, and see what happens

[evilone]

Ok, here we go. Below is a video of problem, it's idling on center stand then i give it WOT, it stalls. I've tried main jets #135, #138, #142, #145 all with same result. I have the gas tank screen removed with an inline free-flow filter and filter is very clean and not clogged at all. Uni filter was removed with same result too. I did have a problem with fuel coming out the bowl overflow but fixed that and it ran great.

http://s481.photobucket.com/albums/rr17 ... IM3110.flv

One more thing, i did recently get cylinder ported. Below are pics. Problem was there before port job, now it's just worse.

BEFORE PORT.



AFTER PORT.


BEFORE PORT.



AFTER PORT...A LITTLE REMOVED FROM SKIRT FOR BETTER FLOW.


Here's my setup if it helps.
Malossi 72cc, ported cast iron cylinder
8:1 gears
28mm OKO, 48 pilot, usualy run a 138 or 142 main, clip in middle position.
CT manifold and reeds
UNI filter
Boost port has been ported to match Malossi cylinder
R1 28mm muffler (not the 26mm)

[burnt_toast]

I did have a problem with fuel coming out the bowl overflow but fixed that and it ran great.

how did you fix it?

sounds like its flooding. inspect float valve

and on sidenote 48pilot's kinda low, 52better 138-142main mid clip is good

[Arnadanoob]

If I understand the problem, the engine is bogging to the point it just dies when you snap the throttle wide open from idle. That is the result of the pilot jet being too small and in severe cases it could be that your needle diameter is too large (lean).

The first thing to do is reset your air screw on your carb to 1.5 turns out, clip in the middle for needle. Put in a 135 or 138 main jet just for starters. Start with a 52 pilot and work your way up.

[evilone]

Awhile back i found one of the 2 floats bent so i bent it back and that seemed to fix problem. I'll have to take apart and check again, funny thing is i haven't opened up the carb since the bowl problem. I'll try the jets you recommended too. So did the porting job look good?

[evilone]

Arnadanoob, i have the air screw set at 1 7/8 turns out and it seems to idle good at that spot. But i'll try bigger pilot since the cylinder is now ported, it's starting to make sense...i think . Now that i think about it, before cylinder was ported there was a decent amount of smoke coming out muffler. After the port i didn't notice any smoke=too small pilot, hmmm.

[evilone]

I bumped the pilot up to 52 and main to 138 which is what i usually run and it's all good now. Guess what size pilot i had in there? .............a 42 . I have no idea what happened there...must have grabbed the wrong size when i thought i was putting in a 48. I'll leave it where it is now . Any comments on the cylinder porting? I found the Malossi ports are smaller than stock

[bakaracer]

its hard to tell by the pics you posted.take more pics in different angles.Did you change the height of the port windows piston side?

[burnt_toast]

I bumped the pilot up to 52 and main to 138 which is what i usually run and it's all good now. Guess what size pilot i had in there? .............a 42 . I have no idea what happened there...must have grabbed the wrong size when i thought i was putting in a 48. I'll leave it where it is now . Any comments on the cylinder porting? I found the Malossi ports are smaller than stock

doh, at least it was easy fix