Honda Spree and Elite 50 Forums

ok so finally got a little time to wrench on the scoot. first had to solve a leaking pet *, then onto slow jet tuning... thats where it gets fun. as some of you may remember i was having an issue with it only starting with the throttle at about 1/4 throttle and the choke/enrichment circuit being engaged only made it worse. so think it would be rich right.
ended up working my way from a 45 to a 32 (which is the smallest slow jet ive got. and it is closer, will now start with just a crack of throttle and almost idle if i hold the throttle barely open...
is it possible that with a 19mm carb that i can run a 30ish jet? granted this motor is only 63cc. but it just doesnt seem right...
since were talking idle here main should be completely uneffected so i dont think backing down the main should really help any should it?
plug is also looking pretty wet as well.

How many turns out is the mixture screw?

Red Eft Performance wrote:How many turns out is the mixture screw?

i preset both of the adjustment screws 1 1/2 turns out and fiddled from there.

You have a 19mm oko?

I suspect that the slow jet is still just too big.

I was only able to find oko that small in their blk version available from treats... I really just cant imagine that it is still to large!

turns out that a 35 pilot is the smallest oko/keihin jet that i can find on line...
im gonna let the jetting wizards like baka and bear weigh in on this before i do anything though.
i guess i may have to sacrifice the low end response and up the carb to a 21 but i dont think it is necissary since wheelman ran a 17.5 arreche on his and got it to run just fine...

Idk, it could still be big.

My 21mm runs the 40-42 pilots well with the needle clip on the top notch.

Have you adjusted you needle clip position at all?

Not that it matters but the Malossi kit is 65cc. The way I figure out pilot size is usually by using the mixture screw to make a educated guess. Try turning the mixture screw in or out and figure out which direction makes the condition better or worse. If turning the mixture screw out 2 turns plus makes it better than the pilot is too big. On the other hand if turning the pilot screw less than 1 turn out makes it better than the pilot is too small. Opening the mixture screw adds air to the circuit and closing the mixture screw takes air away from the circuit. when you get the pilot close turn your mixture screw about a 1/2 turn out and slowly keep turning it out a little bit at a time until the highest idle is achieved.You want your highest idle to be in the 1 to 1 3/4 range. if your highest idle is achieved above 1 and 3/4 turns out than your pilot is still a little bit too big drop a size and try again.If your highest idle is achieved at less than 1 turn out than your pilot is too small. Once your highest idle is achieved between 1 to 1 3/4 you are probably good on your pilot jet. then adjust your idle screw for a good idle. Ive used this method to tune alot of bikes from scratch. everything from mopeds to rd250s.

If your float level is too high it can cause what your describing also.

turtle13 wrote:turns out that a 35 pilot is the smallest oko/keihin jet that i can find on line...
im gonna let the jetting wizards like baka and bear weigh in on this before i do anything though.
i guess i may have to sacrifice the low end response and up the carb to a 21 but i dont think it is necissary since wheelman ran a 17.5 arreche on his and got it to run just fine...

the 35 pilot should be ok. when the bike is at idle, does gas drip out the over fill hose? you can turn that air fuel screw all the way to 2 1/2 turns out if you have to on these carbs. if your at 2 1/2 turns out and its still rich on idle,then your pilot is to big. what do you have the plug gap at? what plug are you using? gap the plug to .024

I am going to try to make time to pull the cooling shrouds sometime in the next couple of days and look for leaks and check to see if the head bolts loosened up at. At this time it will not idle at all, but I did not think about gapping of the plug at all. I was more concerned with getting it started to think about plug gap. But if its set too wide then it would need the extra juice from it reving possibly for it to actually ignite the fuel possibly. I adjusted the float to where I get no more fuel spewage out the overflow, so that's not as big of concern now.
Just gotta get this guy idling so I can start the heat cycling this guy. If all else fails I guess I will order new gaskets and start from square 1...

bakaracer wrote:

turtle13 wrote:turns out that a 35 pilot is the smallest oko/keihin jet that i can find on line...
im gonna let the jetting wizards like baka and bear weigh in on this before i do anything though.
i guess i may have to sacrifice the low end response and up the carb to a 21 but i dont think it is necissary since wheelman ran a 17.5 arreche on his and got it to run just fine...

the 35 pilot should be ok. when the bike is at idle, does gas drip out the over fill hose? you can turn that air fuel screw all the way to 2 1/2 turns out if you have to on these carbs. if your at 2 1/2 turns out and its still rich on idle,then your pilot is to big. what do you have the plug gap at? what plug are you using? gap the plug to .024

ok so after round one of tinkering today i made sure that everything is tightened up and leak free. dropped the slow jet to 32. with an empty bowl it will idle, but as the bowl fills it will start to bog down and not hold idle. no more spewing gas from the overflow, so thats all good now. i think i may try putting the stock manifold and carb on to verify that it is infact a carb issue.
on the other hand, if i up the carb size to 21 i would in effect have to bump up my jet sizes as well, correct? so in turn this could solve my jetting issue if it is infact a too big of jet in a too small carb issue correct?

ok round tow of tinkering is done... and so am i.
this thing is beyond * me off.
put the stock carb with a 90 jet on the block and it is still starting from empty float bowl, but not with the bowl full.
hand over exhaust will kill it. so no horrible exhaust leak.
no noticeable leaks around the base gasket.
intake side gaskets were a little "soft" when i pulled them off.
no noticeable leaks from around the oil pump. (havent sprung for the plug yet, so im using the pump as a plug)
so i definitely dont think it is simply a carb issue. ive gotta have a leak somewhere, now i just gotta tear it all the way back down to find it...

that sucks dude, i hate to hear you are having such trouble

Do a pressure test! I pressure test just about every motor I put together. Many times finding little tiny air leaks that you would have never known were there. It saves so much time and heartache in the tuning process. Nothing sucks more than trying to tune around a air leak.
http://www.youtube.com/watch?v=ySu2NC1X7s4 Keith