jetting on my 96'

[clayton00grand]

Ok the bike has 28mm Mikunis on it no TORS, bored I want to say .020 over, K*N air filer, stock lid aftermarket pips and silencers, not sure what brand but they are pretty big by the gas valve area they actually almost rub there, ailencers I believe are answer ones. Reed spacers and boost bootle. Main jets are 240. I tried to take air lid off and it did not help what so ever. It was reworked about 7-10 years ago havent really ever rode it to hard not much time for that. I almost forgot a Pro Design cool head and running 93 octance and Amsoil Dominator racing oil, 32:1. Also 4 degree timing advance. Anyways, riding in say 1/2 to full throttle its fine but done low it really seems to lack any power, I used to be able to pulled the wheels up to 4th gear and ride a fairly nice wheelie. now even 1st won't pull the front up. Is it a jetting problem or is the old mule just ready for a tear down? It doesnt lack any top end to my knowledge anyway but the low gears quicking recing really puzzles me. I thought about thowing a 250 jet in there and seeing what it does but am I waisting my time. Carbs are nice a clean been off recently Any thoughts woudl be great. Thank you

 

 

[Handyman]

If it's been bored, you are running lean....Try starting with a 300(or close to it) and put in a bigger pilot it's the stock one(seems to help on the bottom end)...You have a bigger bore than I do and I run a 310 main with a 27.5 pilot. Every motor is different and you may have to play with the jetting a bit...

 

Also try turning your air screw out 1-1.5 turns from out from fully seated.

 

Elevation plays a big role in jetting as well..

[clayton00grand]

What is throwing me it ran for so long now its giving me trouble. I am wondering if its age on the rings finally is catching up with it. I have literally not popped things apart since the complete rebuild back about 8 years ago never needed also ran a raped ape, and even better after the 4+ degree timing advance that really woke up the low end. But now things don't seem to run worth a crap unitl you hit the major powerband and even then kinda seems to sputter a bit. I can barelly pull the wheels in 1st heck before I could could let off the throttle and smack it again in 4th and it would stand up and wheelie riding I was going.

 

If it's been bored, you are running lean....Try starting with a 300(or close to it) and put in a bigger pilot it's the stock one(seems to help on the bottom end)...You have a bigger bore than I do and I run a 310 main with a 27.5 pilot. Every motor is different and you may have to play with the jetting a bit...

 

Also try turning your air screw out 1-1.5 turns from out from fully seated.

 

Elevation plays a big role in jetting as well..

 

[clayton00grand]

Ok today I pulled carbs out and cleaned them all up I didn't see anything in them but thought what the heck. I had talked to Vito's and realize that I had my reed spacers on wrong side of reed so I switched that around. I measureed my carbs they are definately 28mm He said with lid on I should be around the 240-250 main jet which is what I had in it, and about 280 or around there without airbox lid. He also suggested that I look at the degree key I put in and make sure it hadn;t slipped and done anything in there key loked perfect. Now I am completely out of guess. This is just a recent accurance heck just a little whilele ago I was riding wheelies 1-4 gear no prob now the fron wheels won''t even come up in 1st gear Does anyone have suggestions, we looked at the pistons when had reeds off and everything they looked good from what you could see faint scratches but thats it.

With me flopping the reed spacers around it definately helped the low end but the fact that I can not pull wheels is bothering me when I put carbs back on let fuel get to them it wi fired up first kic, once warm it has always done that. top end it seems great. Please help I have noticed whether or not it is anything or not, when I check tranny oil it always seems to be low is it possible that I have a seal that went bad.

 

 

 

What is throwing me it ran for so long now its giving me trouble. I am wondering if its age on the rings finally is catching up with it. I have literally not popped things apart since the complete rebuild back about 8 years ago never needed also ran a raped ape, and even better after the 4+ degree timing advance that really woke up the low end. But now things don't seem to run worth a crap unitl you hit the major powerband and even then kinda seems to sputter a bit. I can barelly pull the wheels in 1st heck before I could could let off the throttle and smack it again in 4th and it would stand up and wheelie riding I was going.

 

[AKheathen]

Ok today I pulled carbs out and cleaned them all up I didn't see anything in them but thought what the heck. I had talked to Vito's and realize that I had my reed spacers on wrong side of reed so I switched that around. I measureed my carbs they are definately 28mm He said with lid on I should be around the 240-250 main jet which is what I had in it, and about 280 or around there without airbox lid. He also suggested that I look at the degree key I put in and make sure it hadn;t slipped and done anything in there key loked perfect. Now I am completely out of guess. This is just a recent accurance heck just a little whilele ago I was riding wheelies 1-4 gear no prob now the fron wheels won''t even come up in 1st gear Does anyone have suggestions, we looked at the pistons when had reeds off and everything they looked good from what you could see faint scratches but thats it.

With me flopping the reed spacers around it definately helped the low end but the fact that I can not pull wheels is bothering me when I put carbs back on let fuel get to them it wi fired up first kic, once warm it has always done that. top end it seems great. Please help I have noticed whether or not it is anything or not, when I check tranny oil it always seems to be low is it possible that I have a seal that went bad.

do a compression check. what's you're temp/elevation?

[clayton00grand]

I'm in Ohio so pretty flat don't konw exact elevation, 120 both cylinders. I talked with vitos again and before that I look at the start while I had flywheel off looking at advance key, and the 2 towers that are across from the pick up coil are blackened and somewhat soft and it looks like one of them has melted away a bit. He suggested that maybe I had a weak coil in the stator because after I rode it there was fuel mixture on the plug still, and that maybe because of that of that he would be thinking it was the stator. next thing would be crank seals. Any thoughts.

 

 

do a compression check. what's you're temp/elevation?

 

[dajogejr]

Can you get us a picture of the carbs please, so we know if they're stock or 28mm?

 

Bad/faulty ignition components will have you chasing your tail all day long.

120PSI from a reliable gauge is only a few PSI less than stock...what brand compression tester is it?

 

Unless you have a shaved head or smaller domes in the bike, I'd look elsewhere.

 

If you had a crank seal go bad on the tranny/PTO side, you'd be fouling a plug and it would run even worse on top.

Remove the reed spacers.

A compression test will not reveal bad crank seals, but a leak down test will.

[clayton00grand]

Compression tester isnt the problem, its not a cheapy, and yes it is a 120 psi and always has been, and yes they are 28mm mikuni round slids.

 

I' starting to wonder about the stator.

 

[AKheathen]

Compression tester isnt the problem, its not a cheapy, and yes it is a 120 psi and always has been, and yes they are 28mm mikuni round slids.

 

I' starting to wonder about the stator.

the stator does sound pretty questionable. what's your pickup gap set at? has it warmmed up, or got really humid reecently? what do the plugs look like?

[RagunCajun]

If you can, grab a buddy's stator and try it. Same thing with other electrical components. I had a problem once. Turned out the pickup by my flywheel was too big of a gap. Man i chased that problem for weeks and weeks.

[Building my First]

Reeds??

[clayton00grand]

Over the winter I had popped out my reeds and looked at them everything was fine then no cracks or anything , I just check pickup gap last night it was .021 and I set it to .018 per vitos and the book I have for it.. The only 2 things I can think of is that reeds went, and maybe the stator.

 

I also rode it around it was pouring rain last night so didnt ride too much , but I took temp of pipes when I got back inside and the left side was 121 degrees and right side was 98 degrees. Once warm this thing kicks over awesome and starts everytime first kick (knock on wood).