330r wont hit top end

[250rracer90]

hey everybody i got a 86 250r with the psi 330r pv kit on it psi pipe fmf silencer 40mm carb airbox delete intake ricks hotshot box went riding today took it out in the field opened it up and i got to a certain rpm almost wide open and it wont quite get there acts like it hits rev limiter, figured it was a plug getting ready to foul, took the plug out and it was almost caramel not soaked with fuel or nothing was a real clean burning plug i used the same plug with a tank of fuel before but it ran really rich put to much oil in the gas (my bad) im wondering if thats all it is but when i ran good fuel in it maybe the plug cleaned off and still isnt firing right? i dont no what else it could b besides moving the needle up in the carb or something, any help would b appreciated

[baycitysteve]

what's a hotshot box ?? if it's like a roost boost i'd take that off or if has anything to do with the spark or ignition ..

[250rracer90]

its a direct replacement for the stock cdi box its suppose to increase spark, increased rpm redline and altered ignition advance curves, Advance curve allows ATV to rev at higher rpm and quicker rate, Also may be used to replace defective CDI box on stock machines

[Chazz of Blades]

Yeah, it's probably like those Big Gun kits, utter crap.

[250rracer90]

hopefully not my stock cdi went bad on me and i wasnt going to put a stock one back on it or buy one used i think ill try throwing a plug in it if that dont work then its gotta b that damn box

[RIDE-RED 250r]

Check your reed petals before condemning your Hotshot CDI. I have one and it works great. Make sure your reed petals are closing all the way and not fraying or cracking.

[250rracer90]

Ok ill take a look at them tomorrow

[rdlsz24]

How old is the clutch? My 85 was acting like that when I first got it. It would rev up but not want to go faster on the top end. I replaced the clutch and it fixed the problem. I thought it was jetting or intake at first also.

Rob

[rjs89ia]

I've heard that stock ignition and maybe even retarding the timing on a big bore engine is better. I run an rpm advance retard plate on my 310 and i think i run it at around 1 to 2 degrees retarded and it runs clean or did until i took it apart to rebuild

[250rracer90]

clutch is ok it dont slip, heres what i came up with though took the reed cage out and i dont no if this is normal or not it dont look like it but the center of the reeds look like they ate away just the first stage, i no they dont look like that brand new they also look off center with the second stage, second thing i found was the breather tube for my powervalve was rubbing on the pipe and it closed itself off so the powervalve couldnt release pressure so i imagine its loaded up, i took the plug out and i was running lean plug was almost gray not chalky but just lean, im thinking that hotshot box screwed with my timing enough to throw the carb out of tune and i just need to go back threw it and set my air screw again, i got some pictures of the reeds and i took a picture of the inside of the intake port to show what i mean about how the reeds could have ate up they look like theyve hit the pillar in the middle of the intake but my guess is as good as anybody elses, i really think i just need to take time to sit down and retune, mayb reeds?.....
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[RIDE-RED 250r]

What kind of reeds are those? Im not liking the looks of pic #1. Seems kicked off center, like you said. Also, if you look at the reeds from the engine side, are they laying nice and flat against the cage or is there a gap?

[250rracer90]

there boyesen carbon fiber reeds 2 stage same thing i got on my trike, they lay flat there very stiff i put my finger nail under each side on each stage and pick them up a little bit they have plenty of snap still to them, they just looked screwed up lol

[RIDE-RED 250r]

OK, sounds like they arent too worn. No fraying, cracking or chipping on the leading edges? If so, straighten those 1st stage petals and give it a try. One thing at a time....

[250rracer90]

not from what i can see, they look fine to me ill straiten them out and see what that does hopefully they didnt crack under the hold down plate and thats why there off center....

[Dirtcrasher]

I only browsed through this but: When I'm too lean, the top end never top outs, 4 stroke or 2 stroke. Fatten the main up a bit and see if it stays the same, sputters or takes off like a rocket. 15$ in a few jets is well worth trying....

[250rracer90]

it was running lean im gonna straiten them reeds out change the plug and mess with the airscrew some i no i got a rich enough main in it im running a 195 i really havent played with this carb enough yet it ran kinda rich when i first got it but it ran great then the counter balancer holder went bad i put that cdi box in it had a air leak in the motor and it hasnt quite ran right since i didnt ride it with the air leak i no it didnt damage the motor, its gotta b something with the carb if it isnt the reeds after i reposition them

[fabiodriven]

I bet it's all the capitol letters and punctuation you're not using clogging the fuel filter.

[250rracer90]

i didnt no this was english class

[250rracer90]

reeds aint the problem all of a sudden it just runs lean after i put that cdi box in there i checked for air leaks in the motor and i dont have any, my air screw is out 5 turns, main jet is 195, and im fairly certain my pilot is 45 ill have to double check, another thing i noticed that it never used to do is when i start it i have to sit there and play with the choke, without the choke on i can give it gas and it will want to die like its not getting enough fuel, let it sit and idle long enough though click the choke off and its fine, once it gets going bottom range to mid is excellent ton of power starts hitting high r's like its about time to shift it and it sputters, i got some pictures of what the plug looks like i did a plug chop 6th gear pinned let it sputter a couple times and shut if off and heres what i got.
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[RIDE-RED 250r]

It does look a bit lean. Try stepping up to a 200 or maybe even 205 main. Im not sure how the CDI would affect your jetting, but the plug chop doesnt lie......

[250rracer90]

unfortunately it dont, that box is suppose to change the timing curve i cant think it would change it enough to throw the jetting off, i think ill take that jet i got in it now to work and bore it out just a little bit and see what that does we got the machines to do it might as well save myself a hassle on waiting for parts

[ceaserthethird]

I'm speechless on your quick fix's!

Keihin Carb only ~ 38mm - 40.5 mm

1. Air / Fuel mixture ~ 2 or 1 3/4 turn out from lightly seated

2. replace your pilot jet - 48 / 50 / 52

3. Put the STOCK OEM CDI back in, Want something that works better Buy a ESR CR ignition kit !

4. Do a compression Test - anything over 200 psi ~ Run Race Fuel 110 Octane

Just some pointer's to start with...

[ChrisD]

1 get rid of that CDI box. They are crap. But even a used OEM.

2 my 330 motor with a 40.5 PWK went down from a 190 with the 250 motor to a 175. Bigger doesn't mean you need a richer jet. The larger volume piston pulls more fuel through the jet so in most cases you will go down in jet size. Also, your pilot jet is too small. You should to to a 60 pilot.

This is just from my setup and experience. I hope it helps.

[TtownJoeShow]

I'm speechless on your quick fix's!...

beat me to it!! lol

Excellent advise!!!!

[fxnteeth]

My R had top end problems also 75% sputter no matter the jetting and the main jet looked the same on plug chops from 150 to 200. IN other words it was never reaching the primary use of the main jet. I replaced everything electrical in the bike except this "badass CDI box" Yes, the dynatec was messed up. It was brand new, but after I replaced it, it ran like a champ. It produces a curve at every rpm level. My box was screwed on the topend. hope this helps. Try a box off of a friends bike for diagnostic purposes

[250rracer90]

got my jets today ended up running a 200 main kept the same pilot turned the airscrew in to 2 1/4 to start with first kick it fired right up no hesitation at all, did my plug chops every plug came out caramel color to dark brown and it runs better than it ever has. guess ill get a couple more rides in this year and itll b time to get the sled out :D