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crf230 jet mod.. but bogging at full throttle? please help

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2004 crf230 here.. did the jet mod with the new needle and main jet today.. removed the baffle from the exhaust and the top of the airbox as well..

runs fine till i hit 4/5ths or full throttle then it just bogs.. and almost dies.. perfect otherwise but top end and at higher speeds its like its at only 3/4 throttle any more and its bogging..

 

ive adjusted the idle screw and and the fuel screw but not sure where it should be.. seems to idle fine...

 

is this a back pressure issue? 

 

i put the baffle back in and now its fine no problem at all.. i thought the new needle and jet would fix the issue of the baffle being removed..

any suggestions?

 

thanks

 

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2004 crf230 here.. did the jet mod with the new needle and main jet today.. removed the baffle from the exhaust and the top of the airbox as well..

runs fine till i hit 4/5ths or full throttle then it just bogs.. and almost dies.. perfect otherwise but top end and at higher speeds its like its at only 3/4 throttle any more and its bogging..

 

ive adjusted the idle screw and and the fuel screw but not sure where it should be.. seems to idle fine...

 

is this a back pressure issue? 

 

i put the baffle back in and now its fine no problem at all.. i thought the new needle and jet would fix the issue of the baffle being removed..

any suggestions?

 

thanks

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WOT is main jet. Your symptom is a too-lean main jet.

 

That's a very small, constricted motor.

You can't expect miracles with just a minor un-corking and re-jetting.

 

Try a main jet up two sizes. If it gurgles, you've gone too big.

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stock 04 needle works well just change the clip position

you need to tell us what size main and pilot your running

I seggest 45 or 48 pilot and 115 120 main

recheck your float level and wet set it

go into the Honda crf 150/230 page and read up its in the stickeys

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It's been stated here a thousand times already , but again, use the Mike Coe Show jetting specs only.

This is for a bone stock bike with at least a UNI or a TWIN AIR air filter, no baffle on the top of the air filter box (removed) and remove the SMALL baffle in the exhaust (leave in the spark arrester screen)

Forget the power up needle and the 132 main jet!!!!

ONLY Use the stock needle and move the clip to the 4th notch from the top.

(Only one 1 notch showing under the clip)

Install a # 45 idle jet (minimum) if your bike still pops on decell then install a #48 idle jet.

Coe Show specs require a #118 main jet. In my experience and opinion, That should be good up to 4000-5000 feet elevation. If you ride at sea level only, you can use a #120 main jet.

Start with 2/12 turns out from fully seated on the idle mixture screw.

For the best running operation possible,

Adjust the valves with a dead cold engine to factory specs. Take your time, do it correctly. If you drive hard and are an aggressive rider use premium pump fuel.

Air cools bikes under high load at slower speeds can use premium just to be safe. They will ping and detonate when they are over heated. ( yes even when stock)

Make sure the spark plug is in great condition and always check the gap.

Don't assume that it is gapped properly.

If you drive hard, at a high rpm, in hot weather, you can use an NGK J9A spark plug. (Colder than stock)

Want more power ?

(every little thing helps and adds up)

Remove the weld build up in the exhaust header where it bolts up to the cylinder head. Then remove the restrictor in the muffler right behind the gasket where the header slides into the muffler. ( this mod world best with an oversized header. (Powroll)

Hope this helps,

Guy

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thanks for the tips guys..

ive got the power up needle in and paid $30 for it so im not gonna give up on it yet.. as mentioned low end is fine its the high end thats bogging out.. ill adjust the fuel screw and order a 120 main from the dealer and try that.. i also will put in a new plug and a new twin air filter ...try that out

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I hate to say it but throw away that crap power up needle newfie

go with the mike coe recommendations -you asked for help so pay attention

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The power up needle will work fine, just change the jet. Some where in one of the post Mike Coe states that the power up needle actually worked better at lower elevations than the 03-05 needle. Just get a 120 main a 45 pilot and you'll be set.

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well i adjusted the a/f jet again today , turned it all the way in (which i didnt do last time) and then 1.75 turns out... also just cleaned the spark plug which was a little black..

Fixed the issue.. now the bike will lift the front tire much easier and no bogging in the top end.. pulls hard all the way up to redline..

 

so im not gonna change anything..  as its all working great now.. 

thanks for all the input though guys

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