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08 CRF250r power loss? and MEGABOMB tuning

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Hey all, a few weeks ago i fitted a FMF megabomb to my bike but kept the stock exhaust on it, i went for a ride 2 weeks ago and noticed a bit of a power loss but i know its not from the pipe as its been slowly losing power

I just want to know how to restore this power without restorting to a top end rebuild and could it be with the exhaust i need to re jet it?

all help, advice, tips are more than welcome and i would really appreciate it

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Jetting may need to be changed. I don't know if you have the stock jetting in the 08, but if you do, the first thing to do is replace the main jet from a 188 to a 172. You didn't say if the power is lost on the top end or bottom.

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it could be in your head, best thing thing to do is to ride another bike like yours and compare, how many hours on it? like charlie said it may need rejetting especially if the weather has changed lately..

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oh sorry, i seem to have lost power in bottom and mid. Yes the jetting is stock, only things i have chucked on the bike are graphics, bars, bash plate, header and yeh thats pretty much it, the rest is stock.

I dont really know alot about jetting so how would i go about changing the jetting myself?

anybody have any ideas.

oh yeh and its done about 40-50 hours and i compared it to an 09 crf 250r and my bike was a bit less powerful like you could rev the 09 and the front end would pop up but with mine you really have to give it to it to get it up in the mid and bottom

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oh sorry, i seem to have lost power in bottom and mid. Yes the jetting is stock, only things i have chucked on the bike are graphics, bars, bash plate, header and yeh thats pretty much it, the rest is stock.

I dont really know alot about jetting so how would i go about changing the jetting myself?

anybody have any ideas.

oh yeh and its done about 40-50 hours and i compared it to an 09 crf 250r and my bike was a bit less powerful like you could rev the 09 and the front end would pop up but with mine you really have to give it to it to get it up in the mid and bottom

if you have the manual, directions should be in there to change the jets.

if not theres a bolt on the bottom of the carb bowl and take that off and there are 3 jets you can see. ones the pilot, ones the slow jet, and the other is the main.

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ok i got a whole heap of jets with the spares when i purchased the bike, how do i know which one is the 177 ( i think u said ) so i can put it in and what does it look like.

will i have to take the carb off?

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no you wont have to take the carb off but you take the plug out of the bottom of the carb with a 17mm wrench and then i use a 1/4'' socket to take the jets out. i think the main is the one in the middle hanging down the lowest. it should have a number etched into it and thats the jet size. 188 is stock for the 08.

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ok i got a whole heap of jets with the spares when i purchased the bike, how do i know which one is the 177 ( i think u said ) so i can put it in and what does it look like.

will i have to take the carb off?

Did you check your airfilter?Is it not restricted?

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no the airfilters not clogged

umm with the jets i got with the bike i got 4

2 of them look the same and the other 2 are different, they have numbers and kehin on the packets, looks like a serial number or part number im not sure

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tell us what the part number is on the package and we can tell you what it exactly is..

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ok ill go out tommorow and tell you but just out of curriosity how do you tell? do you go on their website and look it up?

quick question to is the main jet a short stupmy looking thing or is it the long one which looks like a mini silencer?

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The long one with holes in the top and sides and has a flat screwdriver slot is the pilot jet. The short one that is roughly 1/2" long and only one hole from top to bottom and is hex shaped is the main jet. There is a number stamped on the side of the jets which tells you the size of the jet. The main is a high number which for your bike can range from 168-180. The pilot will range from 38-45. Usually it your outside of that range on either, something is wrong. When it's all said and done, you should be at roughy at a 42 pilot and a 172 main. If it's not around there, that's a real good starting point.

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