FMF Pipe - PW80 ?'s

[summitboy]

I have a new FMF pipe for my boys PW80. It never came with any jetting specs. I am going to run it more or less with the stock air box, but with a piece of UNI foam or equivalent to replace the factory filter. I need to know what jetting to use, or does the stock jetting remain and adjust the needle. Can't seem to find any info. Thanks

 

[Patman]

Did you look on their web site? They offered jetting suggestions for various pipes in the past.

 

[summitboy]

Pipe

I went through the website but the PW80 is not listed and there is just the generic instructions for the Powercore 2. It seems like some guys are just dropping the needle 1 clip from stock and running the stock jet thus far.

I am ordering a Twin Air stock replacement, and Boysen reeds so i was just curious if it might need some thicker jetting. Anyone ?

 

[Patman]

Check the 2 stroke forum there should be a jetting guide thread there. It won't be a you need exactly this brass for your bike but should give you a good idea of how to properly jet based on your bike, mods, and location.

 

[mx-dad]

I wish i could get an fmf pipe here in OZ for a realistic price.....the pipe is $449 and the silencer is $250 over here, absolute robbery

 

[summitboy]

Has anyone installed one of these on a PW80. I checked with FMF and they said tp go up one size on the pilot. I see someone said they went to a 35 pilot which worked but that seems way to high from a 15. Anyone else ?

 

[summitboy]

I did some fine tuning roday. I noticed the 17.5 pilot would still produce a bog/throttle delay from dead stop. I threw the choke on half and it was perfect. No bog from full stop. I then slowly worked my way back up to the 30 pilot. I have it pretty much spot on now. I still can't believe the FMF pipe made that much difference on the pilot which is very rare.

Final jetting (Calgary 3500 ft ASL):

130 Main
30 pilot
pilot screw 1 3/4 turns out
stock needle position
Boyesen Reeds
FMF Fatty
Snorkle removed. I will be reinstalling the snorkle and cutting two 1" holes with Univents on the side.

Plug check shows a nice tan after a full run throttle chop/engine stop. I might have to tweak the settings a little when the temp goes up to 15 to 30 degrees C in the summer.

This bike has way more jam than in stock form. It is so fun to burn around on now.

Cheers !!

SB

 

[helio lucas]

maybe your bog come from the modifications on airbox and not from the new pipe...

there was here a tread about performance on pw 80´s
i´ll try to find it
good luck with your little devil...

here it is
http://www.dirtrider.net/forums3/showthread.php?t=83770&highlight=pw80

 

[summitboy]

I got rid of the bog. If i go back down on the pilot i would get the bog with or without the snorkel removed. She works like it was meant to now ! Thanks for the link.