Carbed 08 WR falls on its face

[M5-]

So here's the problem. My buddy did a bunch of changes to his bike this winter and the results are not good. I made a carb heater for his Keinen FCR carb which he installed. Problem is when you try to pull WOT the bike falls flat on its face. Its hard to tell if its lean popping or super fat, sounds lean to me. Plug comes out looking pretty normal. He swapped out the main jet with everything from 162 to 180 with no real difference. The heaters ID is the same as the carb throat and is bolted up to a 2.5" tube and pod style filter so its getting lots of air IMO. Here's the difference, the heater makes no provisions for the air jets on the bottom of the FCR carb. On the stock airbox there is a small baffle around the bleeds where they are fully exposed on the heater setup. Could this be the issue?

Ideas.


Thx M5

 

[oldsno]

My cr bogged like that, it was the float level. Takes lots of fuel as you know to pull a track....

 

[74bronco2]

How long is your 2.5 tube to your pod? To long of a tube made my fcr bog like that.

 

[summitboy]

Check float level and check for water. On the trail Paul ? If its only in the snow then i call ice !

 

[M5-]

Happens everywhere, carb heater is putting lots of heat into the carb so pretty certain its not ice. Right outta the heated trailer it runs like crap.

M5

 

[Grr]

Sounds like he forgot to put something back in, leak jet maybe? On my PWK it has the extra booster jet and i never even thought of it. Jetted it like my PJ and it wouldn't even run just like you describe. Great up to about 1/4 throttle then sputtering and nothing. Soldered the 50 power jet closed and its perfect.

 

[kell8071]

Rag in the airbox or bad sparkplug that misfires at high rpm?

It could get a little wild but what about trying to rev it out with the track off the ground? A little more loading then being in neutral but still not heavily loaded. Might help diagnose the source?

Kell

 

[CATSLEDMAN1]

not sure

after Todd rebuilt his 450 suzuki last week, first run on Sunday his bike doing the same on 07 with carb. More gas with fuel screw helped, raised needle and it helped, but feels like it needs bigger main and less fuel screw, we shall see, but your bike sounds lean. I ran a wr for 4 years, in the end I replaced the stock carb with 4 stroke Lectron, cured a lot of wr issues like hard starting on the button and strong mid range pull with better Lectron jetting.