Quick question- pilot jet range?

[ClutchinChrisG]

I've got the Slant-Sudco-Downdraft-whatever FCR on my '00 Z.  

I am just wondering what pilot jets get run in the Slant FCR. The previous owner said it ran perfect, back in 2004 before he left it sit till now.  I know first hand that he isn't the most anal mechanic out there either, so his perfect could have been not so perfect.

I got it running pretty good but with low end issues.  It has a NEW 45 size pilot jet in it, the same as it had previously, but I am experiencing lots of noisy backfiring on decel and a hanging idle.  The idle is obnoxiously high when setting the idle speed, then at one point it will drop to a very slow and unreliable CHUG-CHUG. From this slow point there is a sort of phantom throttle from there till an 1/8 twist of the throttle where it will be obnoxiously high again. I'm assuming this is also a lean low end characteristic.

To my original question, does anybody actually run a larger than 45 pilot jet? It seems that nobody does and if so then maybe my problem isn't the pilot jet size but my carb is still crudded up.

I ordered a 48 and a 50 from Jets R Us.  I also plan on removing the CE when installing the next size up jet.

BTW, I've got a corked up Big Gun on it, what size Main jet is recommended with that?  It had a 165 in it when I got the bike but that seemed a little big. I put a 162 in it...

It's my first bike by the way and it is a blast! I'm very excited to be a member of the dual-sporting brotherhood! 

 

[ClutchinChrisG]

And also, I have the RD flex fuel screw, it seems to have no effect on the idle no matter how far out or in I turn it. I can turn it out till it just about comes out and in till it seats, nothin' happens. 

[bumtarder]

I run a 42 pilot jet and a 100 pilot air jet in my 39fcr with a stock SM motor and it works just fine.My '02 E bike has a 45pj as stock and runs good with the coast enrichener left in.

 

Perhaps there is an air leak in the carb boots.Maybe the fuel screw isn't assembled correctly or there is an extra o-ring stuck in the seat or the seat is damaged or badly scored.

[ClutchinChrisG]

My bike is the E model.

The fuel screw is assembled correctly I'm pretty sure, spring, washer, o ring, in that order.

I'm starting to think that the gaskets and o rings in the carb midbody might be shredding. But I'll put in a bigger pilot jet and see if that fixes it.

Maybe the carb boot has an airleak, I haven't checked for it.