What else besides BK mod?

5 replies to this topic
  • bbeakley

Posted April 08, 2002 - 09:51 PM


I've got a 2000 426 that I've done the BK mod to but I've still got a bog at the bottom. I was wondering what other things can contribute to this problem that maybe I haven't looked at yet? So far I've cleaned out the carb passages (although not with compressed air, but I did recently buy a compressor and will do that again), I've oiled my filters conservatively and let them sit out overnight before installation, and I've set the BK mod and pump timing according to the BKMs listed on this site.

I suspect it's either insufficiently cleaned passages in the carb or incorrect jetting, I just need some ideas.

  • John_Lorenz

Posted April 08, 2002 - 10:01 AM


What jetting have you done, and when was the last time you cleaned the Carb and Filter...

List of items
1: Inline Fuel Filter
2: spic and span carb
3: Spic and span Filter
4: Jetting

  • skthom2320

Posted April 08, 2002 - 10:39 AM


I had the same thing recently but never encountered the dreaded bog before.

I cleaned the carb real nice.
I was careful with the air filter oil.
I adjusted fuel screw.
I leaned needle (put clip one position higher).

All gone!

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  • bbeakley

Posted April 08, 2002 - 03:36 PM


I was just running on a fresh air filter, but that was following two runs with my new NoToil filter that I over-oiled. I had the bog prior to all of this though. While I'm dis-assembling the radiator to get fixed I'll whup the carb out and clean her up real good (now that I have compressed air!!).

As for jetting, I'm at around 5000' and temps are in the 60's (god I love spring!). I have the FMF powercore IV pipe and run it with 162mj and 45pj. I get some popping at the end of long decels. I haven't done a plug check recently, but mostly cuz that's for main jet checks and I think this is related to pilot jetting. Last I checked the fuel screw is about 1.75-2.0 turns out. Needle is still in stock position.

  • BK

Posted April 08, 2002 - 03:57 PM


Just a suggestion... Try a new accel pump diaphragm. Sometimes they get old and loose their strength.


  • moorespeed426

Posted April 10, 2002 - 08:46 PM


adjust the pump timing with the engine running like shawn mc suggests and it well take care of the bog.

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