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Discussion Starter · #1 ·
First off I want to thank you for taking the time to read this post.
Now into the trouble. I was having a hesitation while at an idle and while accelerating from a stop and while WOT. To fix this I was going to change out the mains to a 130 and pilots to a 40, however the guy a factory pro told me that based on my symptoms changing from a 38 to 40 was all that was required. I also discovered that there was a hole in the air filter, so I changed it out for a set of POD's. While in there I changed the air/fule screws to 2.5 turns. Once back together I tested it and it was wonderful at low speeds, no hesitation while under no load. However now at about 5000 rpm throttle >1/2 open it bogs down and will almost die until I release the throttle. I replaced the plugs with the iridium plugs. I am at the end of my rope here and out of ideas, Iwas hoping that one of the guru's could please help me.
 

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I was having a hesitation while at an idle and while accelerating from a stop and while WOT. To fix this I was going to change out the mains to a 130 and pilots to a 40, however the guy a factory pro told me that based on my symptoms changing from a 38 to 40 was all that was required.
ASSUMING that you have Keihins (since you've provided no useful info) all that's usually required is cleaning the pilot jets. Moving up to #40 pilots will work but you'll foul the plugs in short order and you may develop a small-throttle misfire when the weather gets hot.

If you've got Mikunis then the problem could be worn needle jets, depending on the miles on the bike (again, no useful info provided) or dirty pilot jets, but the Mikunis are much less prone to this than the Keihins.

I also discovered that there was a hole in the air filter, so I changed it out for a set of POD's. While in there I changed the air/fule screws to 2.5 turns. Once back together I tested it and it was wonderful at low speeds, no hesitation while under no load. However now at about 5000 rpm throttle >1/2 open it bogs down and will almost die until I release the throttle. I replaced the plugs with the iridium plugs. I am at the end of my rope here and out of ideas, Iwas hoping that one of the guru's could please help me.
That 5K stall is an indicator of wrong-sized main jets. In your case they're undersize from the change to pod filters, so either replace the stock filter or search the posts here for the correct size range of main jets.

Good luck.

Jim
 

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Discussion Starter · #4 ·
Thank you, I have Keihin carbs. I am not the most able mechnaic out there, more of a computer/electronics guy, but trouble shooting is trouble shooting. How can I tell the difference between to lean and to rich of a mixture?

Respectfully
Paul
 

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It sounds different. A rich mixture makes the exhaust sound kind of dull and 'burbly' while a lean mixture sounds sharp and has a kind of 'crackle' to it.

The trouble is that when your main jets are far out of range, the bike dies too quickly to figure it out.

You'll have to go through the old posts on pod filters and check the 'setups' thread to get to about the right size and go from there.

Be aware that your engine will tolerate a 'too lean' condition much better than a 'too rich' condition. If the mixture is too rich, it pulls too much heat out of the cylinders and the engine looses power very quickly.

Jim
 
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