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Discussion Starter #1
Greetings,

Recently purchased '95 900SS/SP, 5,500 miles, unknown jet kit (I have a work order from the prior owner that indicates a jet kit was installed, but it doesn't state the type) and carbon fiber cans. Factory airbox lid and filter.

Bike seems to be running very rich (heavy fuel odor, white smoke, balky, etc.). I'm wet behind the ears when it comes to these Mikuni's, so how do you determine if this is a mixture or jetting issue?

Thanks!
 

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Probably should start by checking the air filter and plugs. Black plugs indicate rich fuel mix, light color (white, faint brown) indicate a lean mix. Is there a fuel pump and does it have a return line to the tank? If so, check to line to see if its kinked or resticting flow, that could cause high fuel pressure to the carbs, simulating an rich mixture.
 

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Discussion Starter #3
Thanks......I'll check the status of the plugs first....I see no evidence of a restriction in any of the fuel lines.....
 

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The only real way to confirm the status of the carb jetting is to disasemble and read the jet id numbers and inspect the needles and needle jets, and float height.

The needle jets have a dendency to wear early on the mukinis giving a rich mixture over the whole throttle range off idle.

If it runs rich to the point of putting out white smoke and heavy carbon deposits on plug and exhaust then altering the mixture screws won't fix the proplem. I'd suggest stripping the carbs, inspecting the needle, needle jet, main jets, and general clean. Re-set teh needle height, fuel float height and mixture screw setting. Without proper documentation and help this would be difficult if your not familiar.

Regards,
 

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Discussion Starter #5
Thanks for the input......I know absolutely nothing about these Mikuni carbs, so I'd have to rely on someone to do the work......As with my car, finding someone qualified is 95% of the battle......

Can I pull the carbs, and have them serviced separately? Can they be adjusted close enough so that only minor adjustments are necessary once they're reinstalled? I'm fine doing the R&R, but the rebuild part is out of my league....
 

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You can basically set them up off the bike, but need final adjustment of mixture screws and balance of throttle bodies on the engine with it running.
 

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Discussion Starter #7
Excellent.......Thanks again......

Now, tell me about these Keihein FCR's?

Can you use the factory airbox set-up?

Are they worth the upgrade expense?
 

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Carrera85 said:
Excellent.......Thanks again......

Now, tell me about these Keihein FCR's?

Can you use the factory airbox set-up?

Are they worth the upgrade expense?
Yes.
Yes.
Hell yes!

Seriously, the FCR's are great bang for buck, and no down side.
 

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jwsparkes said:
The only real way to confirm the status of the carb jetting is to disasemble and read the jet id numbers and inspect the needles and needle jets, and float height.
So uhh.. how hard is that? I know next to nothing about carbs, but have a little bit of fuel injection experience. I am half-way mechanically experienced, but a little worried about tinkering with teh old-school ;)
 
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