1998 Tigershark TS640L.. Falls flat on it's face...

merkurfan

Petty Officer 3rd Class
Joined
Jul 31, 2012
Messages
80
I have been through this things carb twice. Compression is 145/150. I found a bad reed on Sunday (cracked, did not come apart) and thought AHH HA! FIXED! but no... it's not.

This thing has never really idled right but it seems to idle ok for a 2 cylinder. When you snap the throttle it just dies. If you nurse it a bit it will pickup RPM. choke does not seem to help. Fuel filter is always full (new) and if you pull the return line off even as it's dying there is a trickle coming out.

Just put fresh plugs in it, there is no high speed mixture (fixed with a jet) and fiddling with the low speed does not change anything.

I am wondering if it's me (assembled the carb wrong? used photo in manual for gasket placement) or maybe the needle/seat as I did not replace those when I rebuilt the carb. I did dip it and blow all all the passages.

It's a mikuni 38mm carb on a suzuki twin engine.
 

BlueFishCrisis

Petty Officer 3rd Class
Joined
Sep 7, 2010
Messages
96
Re: 1998 Tigershark TS640L.. Falls flat on it's face...

Did you pull and check / clean the low speed jets? Are the needles and jets set to factory specifications? It is the low speed section of the carbs that controls your "hole shot", so you should focus there. If choke doesn't help, they are probably seeing an over rich condition on the low speed section.
 

merkurfan

Petty Officer 3rd Class
Joined
Jul 31, 2012
Messages
80
Re: 1998 Tigershark TS640L.. Falls flat on it's face...

Did you pull and check / clean the low speed jets? Are the needles and jets set to factory specifications? It is the low speed section of the carbs that controls your "hole shot", so you should focus there. If choke doesn't help, they are probably seeing an over rich condition on the low speed section.

Yes, low speed jet is clean and the screw is set at 7/8ths.

I am wondering if I have a seal leak or something that is causing it.
 

merkurfan

Petty Officer 3rd Class
Joined
Jul 31, 2012
Messages
80
Re: 1998 Tigershark TS640L.. Falls flat on it's face...

Replaced the needle and seat. Runs much better but still has a bit of a low RPM stutter. But so have all the rest of the 640 sharks I've heard lately.
 
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