1998 LT250 fuel issues

[gamedog53]

Ok need some help.  I have a 1998 Suzuki LT250 atv.  It recently started to have issues.  It starts fine and idles great.  The problem is when you attempt to give it gas it bogs down and will not gain any rpms.  Kicker is that if you shut it off and restart it, it will rev up for a second or two and then starts to bog down again.  I have drained the tank, replaced with new fuel, changed the spark plug and finally rebuilt the carburetor.  It starts easily and idles great but still I can not rev the engine up.  I pulled the fuel shut off valve and checked the vacuum line that goes to the carburetor, which seems to be clear.  My question is does the diaphragm on the back side of the fuel shut off go bad?  If so can I replace just the diaphragm or do I need to replace the whole valve assembly?  If so where is a good place to get the parts?

Starting to get frustrated with this issue.  I have owned the machine from day 1 and it has not given me any issues other than this.  Any help is greatly appreciated.  

 

[davefrombc]

I  did a search  on your  quad  to  find out  what  the  diaphragm  on the fuel  valve was all  about. .Found  out it  is  for an  automatic fuel  shut  off and  seems to be  problematic.  Check this thread  I  found if  your  valve  has that  feature .. Says  you  can  block the  vacuum  lines  and run the  quad with the  valve  in the  Pri  position.

http://www.suzukiatvforums.com/forums/repair-maintenance/3970-vacuum-operated-fuel-tank-valve-petcock.html

[gamedog53]

Davefrombc thanks a bunch.  I'll give that a shot in the morning.  

[gamedog53]

Well just a quick update.  The vacuum line didn't solve my problem.  It was suggested that when it starts to bog down turn the headlights on.  Well that seemed to help so possibly the voltage regulator is bad.   

[swshinaver]

Gamedog did you ever figure out this issue? I have a 98 250 Quadrunner That's acting the same way sort of. First Suzuki and I'm stumped.
Picked this thing up for the kids to ride thinking it was an easy fix. The petcock was shot and the crankcase was filled with fuel. Installed a new petcock and changed the oil and cleaned the carb. It starts and idles high with the headlight on. Turn the headlight off and the idle lowers and idles very rough. Either way it will not take throttle. When I give it throttle it falls flat on it's face. Any ideas?

[gamedog53]

Yes I did get it resolved.  It turned out to be the voltage regulator.  Problem is you can see it and touch it but it turned into a 3+ hour job to get the front rack, front cowl, inner fenders and speedometer off and reinstalled.  Since it was so old I had to drill out 2 or 3 of the screws.   Dealers wanted $140-190 for the part.  I ended up buying mine off Amazon.   

 

[swshinaver]

Thank you sir.

[gamedog53]

Your welcome, if you have to buy one look at Amazon.  Mine was $18.85 and identical to the one I took off.  Good luck

[swshinaver]

Just thought i'd update. Voltage regulator did the trick. Quad is up and running.