I have a '97 Magnum 425 that has started acting up for the past two months. It seems to have no power on the high end and only manages to top out at 25 or 30 mph. I changed all the fluids, dismantled and cleaned the carb, new air filter, checked for air leaks on the back side of carb. It has always been very sensitive to air flow (prefilter installed and a K&N air filter) and is currently jetted for around 8,000 feet. Not sure what else to check but it's killing my hunting season pretty quick.

Any help would be appreciated --

Paul

 

its the cam shaft all most positive i had the same problem.

 

Check your clutch first make sure the secondary is working.If that is ok check the valve settings they should both set at .006 while you have the cam cover off be sure to check the cam lobes.

 

Aside from no power, what other symptoms are there? Does it sputter, bog, backfire, hesitate? Does it idle OK? I would probably check the compression.

 

Thanks for all the help -- other symptoms are very slow on the excelleration but won't peak out, idles fine. Revs up good when in neutral but once you put some torque on it, it stops to work well. I replaced the belt not too long ago. I always thought it may be compression or a valve problem but wasn't sure, possibly some type of leak either off the carb or the exhaust side. It doesn't bog down, burn oil or blow smoke. I tried to check the simple things first but after reading the forums about problems with other quads I started to second guess myself.

I would have thought that if the rings were blown it would burn or blow smoke but I'm no expert, for sure. That's why I kind of figured the valve clearance was jacked.

Thanks again -- pvs

 

It realy sounds lie you have a button broke in the secondary clutch!