335 xpt won't rev

[plumech]

As i have been reading, I am not alone in having problems with this saw. I have a 99 335xpt that starts and idles fine but when you accelerate it just bogs and won't rev. I took the carb apart and replaced the diaphragms and re assembled and still nothing. I tried different gas, checked the fuel line, replaced the plug and yet, still no revving up! My next step is to totally replace the carb but I would like some other opinions as I am a heavy equipment guy and not up on these 2 strokes. Any ideas before I drop $50 on a carb or should I write it off and buy new. thanks in advance.

 

[pgg]

Fuel starvation, low jet too lean, high jet too lean, gauze fuel filter in the carb grunged up, if hidden pinholes in the fuel line the saw'll run fine till it's warmed up then starve, but tweak the jets for some sort of response anyway..

 

[plumech]

Carb fuel filter?

Gauze fuel filter in the carb, I am not familiar with that part. Is it hidden some where in the carb?

 

[kevlar]

plugged muffler screen.

 

[Lakeside53]

Gauze fuel filter in the carb, I am not familiar with that part. Is it hidden some where in the carb?

Yes, it on the pump side. Look for a hole about 1/4inch diamerter with wire mesh in it. If you used the useless zama fuel filters for more then a year, you can be sure it's partially blocked.


As mentioned above, fuel starvation can be because of many causes. I'd check the obvious then perform a full pressure/vac test to eliminate crankcase leaks. If you crankscase is leaking (seals, gaskets etc) you won't be able to pump gas. Fuel vapor pressure can load the carb enough to get it idleing, but not to keep it running.



Before you buy a carb... try to borrow one from another saw.

 

[PES+]

Check the Achilles heel

The biggest problem on these Huskys and Jred top handles is the impulse line they work loose and can act as you describe.

The fuel lines can also loosen and pull air

It is very difficult to attempt to clamp the line and many people use sealant to keep the impulse and fuel lines in place and keep them from leaking.

There are two or three different case set ups for this line and you need to order the correct type of lines for the case style.

Or it may be Zama's fault.........................

 

[plumech]

Fixed!!!

Kevlar is the winner!! It was a plugged muffler screen!!! Thank you to everybody for there time and suggestions. This saw has "never" run this good. I am so happy I didn't by a carb... Thanks again, Erin

 

[pbtree]

Glad you figured it out - and welcome to the site!

 

[kevlar]

it seems the smaller saws plug up,forever cleaning or chucking screens.Glad you got it working!