Carb issues, help needed

[BGE541]

Hello So I started another Husky 350 build and the saw runs well, but I'm having issues tuning it now. Saw it muffler modded, ported, all new dirko/sealed up well but when I run it I can get it to 4 stroke at 12.7k yet if o keep it WOT I hear it continue to rev up to 14.2k where it holds steady and doesn't 4 stroke yet still runs well. It slowly (maybe a second) gets up the 14.2k but I'm guessing it's a carb/metering lever issue? Thanks for any and all advice. Oh pulled the muffler and it looks great, no build up just a little light tan, no caebo and nice cross hatching. Unlimited coil fwiw.

Thanks all.

 

[Redfin]

Lean out the L a tad. Should help with delay. Why do you have the H set so high if its not stroking?

 

[Mark71gtx]

Did you vac and pressure test it?

 

[BGE541]

Lean out the L a tad. Should help with delay. Why do you have the H set so high if its not stroking?

I should rephrase their is no delay in revving it revs very fast but rather a delay in WOT from when it goes 12.7k to 14.2k... But then hold steady with no 4 stroke. This is a play/test saw it held 14.2 k for 15 seconds then I got it and wood and cuts great...

I haven't pressure or vacuumed tested because it was all new or replaced and I need to get the set up for that still.

 

[Mark71gtx]

You do not need anything super special to vac and pressure test other than a mighty vac, which should be your next purchase if you don't have one. Get an old inner tube and cut it to make block offs for the back side of the carb and for the muffler. Put the block offs in place and tighten the screws back down. Unhook the impulse line from the carb and hook the mighty vac up to it. That will test the whole saw. If it holds, you have another problem. If it don't, put it on pressure instead of vacuum and spray it with soapy water. You will find your leak. Just because it's new or freshly redone does not mean it will not have a leak. Sometimes there is a pinhole in the intake boot that you can't see. Sometimes the metal portion of the crank seals doesn't seal properly (I coat all of my seal edges with sealant now because of that). I hope you find your problem.

 

[huskihl]

Yep. That's an air leak

 

[BGE541]

Thanks I'm gonna figure out the pressure/vacuum test.

 

[Mark71gtx]

If you don't have a Mighty Vac, there is likely a member nearby who does that can probably help you out. If you plan to tinker with saws, you should really look into getting one. It is the best diagnostic tool you can get for a saw in my opinion.

 

[Redfin]

I should rephrase their is no delay in revving it revs very fast but rather a delay in WOT from when it goes 12.7k to 14.2k... But then hold steady with no 4 stroke. This is a play/test saw it held 14.2 k for 15 seconds then I got it and wood and cuts great...

I haven't pressure or vacuumed tested because it was all new or replaced and I need to get the set up for that still.

My 44 did the same. Spooled quick then paused before reaching max. Lean the low side a smidge.

 

[BGE541]

Thanks for the replies. I don't know any members around me here in WA but I may have to invest it a set up for pressure testing now

 

[MustangMike]

The first base gasket delete I did failed, I did not sand and clean the surfaces with brake cleaner. Just scraped it and wiped it clean like I used to do on the cars. It was not good enough. I realized something was wrong when my idle started to deteriorate.

 

[BGE541]

Mityvac 8500 ordered thanks rattler

 

[Chainsaw Jim]

Air leak or stiff metering diaphragm.

 

[BGE541]

Ok folks we have a solution! Got the new mityvac fired up... A spark plug leak but more importantly a leak at the top of the intake mount/clamp. So ordered a 346xp one with nonplastic clamp BS. Surprisingly no other leaks. Will reengage when I get it back together thanks all!

 

[Mark71gtx]

That mityvac will save you a bunch of money and time if you keep tinkering with saws...

 

[BGE541]

Hopes so seems to work well so far. Thanks again will update when I get the parts!

 

[1990Husky262]

do yourself a favor and make sure you retest after you install the new intake clamp. Sometimes you can have more then one leak but they cant so up till you fix the bigger leak. just remember a pressure/ vacuum test is a quick and simple way to no for sure everything is sealed up tight and your not going to have a melt down do to lean mixture from an air leak.