Bad Decomp on 372xp and Tuning Questions

[802climber]

Been running a lower hours 372xp, bought a couple years ago, stock for now...

A couple quick questions.

As of the other day, the decomp valve will not pop back out after the saw starts, I have to pull it back out manually.
Does this mean it is leaking also, or just defective?
The saw starts easily and runs/idles well.

Also, I tach my saws every day after blowing out the air filter with compressed air and I have had to turn the H screw all the way counterclockwise to the limiter to get this 372 to stay below 13500. It is traveling between about 13300 and 13480. Tach is a stihl edt8.

I would rather have it a little rich than occasionally jumping a hair above 13500 at WOT like it was doing.

Something weird...This tach only works on my big saws if I clip the lead to the spark plug wire.

But it works on my small saws wirelessly......

Thanks for any advice!

 

[w8ye]

The difference in the way the tach works may possibly be related to using a "R" plug in the the saws were it doesn't work wireless?

The decompression is probably fouled with carbon?

Time to cut the limiters off the needles on the carb?

 

[802climber]

All my Husky/Jred take the same plug.

I think they make special screwdrivers "for dealers" that allow the screws to be turned past the limiters. Because on a newer saw, the saw will not hold a tune with the limiters ripped off, IIRC...

I just thought on a stock saw I shouldn't be hitting the limiter. What if I had to richen the saw a little more? Then again I am running 93 octane, husky xp oil, and a clean air filter.

I guess I should hold off for a bit on opening up the muffler, because I cannot richen the High screw anymore than it already is. A muffler mod will lean out the saw right? Or do I have it backwards?

 

[7hpjim]

Pull the decomp and clean it w/carb cleaner, and de-epa the carb so you can tune it properly, limiters restrict how much fuel/air the engine gets which is affected by atmospheric conditions, temperature, altitude and so on, so if you want the most out of the saw make the carb fully adjustable and keep it tuned.

 

[rupedoggy]

Sometimes the decomp gets bent. If it takes a blow from the side the shaft gets bent and won't release. Check visually.

 

[blsnelling]

All my Husky/Jred take the same plug.

I think they make special screwdrivers "for dealers" that allow the screws to be turned past the limiters. Because on a newer saw, the saw will not hold a tune with the limiters ripped off, IIRC...

I just thought on a stock saw I shouldn't be hitting the limiter. What if I had to richen the saw a little more? Then again I am running 93 octane, husky xp oil, and a clean air filter.

I guess I should hold off for a bit on opening up the muffler, because I cannot richen the High screw anymore than it already is. A muffler mod will lean out the saw right? Or do I have it backwards?

No special screwdriver for your saw. You have to trim the limiting tabs off the caps. I leave the caps on, but they're not required on your saw. 372 carbs still have springs under the needles. You must be thinking of Stihl saws. They no longer have springs under the needles. Sounds like your saw is fine. I wouldn't stress over it.

 

[Johny Utah]

All my Husky/Jred take the same plug.

I think they make special screwdrivers "for dealers" that allow the screws to be turned past the limiters. Because on a newer saw, the saw will not hold a tune with the limiters ripped off, IIRC...

I just thought on a stock saw I shouldn't be hitting the limiter. What if I had to richen the saw a little more? Then again I am running 93 octane, husky xp oil, and a clean air filter.

I guess I should hold off for a bit on opening up the muffler, because I cannot richen the High screw anymore than it already is. A muffler mod will lean out the saw right? Or do I have it backwards?

You can use a deck screw to remove the limiter caps. If you just grind off the stop on the cap you can put it back on and adjust it without it stopping at the factory limit.