Pioneer chainsaws

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3/8 68dl .058 yes. It has 8 tooth sprocket. I just order b n c from lol red now

your 8 tooth sprocket is the problem with the 68 DL chain. the saw came standard with a 7 tooth. you will need a longer chain to run a bigger sprocket! you will need to add a DL to you 68 DL chain or run a 69 DL chain with your 8 tooth sprocket. A 70 DL chain may also work, but you will definatly need 69 w/ 8 tooth. it is .75" farther around an 8 tooth sprocket. It is just math, to add an extra tooth to the sprocket you need a chain that has one more drive link and that requires two ( 2 ) more side links to fit in the extra drive link in.

The new chain and bar from Red barn will not work also because of your 8 tooth sprocket. order a 7 tooth sprocket and everything will fit.
 
Tillotson HU carburetor:

I was wondering if there are any carburetor gurus that might be able to help me out with the operation of a Tillotson HU carburetor. It’s currently installed in a P20.

I pulled the carburetor and cleaned it and put a fresh needle,lever gaskets and diaphragms into it.

As usual I pressure tested it to make sure everything thing was as it should be.

Now I have only rebuilt a few barbs but never an HU. So far I’ve had success and have been able to adjust the lever and fix any leaks.

This darn carb has me baffled! When I pressure test it, it won’t hold a darn bit. So I opened the carb and recheck the diaphragms and needle height and everything seems correct.

Hook the hose back on and pump the air in and it still leaks like there’s a whole it the barb or something.

Sure enough I found where it’s leaking but can’t understand how you could avoid this.

The air pushes straight through to the impulse port that attaches to the insulating block . If I cover that hole with a finger , sure enough it holds air. I rechecked the diaphragm to see if one of the check valve flaps was out of place but it looks right to me.....,,

My question (after that looong detailed rant) :

Is this model supposed to work like this? Is it just how the carb pulls fuel and air? The saw starts after about 6 to 9 pulls which seems wrong. About three pulls with trigger lock and prime to get it to cough, then three or more no choke and trigger lock to get it to fire and run. Seems to idle ok and run ok. Maybe a bit on the rich side though....

Any thoughts?
 
Sounds to me you over pressured the pump side of the carb and the diaphragm has moved OR it has a hole in it. How much pressure are you using?
I don’t think I over pressurized it....normal carb tester pressure. 6 to 8 PSI. The pressure tester applies small incremental amounts as you pump it by hand so no big spikes in pressure.
 
I have actually had that exact issue on a Walboro circuit plate type carburetor. This one attached to the the metering lever and seems to seat the needle properly...... very strange. Gonna have to open it again and see if I am missing something stupid.
 
I have actually had that exact issue on a Walboro circuit plate type carburetor. This one attached to the the metering lever and seems to seat the needle properly...... very strange. Gonna have to open it again and see if I am missing something stupid.

When you take it apart again check the pump side diaphragm and gasket for extra holes or pass ways that shouldn't be there. If your kit was a clone kit disguised with the proper printing on the bag to look like an OEM kit it may be wrong parts. If you still have the old Gasket and diaphragm check the new against them to verify. The only way you can lose air into the pulse fitting is from a hole or pass way in the wrong spot. or a hole in the diaphragm in the pump area.
 
Tillotson HU carburetor:

I was wondering if there are any carburetor gurus that might be able to help me out with the operation of a Tillotson HU carburetor. It’s currently installed in a P20.

I pulled the carburetor and cleaned it and put a fresh needle,lever gaskets and diaphragms into it.

As usual I pressure tested it to make sure everything thing was as it should be.

Now I have only rebuilt a few barbs but never an HU. So far I’ve had success and have been able to adjust the lever and fix any leaks.

This darn carb has me baffled! When I pressure test it, it won’t hold a darn bit. So I opened the carb and recheck the diaphragms and needle height and everything seems correct.

Hook the hose back on and pump the air in and it still leaks like there’s a whole it the barb or something.

Sure enough I found where it’s leaking but can’t understand how you could avoid this.

The air pushes straight through to the impulse port that attaches to the insulating block . If I cover that hole with a finger , sure enough it holds air. I rechecked the diaphragm to see if one of the check valve flaps was out of place but it looks right to me.....,,

My question (after that looong detailed rant) :

Is this model supposed to work like this? Is it just how the carb pulls fuel and air? The saw starts after about 6 to 9 pulls which seems wrong. About three pulls with trigger lock and prime to get it to cough, then three or more no choke and trigger lock to get it to fire and run. Seems to idle ok and run ok. Maybe a bit on the rich side though....

Any thoughts?
I have seen kits that have the incorrect pump chamber diaphragm in the kit for that carb, check to make sure the hollow pump chamber is totally sealed by the diaphragm. Even had guys mail me their carbs lately due to this mistake in the kit contents.
 
Good mourning all, there is a nice looking P52 on ebay ending in about 4 hrs, 12:19 EST. It is already above my price point / threshold, so take a look and have at it. A P40 also ends just before The P52.

Remember Lavoy!
Laus Deo,
Ken
 
Got lucky and snagged this one on Friday night. 700D. Has ok compression, and surprisingly, good strong spark (I was expecting the coil to be totally shot, like they usually are). The fuel and oil tanks are spotless inside, it has most of its paint (3 different shades of the same yellow) and only 2 cracked ribs on the starter cover too! It also has pioneer branded chain, and a bar from a much earlier IEL saw.

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Lots of carbon in the exhaust and the top ring doesn't look quite right..... so i'll order some new rings and seals before I try and start it. I can't remember if the cases have to be split to do seals on these or not. It may get the full restoration treatment, but I've got another couple saws that need a lot of work first.
 

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