051-076

[FrankHgh]

can a piston and cylinder from a 076 interchange with piston and cylinder on a 051?
I have both.
What i'd like to do is put the piston assm from the 076 on a 051,,could it be done?

 

[Phil_C]

In the IPL's I have for both saws they appear to have the same shaped crankcase but the part number is different. They have the same size bearings, seals and the same crankshaft but the 076 has a manual oiler inside the oil tank. I know some had the oil cap on the top but the IPL's show both on the side. The 076 cylinder is bolted on with long M6 studs and nuts whereas the 051 cylinder uses M5 SHCS.(Socket Head Cap Screws) so you would have to change them.
From what I can see in the IPL it would be possible.

Regards

Phil

 

[leeha]

I'm not sure what has to be done.
Bit this swap has been done many times.
I believe " HOSS " has done a few. Maybe
he will chime in.



Lee

 

[FrankHgh]

thanks guys

although a simply parts exchange the 051 is a cool saw, i really look forward and i'm sure this exchange has been done

 

[ms290]

i say just try it. the worst thing to happen is you'll come out with a little more experience.

 

[betterbuilt]

I read somewhere that you should be sure to use the 6mm studs that come with the 076 case. You'll have to make the holes bigger in the 051's case.

Post some pictures.

 

[John Wagstaff]

Hi guys, been a while since I posted, I have been rebuilding my planking mill, this has 2 075av power heads fitted, the first was an easy rebuild just stripped cleaned and fitted new rings, crank seals and carb diaphragms, the 2nd more troublesome as a small m5 nut from the air intake assembly found its way into the piston and bore, this totally wrecked the piston, rings and bore, so had to total strip her down to get all the metal bits out of the crankcase, having reassembled this baby I now have a problem when I pull the starter it snatchers back quite violently. I'm a little unsure if the timing has moved or if I should retro fit a decompression valve, (these I think were never fitted with a decompression valve although there appears to be a stud in the cylinder head) any ideas please.

 

[Phil_C]

Sounds like the flywheel key has sheered off and the flywheel has turned on the crank thus putting the timing out. I have seen it a number of times on the 051 especially if the flywheel is refitted to a dirty or oily crank. Given that a small M5 nut in the system would most likely have caused a very violent stoppage it could have sheered the key. Did you check the key when you stripped the saw?

 

[John Wagstaff]

No not checked that, will strip down the starter side and look.

 

[TPA]

I just rebuilt my 075 with the same result. base gasket delete plus new rings yielded 190 psi. The piston is approx. 4 square inches. This translates to almost 600 lbs of resisting force at peak pressure. Not every pull will be at peak force, and peak force is an instantaneous value at TDC, but this kind of demonstrates why pulling is difficult. I will be installing a decomp valve. Watch ebay, they are hard to find, and harder to get a good price on one.

 

[John Wagstaff]

I thing that a decompression valve might be a good option. I'll also be looking at the flywheel key as well.
I've fount a local supplier that still have these for about £25.00UK. So will order 1 from them.

 

[John Wagstaff]

Hi guys, Stripped down my 075 to have a look at the flywheel key, wasn't sheared as suspected. so needed to investigate further, I have invested in a Stihl test set (cost me £100) but I think it will prove well worth it, I have tested the ignition armature and the readings are as stated in the manual (1 ohm on primary and 8700 ohm on the secondary) so good to go, this is fitted with an electronic switching unit, so no testing needed as the manual stated when I did the spark test. So having cleaned everything and re-assembled her I tried to fire it up, and still have the same problem, that is when I engage the recoil starter it snatches back extremely violently. So guys, has anyone any ideas where to go from here??
I should also say that when I rebuilt the crank and bore assembly I did lightly coat all components with a light grade oil.