372xp converted to..........

[Huntaholic]

Ok, after using a 390xp, the 372 just wont cut it anymore, pardon the pun! I would like to pick the brains of those who have come before me and see what they have to say. Here is the question: What can I expect if I put the OEM 75 cc P&C part number 544 25 43 -02, and use a 390xp intake and carb? I sent mastermind a PM asking what he could do to get a 372 close to a 390 performance wise, but he doesn't build used saws anymore and I hate to drop the coin on all new and still not get where I want to be. Any thoughts? The only "used" parts in this potential build will be the crankcase. Crank, bearings, seals, P&C, intake, etc... will all be new.

 

[grack]

If oe slap a popup 268 piston in it
Muff modded
Is my favorite combo on 371/372
I run popup 272s on the bigbores

 

[Huntaholic]

Hmmm. Ok, let me get all this straight: The saw Im playing with is just that, something to play with to see what I can do without having to buy a new one and send it off to be modded. Right now its got a fresh new set of OEM bearings and seals in the bottom end, running an AM 76cc top end and a new OEM walbro 372 carb. I have on order a new OEM 75cc P&C, a 390 intake and Ive got a good OEM 390 carb. Muffler hasn't been modded but it is the farmertec replacement which is just a hollow can with a single round exhaust opening.
I also have a VERY GOOD oem 372 P&C in my parts bin to play with. So what youre saying is I would see more gains by putting a pop up 268 piston in the OEM 372 cylinder, or put a pop up 272 piston in the OEM 75cc cylinder?
As a professional timber cutter, what Im wanting is more torque in the cut. Chain speed the 372 already has over a 390xp, where the 390xp shines is in torque and torque rules when it comes to falling trees. Im not cutting firewood or 18" rounds. In fact 18" is the bottom end of my cutting plan.

 

[SawTroll]

Be aware that the 75cc cylinder is much more in need of port work than the original 71cc one, as the porting isn't originally meant for chainsaw use (it is a power cutter top-end originally). A lot more metal needs to be removed.
Also, a 372 XT carb is larger (venturi) than any 390 carb, and likely a better option. I no longer recall what else is needed to make it work with either of the non-XT 372 top ends (or the 390?) though.
Carb verturies mostly can be opened up, but it takes some knowledge to do it right, without destroying the carb.

 

[sunfish]

Porting the oem 50mm top end will get you the best gains. Randy is good, but isn't the only saw builder out there. The 75cc (52mm) top end isn't going to get you anything if left stock. What grack said it interesting about a 268 pop up, cause the higher comp should boost torque.

 

[Deleted member 117362]

Sell your 372 and buy a 390, cheapest way to go with best results.

 

[Huntaholic]

Sell your 372 and buy a 390, cheapest way to go with best results.

Ive already got 2 390xp saws, plus a stihl 660. All 3 of them are TREE MONSTERS when it comes to cutting timber. What Im playing around hoping to do is get something half way comparable in a lighter saw. Im not sure how familiar you are with my part of TN, but a couple pounds makes a world of difference when youre carrying it in these hills.

 

[ammoaddict]

Ok, after using a 390xp, the 372 just wont cut it anymore, pardon the pun! I would like to pick the brains of those who have come before me and see what they have to say. Here is the question: What can I expect if I put the OEM 75 cc P&C part number 544 25 43 -02, and use a 390xp intake and carb? I sent mastermind a PM asking what he could do to get a 372 close to a 390 performance wise, but he doesn't build used saws anymore and I hate to drop the coin on all new and still not get where I want to be. Any thoughts? The only "used" parts in this potential build will be the crankcase. Crank, bearings, seals, P&C, intake, etc... will all be new.

You may want to check with wicked saw works (also in TN). He had an exchange program where you could send him your OEM cylinder and he would send you back a ported one. Not sure if he is still doing it or not, but worth checking because shipping is alot cheaper and turn around time is faster

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