For those of you with ported 372s

[A.E. Metal Werx]

just ported my 372 and stuck a non-limited coil in it. but am kinda half ass new to tuning by the 4-stroking sound. i always tuned it to 13500 with my tach. i would like to tune it with a tach but dont really know a safe range. i know all ported saws are different but am looking for a good safe number for the R's also what is a safe limit for the 372? so i know to not pass that if i can help it. oh by the way... this saw rips!!

 

[Brad101]

From my experience a ported 372 should be set around 14200-14500 non limited. Kinda depends on the work but should run good in that range "maybe" a little more.

 

[timberwolf]

Could be 13,000 could be 15,000 It's a ported saw so all bets are off, tune by ear, read the plug , time cuts.

Start rich and lean a bit at a time, once you found the sweet spot right near the edge take a step or two back.

 

[funky sawman]

Depends on what kind of oil you use. A mild 372 will handle 14000 all day and I'd say and "woods ported" 372 otta handle 14500 max. I base the figures off experence of cutting timber 6 hrs a day and getting at least two seasons out of the saw. But remember their is many ways to mod a saw so the 4 stroking noise is the best way to tune a saw.

 

[CentaurG2]

I have an old 371 with a non-limited coil. Runs real well at 13800 but it is bone stock. These saw run real strong straight out of the box. Never seen a need to port them or even modify the muffler. Just a sharp chain and the chips will fly.

 

[timberwolf]

LOL, clearly you never tried a ported saw.

 

[rahtreelimbs]

+1

 

[blsnelling]

LOL, clearly you never tried a ported saw.

+1. There is absolutely no way to give you safe number. You will have to start by ear.

 

[056kid]

What does that limited coil cut at? I am wainting for the door bell to ring any minute(probably be a day or three) here then i can get the non limited coul and pro saftey wrap bar on there. I am just under the limit and the thing is running way rich with just some opening of the intake & ex.

 

[J.Walker]

They checked my PP372XPW at Spikes GTG. I was running another thousand RPM higher than a stock XPW.
A while back I had the fuel line replaced in my PP357. Got the saw back and it was running slow. I asked the dealer if he had adjusted the saw. He says ya it was running a little fast! I said put it back to were it was, I like it that way!
I was all set the other week to buy a 2171 and put a 75cc P/C in it. But another 262 came along and I could'nt resist it. So that 2171XPW is still watting to be born.

 

[CentaurG2]

LOL, clearly you never tried a ported saw.

I have a Univent. Its kinda ported but still runs toot sweet. Currently pulling a 28” bar with skip chain through hardwood no problem and its not screaming like a 220swift. Running at 13K till it gets a few more tanks through it.

 

[timberwolf]

You bring up a good point there, running a 28 inch bar on 372 is going to affect the WOT RPM as far as tuning it will take a leaner setting with a long bar to achieve the same max RPM. that ends up giving you less safety factor than a short bar tuned to the same RPM, problem is compounded too in a couple ways, longer bar you expect more load on the engine, more load is less RPM and more heat. On top of that less RPM is also less fan to move that heat away.

Stay in factory reccomendations don't mess with the saw and it's pretty much a no brainer, follow what the book says go outside factory specs and you need to think it through.

 

[Tree Sling'r]

Just run it, tune it, run it, tune it. When your happy and the saw sounds happy tach it. Use it as reference. More than likley your exhaust is too high, not bagging, just plain and simple, never met anyone who did a perfect port job their first time.
With that being said, don't blow your saw up.

 

[rahtreelimbs]

What does that limited coil cut at? I am wainting for the door bell to ring any minute(probably be a day or three) here then i can get the non limited coul and pro saftey wrap bar on there. I am just under the limit and the thing is running way rich with just some opening of the intake & ex.

Doesn't really matter where your coil cuts out if you tune the saw in the cut. Your saw will never hit that if you are cutting decent size wood!

 

[timberwolf]

Here is my 365 based off a Baileys 372 BB jug and aftermarket piston

http://www.youtube.com/watch?v=sIbwQK_jr-I

Any guesses on RPM?

 

[SWE#Kipp]

18k !?

 

[timberwolf]

Pretty close, it will do it, actually maxed the tach out at 19,000 when I had a crack in a pulse line but I feel a little better keeping in down about 17,500.

A high ported 372 work saw with some carb work will go a little over 15,000, BBs always seem to be a little lower RPM wise than stock, more piston mass and a little move gas volume to pull through intake and push out exhaust.

 

[056kid]

Doesn't really matter where your coil cuts out if you tune the saw in the cut. Your saw will never hit that if you are cutting decent size wood!

true. but i do as tree slinger said, cut tune cut tune... I keep my trusty stihl screwdriver in my mouth, from tree to tree adjusting as needed. it dosent take long to find out where a saw is happiest.

So i other words i tune by ear and smell. if i get a hold of one of thoes little tachs, it's going on the trike!!








When does it cut??

 

[A.E. Metal Werx]

could some one please post a good link with a saw 4-stroking. so i cam make sure its doing what i think it is.. and i didnt really touch the top of the exhaust port other then to polish it.

 

[rmh3481]

madsens carb tuning link

Here try this;
http://web.archive.org/web/20051228040631/www.madsens1.com/sawtune.htm

I believe it has some audio files that you can listen to.

Best wishes,
Bob