Performance questions

[Mainemechanic]

I have a poulan 2075 type 5 36cc saw that was given to me. It runs great but lacks power which I totally expected out of a 36cc poulan. Had a 16 inch Oregon bar on it but it was slightly tweaked and was getting hot and cutting crooked so I put a craftsman 16" bar I had on it and swapped out the worn dummy chain for one that will grab a little wood. So I planned to just run it but then the years worth of oily sawdust that built up next to the jug in the cracks started smoking and smoldering inside my saw after I cut with it for about an hour. So now I find myself with it completely disassembled just to clean under the engine so I thought what the hell, may as well see what's up inside this 15 year old cylinder, and that led to the discovery of some pretty poor porting and such from the factory. I already modded my muffler (removed baffle and screen as I only cut on my property, opened up one of the two tiny factory exit ports, and drilled 3, 1/4" holes in the front of the muffler) and started a port and polish. I was thinking of buying an oversize carb, and I'm not sure what else I can do for more power. I read somewhere, probably here, that some of the bigger 42cc poulan saws share engine parts with other brand saws and because of that you can get a dual ring piston that fits? My piston could stand to be changed, it would keep running but it shows some signs of heat stress.

So my questions are:

1. How big can I make my ports before I stop seeing gains or start seeing problems? ( I know all about free porting and have plenty of room before I'm playing with that fire)

2.What's the best side of each port to take down?

3. What would be a good oversized carb to purchase that would fit my saw? I suspect this would be my biggest power adder, What can I realistically expect? I'd guess more mid range torque which is what I need.

4.Is a double ring piston available and is it worth having one in terms of power or reliability?

5.Is there smaller sprockets available on the market to help it feel a little more torquey?

6.When I disassembled my saw there was no base gasket, only a small amount of sealer of some sort, did this come from the factory this way? The friend I got it from said he bought it brand new in 02 and has never put anything besides fuel and oil in it.

7.Where can I get a detailed and reliable parts manual for my saw?

8.What other things do people do to their saws for a little more power?

I have alot of mechanical experience and a desire to tinker and build things but not to much money at 23 with two kids, one on the way, and my own house, but compared to jeeps, turbo cars and motorcycles, saws are damn cheap to play with. Also I know for what I could end up with in this saw I could buy a brand new poulan the same size, I seen one at Walmart the other day for $109.99, but I sure as hell couldn't say I built it!

Any help much appreciated! Thanks everyone.

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[s sidewall]

The white stuff at the lower half is gas/oil proof rtv sealant. Don't know if you are gonna get a lot of performance out of the saw, setting the carb after that muffler mode will be a must.

Steve

 

[Mainemechanic]

The white stuff at the lower half is gas/oil proof rtv sealant. Don't know if you are gonna get a lot of performance out of the saw, setting the carb after that muffler mode will be a must.

Steve

It's not so much performance I want so much as a workable amount of power to cut my firewood. And yes I am aware I need to adjust for the muffler mod as well as the port job I'm doing to compensate for the increased air flow. Thanks

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[Del_]

I like the craftsman bars.

 

[Mainemechanic]

I like the craftsman bars.

This one has no nose sprocket? Never seen it before kinda gets hot right at the tip but it's tougher than the Oregon

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[s sidewall]

Don't know anything about porting but I hear the guys talking about taking some off at the top of the port and widening the sides some and slightly advancing the timing, but thats on a saw with a flywheel key.

Steve

 

[s sidewall]

Another fellow Georgian. [emoji106]

Steve

 

[Mainemechanic]

Another fellow Georgian. [emoji106]

Steve

Haha me? I'm from Maine.

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[s sidewall]

Del_, that whom I was saying.

Steve

 

[schmauster]

I went through the same saw, poulan woodshark 1950. Putting it together out of two donor saws. I did some porting to practice. I left that metal sleeve in the exhaust port but ported the exhaust window a lot to get them to flow smoothly.

I now cant get it to full throttle due to crankcase leaks or needing a larger main jet. (ported the carb a little too)

 

[Mainemechanic]

I went through the same saw, poulan woodshark 1950. Putting it together out of two donor saws. I did some porting to practice. I left that metal sleeve in the exhaust port but ported the exhaust window a lot to get them to flow smoothly.

I now cant get it to full throttle due to crankcase leaks or needing a larger main jet. (ported the carb a little too)

You only did the exhaust port on the cylinder and the carb? Or intake port to? Did your saw(s) have a plastic piece that the carb mounts on? Mine does, I ported that significantly, as well as what I would call mild port on the cylinder. I was just thinking of buying an oversize carb but then I'd need a new plastic mount to match the new bore or a carb made to mount to the offset holes in the cylinder.

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[Little Al]

It's not so much performance I want so much as a workable amount of power to cut my firewood. And yes I am aware I need to adjust for the muffler mod as well as the port job I'm doing to compensate for the increased air flow. Thanks

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The saw you have is not the best example to try to extract power from ,36cc's is never going to produce a great deal extra my advice would be to clean it all up reassemble with a muff mod set up carb etc.& fit a razor sharp chain if it still disappoints flip & obtain a 50 cc or so saw

 

[pioneerguy600]

The saw you have is not the best example to try to extract power from ,36cc's is never going to produce a great deal extra my advice would be to clean it all up reassemble with a muff mod set up carb etc.& fit a razor sharp chain if it still disappoints flip & obtain a 50 cc or so saw

Best advice thus far.

 

[Old2stroke]

Check my post "Cheap fix for dead cheapie poulans" Mar 27, 2017

 

[Chris-PA]

Yes, you can make those run very well, but you'd be better off getting a 4cc engine to start with. Used engines can be has pretty reasonably on eBay. Still, you can make the 36cc engines run well.

The engines from PoulanPro models have chromed bores and bare pistons, while all the others (Poulan, Craftsman, etc) use bare bore with a chromed piston. You cannot use a chromed piston & cylinder. I've made both run well. The chromed bore is more tolerant of abuse.

Dual ring aftermarket pistons are available, but don't bother. They are only for the bare bore 42cc, and have excessive squish clearance.

Your saw has no anti-vibe suspension - it will make your ands numb in a tank or two. I've switched to the A/V versions.

Also, with that modded muffler outlet in the back, watch out for exhaust that blows around the back to the flywheel side and melts the cover.

Here are some threads I've done on these - this one is just ported:
https://www.arboristsite.com/community/threads/yet-another-42cc-poulan-porting-thread.262612/

Then it got the squish reduced - this saw runs great:
https://www.arboristsite.com/community/threads/reducing-squish-on-a-poulan-clamshell.273087/

This is a bare-bore engine of later design that came out really well:
https://www.arboristsite.com/community/threads/exhaust-delayed-scavenging.292902/

 

[Chris-PA]

Here is a write up on the various version of those saws I did some time ago - might be a few errors/omissions:

Poulan Wild Thing

Models include the 1950, 2050, 2055, 2150, 2175, 2375, PP210, PP262 in displacements from 33cc to 42cc. There is no anti-vibe and they can be identified by the primer bulb and the distinctive vertical duct bulge that runs from the top of the recoil cover into the top cover. They're not that light and fairly wide, but not too bad either.

The engine is a basic clamshell type with a slug piston and open single transfers. The connecting rod is a flat cross section (stamped?), but is fairly thick and I've not heard of this being a weakness. Flywheels have deep fins and they appear to move a lot of air.

Some have chain brakes, some don't. Clutches are outboard type with simple spur drive sprockets. All use 3/8 LoPro chain. Most use Walbro WT carbs and foam air filter that works OK if it's oiled.

Poulan 2250

Models include the 2250, 2550, 2555, PP220, PP230, PP260, in displacements from 36cc to 42cc. These are the same basic design as the Wild Thing family, but have A/V. The A/V uses a spring-type suspension for isolation, which tends to be rather soft and allows a fair amount of movement, but it is smooth. There are considerable differences in the choke and throttle linkages, on/off switch, the carb, the top cover and the air filter mount. The top cover on these has two internal ridges that help keep the air filter seated, which the Wild Thing ones do not have. The choke is located in a terrible position and is really hard to access with gloves.

Chain brakes were optional. All use 3/8 LoPro chain.​

 

[Brian72]

I agree with Al. Not saying don't tinker with it but I'd find a cheap 50cc to build up. Just a better investment for a working saw.

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[Mainemechanic]

Yes, you can make those run very well, but you'd be better off getting a 4cc engine to start with. Used engines can be has pretty reasonably on eBay. Still, you can make the 36cc engines run well

Dual ring aftermarket pistons are available, but don't bother. They are only for the bare bore 42cc, and have excessive squish clearance.

Your saw has no anti-vibe suspension - it will make your ands numb in a tank or two. I've switched to the A/V versions.

Also, with that modded muffler outlet in the back, watch out for exhaust that blows around the back to the flywheel side and melts the case

Through some research and parts manual surfing I have concluded this is the 42cc engine. It has the 41.1 mm bore. There is a few threads about these saws and the marketing tricks the company uses to sell more saws, there's really only two sizes of the clamshells.

What are the advantages of the dual ring piston? And to really pull the power I'd be milling my cylinder Is that what your getting at with the excessive squish clearance?

Yes, there is no anti vibe, yes my hands go a little numb but I've run ****** old equipment all my life it don't bother me to bad. I once had a yard machine push mower that shook so bad it needed at least 1/3 tank of fuel to run cause it would splash in the tank and suck air if there was not enough fuel.

I did not think of the case when I first opened that muffler port, I did after words but it seems to come out and hit the little diverter plate that keeps the hot gasses out of the cylinder heat sink(which I also modded) and shoot up and forward at about a 45 degree angle, it barley warms the flywheel cover at all. Now the 3 ports in the front if I get up close to a tree or log I can feel alot of heat bouncing back at my hand, it's nice now when it's cold but idk how much I'll like it in the summer. I was thinking of buying Another muffler and trying something different and closing the rear ports and run dual tubes out the side or front.

As far as buying a larger and nicer saw, I would love to but they are expensive compared to a few parts and some tinkering on this saw that was free from a good buddy.

Thanks everyone I'll post more pics And updates for my "build" soon, I'm almost done porting it.

 

[Mainemechanic]

And if I go spend the money for a new saw it will probably be bigger than 50cc, id love to have a real rippah. 70cc or so. Seen a dolmar Sachs 70cc saw on CL running and complete for $90. Looked like kind of a neat saw but weighed 21 pounds empty.

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[s sidewall]

21 lbs, good on the back when you get older, be on the shelf collecting dust while you use a lighter saw
60cc saw.


Steve