So do I have a problem... or should I just start hanging out on the Poulan thread?

Last week I found myself harvesting the spring mounts out of a tree crushed Husky 450 to make a new top mount for my S25CVA, the little rubber ones are always busted. Now with the mount fixed I put it back into action last weekend where I got a new found appreciation for these little buggers when limbing and preparing the area to drop a broken walnut tree in the 90+ heat while it was raining all day. I was watching caddguy using it to drop a 12" tree and buck it up instead of his 394 or my ported 371 when it dawned on me that I can update these things and really make a nice saw out of them. I'll post some pictures of the AV mount mods after I finish the other two.

Yesterday I bought 2 Poulans off CL. A S25VCA and a 4300CV. Really I wanted another S25CVA to go along with the two 25's I already have (one is getting weak ). It's already torn down and will take a trip through the jet spray along with the two 394's this weekend (maybe the 394's will redeem me).

To make matters worse I bought a S25DA from an AS memeber and then today I buy another S25CVA off eBay. :help:

POULAN SUPER XXV 16" CHAINSAW CHAIN SAW RUNS - eBay (item 190558026183 end time Jul-29-11 07:53:51 PDT)

The plan is to port these little bastards and give them updates like chain brakes and maybe someway to adjust the carb without taking the cover off... :angry2:

Check out the chain brakes... anyone ever had a S25 with a chain brake?
POULAN S25DA / S25CVA WITH 3/8 PITCH CHAIN BRAKE KIT - eBay (item 360381109713 end time Aug-18-11 17:30:36 PDT)

Anyone know where I can get some Poulan green paint? I pretty sure I have a problem.

srcarr52 said:

Last week I found myself harvesting the spring mounts out of a tree crushed Husky 450 to make a new top mount for my S25CVA, the little rubber ones are always busted. Now with the mount fixed I put it back into action last weekend where I got a new found appreciation for these little buggers when limbing and preparing the area to drop a broken walnut tree in the 90+ heat while it was raining all day. I was watching caddguy using it to drop a 12" tree and buck it up instead of his 394 or my ported 371 when it dawned on me that I can update these things and really make a nice saw out of them. I'll post some pictures of the AV mount mods after I finish the other two.

Yesterday I bought 2 Poulans off CL. A S25VCA and a 4300CV. Really I wanted another S25CVA to go along with the two 25's I already have (one is getting weak ). It's already torn down and will take a trip through the jet spray along with the two 394's this weekend (maybe the 394's will redeem me).

To make matters worse I bought a S25DA from an AS memeber and then today I buy another S25CVA off eBay. :help:

POULAN SUPER XXV 16" CHAINSAW CHAIN SAW RUNS - eBay (item 190558026183 end time Jul-29-11 07:53:51 PDT)

The plan is to port these little bastards and give them updates like chain brakes and maybe someway to adjust the carb without taking the cover off... :angry2:

Check out the chain brakes... anyone ever had a S25 with a chain brake?
POULAN S25DA / S25CVA WITH 3/8 PITCH CHAIN BRAKE KIT - eBay (item 360381109713 end time Aug-18-11 17:30:36 PDT)

Anyone know where I can get some Poulan green paint? I pretty sure I have a problem.

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Yup... you got a problem... But when you figure out a way to make those saws actually perform and start like they should, let me know... I'll mail you mine... On the other hand, they last forever!!!

Hedgerow said:

Yup... you got a problem... But when you figure out a way to make those saws actually perform and start like they should, let me know... I'll mail you mine... On the other hand, they last forever!!!

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They can have troubles pulling fuel up to the carb, most of the time it's the reed valve that isn't seating correctly and it killing the crankcase signal to the pump on the carb. Tip them forward to aid the fuel getting to the carb and they'll start much quicker when they've been sitting for a while. If you have problems with hot starts then it's probably carb tuning. I've found that most of them don't like idling low enough to keep the chain from moving.

Have you ever replaced the reed with something made of a different material? This thought has crossed my mind a time or two, but figured someone would have done it if the idea was worth a damn...

Hedgerow said:

Have you ever replaced the reed with something made of a different material? This thought has crossed my mind a time or two, but figured someone would have done it if the idea was worth a damn...

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I've thought about it. I know Mototusani (V Force Reeds) sells generic reed material. I'm sure if I called them they'd be able to get me something with the correct stiffness but with carbon fiber like that I would probably have to fashion a read cage to keep them from opening too far and breaking apart.

They could benefit from a slightly stiffer reed and maybe a cage. Run them with the cover off and you'll see a lot of spit back through the carb. This is one reason why you have to set the carb lean while you have the cover off because the spit back will cause a richer mixture when the carb box cover is back on. <-Why I want to figure out how to make it externally adjustable.

Hmmm, now I'm thinking of a completely different filter setup? Wow I could really geek out on this. :bang:

Yes you could... I like my little top handles, but they sure could use some upgrades... If you come up with something earth shattering, post it up... Maybe my old timers won't have to sit in the saw tree so much...:hmm3grin2orange:

As a matter of fact, I have a 61cc saw that's a reed motor as well. The carb set up is better than the little top handles, but I can't help but think there's so much more power there to be had than what it shows. :msp_confused:

Pipe It

Hedgerow said:

As a matter of fact, I have a 61cc saw that's a reed motor as well. The carb set up is better than the little top handles, but I can't help but think there's so much more power there to be had than what it shows. :msp_confused:

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Reed motors like pipes because they can pull extra air/fuel through the reed when it's in the RPM range for the pipe. They can't do it on a piston ported engine because the intake port is closed by the piston.

ok this is thread is old....... but you can pipe a reed saw??? I thought the reed restricted rpm's and performance ??????

For sure you can. Most snowmobile engines are crankcase reed induction with pipes. Reeds like pipes.

Some misconceptions about reeds exist;

-Reeds are 'older tech' than piston-port engines. The opposite is true. Look at the OLD 2-stroke stationary and drag saw engines. They're all piston-port. On motorcycles, piston-port and rotary/disc valve engines were the most common until the late 1960's/early 1970's when reed valve layouts became more common. Current high performance 2-stroke motorcycle and kart engines are almost all reed valve (with the rest being rotary/disc valve). The hyper RPM model airplane and car engines (30K RPM plus with some) are all rotary valve.

-Reed engine 'spit back' is caused by a 'leaking' reed that doesn't sit tightly closed at rest. Not true. 'Spit back' is the reversion that happens during the time period before the reeds slap closed after having swung open. Reeds don't open/close instantly (no matter how 'tight' they are at rest). Their opening/closing can be graphed with crank rotation (as can the intake port on a piston-port or disc valve engine). Reed engines that 'spit back' more usually have very short intake tracts (because they're most often in a horizontal cylinder layout that lends itself to a short intake track). The resulting shorter intake charge has less inertia to resist reversion (and therefore have minimal 'spitback').

-Reed engines 'spit back' while piston port engines don't. Nope. Piston-port engines with similar length intake tracks 'spit back' as much as reed valve engines. Saw designers have countered that with relatively long intake tracts (measure from the piston to the carb on your saw) to create long intake charge columns with substantial inertia. Reed valve engines with long intake tracts (Poulan 4200-8500 series, Homelite C/XP series, etc) don't 'spit back' much at all.

Horizontal cylinder piston-port saws (McCulloch 10-series, Stihl 040/041 series, etc) have substantial 'spitback' because of their short intake tracts. Most 10-series Macs have a 'spitback shield/collector' above the carb throat. The first 10-series saws (with a domed filter) have a flat rubber 'spitback shield' section of the air filter itself, directly over the carb throat for the same purpose.



The hard starting (and poor empty/drained fuel pumping) experienced with the Poulan XXV and Micro series saws isn't due to a reed that's sitting slightly open at rest. Because of their fuel tank position in relation to the carburetor and their long fuel lines, these engines do require healthy carb pump section diaphragms and crank seals. If the seals are leaking (and they often are by now as the newest of these saws were built 17+ years ago............with most MUCH older), then impulse signal will be weak.

I've never had a saw in those two series have poor impulse signal due to a reed that didn't sit tightly shut at rest. Not talking about a reed prevented from EVER closing by a bit of debris......that's different. I have cured many 'hard starting' and 'hard to tune' Poulan tophandles by rebuilding the carb and replacing the crank seals.

Crank seals for the Micro series are still available from Poulan and Husky outlets. 530019059 is a current Poulan AND Husqvarna #. My dealer even stocks them still. Cost for them is between $3.00-$4.00 each. SKF 4913 is the 'industry' number for those seals. I have yet to find anyone who sells them as cheap as what I can get the Husky/Poulan seals for however...

Crank seals for the XXV series were still available until very recently. Poulan/Husky JUST discontinued them sometime in June 2014. 530019051 is the part # for them. SKF/CR 5510 is the 'industry' number for those seals.

Shaun is a nerd!

nstueve said:

Shaun is a nerd!

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Isn't that the pot calling the kettle black.

nstueve said:

Shaun is a nerd!

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Yeah..............but he's a badass nerd.

And the post by Aaron... brilliant!!! He's a NERD too!

watsonr said:

And the post by Aaron... brilliant!!! He's a NERD too!

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You couldn't toss a mini-mac around here without hitting a nerd.

Shaun I'm really liking that J-Red full-wrap that you modified for use on the Husky 268/272's. Bolted right up and handles well. Thanks again for hooking me up with it.

Eccentric said:

Shaun I'm really liking that J-Red full-wrap that you modified for use on the Husky 268/272's. Bolted right up and handles well. Thanks again for hooking me up with it.

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No problem, I liked it too but it didn't work well with the chain brake. So I converted a 372 full wrap onto the my 272... now that was like a Cadillac. I wish I hadn't of sold that one.

I put a 281/288XP CB lever on my 272XP clutch cover. Clears that full-wrap fine. The original half-wrap application lever did hit the handlebar before CB reset however.

Husky had a full-wrap application CB lever for the 268/272. Different part # than the 288 lever. Seen them on 'Western' 272XP's. Also have seen a couple NOS full-wrap levers on feebay over the last few years. The 288 lever works fine though.

Husky also had a different clutch cover (and a corresponding complete cover/CB assembly) for the full-wraps too. It's notched on the bottom to more easily clear the bar studs when removing/installing the cover with the full-wrap handlebar on the saw. I haven't had a problem with my 'regular' cover with the full-wrap though.

Eccentric said:

I put a 281/288XP CB lever on my 272XP clutch cover. Clears that full-wrap fine. The original half-wrap application lever did hit the handlebar before CB reset however.

Husky had a full-wrap application CB lever for the 268/272. Different part # than the 288 lever. Seen them on 'Western' 272XP's. Also have seen a couple NOS full-wrap levers on feebay over the last few years. The 288 lever works fine though.

Husky also had a different clutch cover (and a corresponding complete cover/CB assembly) for the full-wraps too. It's notched on the bottom to more easily clear the bar studs when removing/installing the cover with the full-wrap handlebar on the saw. I haven't had a problem with my 'regular' cover with the full-wrap though.

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And that is the beauty of having a plethora of extra parts around. Just mix and match until you have something you like.

I'm in need of some 670 parts if you have any?