Husqvarna 50/51/55 repair thread.

[RIDE-RED 350r]

My first impression of the piston is pretty good. I haven't measured it, just pulled everything out of the box and checked things over. It's a Christmas present for my boy, we will be building this 55 for him. I was in a little bit of a hurry to get pic before he got home from school today.

I do recall folks saying squish is usually quite large on many of the Chinese kits but in alot of cases small chambers offset that. Probably you who I've seen say it. I'll check squish and see what the timing is and I probably won't get too worried about squish unless compression is low. On this particular saw, what is a good range for compression on a stock unit?? Taking a wild guess I would say 140-150?

 

[PogoInTheWoods]

Squish is large in the OEM cylinders, too. AM cylinders just follow suit. Base gasket delete will still leave you with .030 or more in most cases. You should pull 140-150 easy if the kit has decent rings.

A great project for you and your son. (Take lots o' pics!)

 

[RIDE-RED 350r]

Thanks for the info. Yep, I've dealt with some OEM Huskies that came down to mid 30s for squish after BG delete. Some are tighter though.

I sure will take pics and start my own thread so as not to clutter up this one more than I already have (sorry about that Onan). Getting started on my 242 first though. Just ordered my first round of parts for it today!

 

[Onan18]

Thanks for the info. Yep, I've dealt with some OEM Huskies that came down to mid 30s for squish after BG delete. Some are tighter though.

I sure will take pics and start my own thread so as not to clutter up this one more than I already have (sorry about that Onan). Getting started on my 242 first though. Just ordered my first round of parts for it today!

No need to be sorry, that is what this thread is for. Please, post away!

 

[Dub11]

Thanks for the info. Yep, I've dealt with some OEM Huskies that came down to mid 30s for squish after BG delete. Some are tighter though.

I sure will take pics and start my own thread so as not to clutter up this one more than I already have (sorry about that Onan). Getting started on my 242 first though. Just ordered my first round of parts for it today!

Yeah what Joe said ^^^^. Plus all this info will be in one thread and we can see how differet flavor of heads will run.

 

[RIDE-RED 350r]

Well it's going to be a little while as I have that 242 ahead of the 55 for rebuild and I have several other parts for the 55 to chase down. Might try going all AM with this one as Walt suggested a few of us do awhile back to see just how inexpensively we can get a 51/55 back to cutting again. Our 55 is missing several things along with needing a rebuild. But when we get started, I'll certainly post it up in here if that's what you guys would like.

 

[RIDE-RED 350r]

So today a friend handed me a very clean Husky 55 closed port that had burned down to see what it will cost to repair. Found the usual smoked exhaust side of the piston and even a narrow streak on the left side edge of the skirt on the intake side. I believe I should be able to save the cylinder and a Meteor CP piston should do the trick..

But, before I pulled the top end, we pulled the flywheel and clutch and pressure tested it with 10psi checking for audible leaks and spraying soapy water on the usual places. The crank seals didn't leak at all, but the rubber intake coupler that connects the intake partition to the cylinder was leaking like crazy. (seems like a bad design to me, not even a zip tie or something there) Anyway, it seems as though I found the smoking gun but I want to replace that coupler along with the impulse coupler and re-check it just to be sure the crank seals are good to go being the saw is nearly 19 years old.

Any other thoughts or advice from the 51/55 experts??

 

[Onan18]

So today a friend handed me a very clean Husky 55 closed port that had burned down to see what it will cost to repair. Found the usual smoked exhaust side of the piston and even a narrow streak on the left side edge of the skirt on the intake side. I believe I should be able to save the cylinder and a Meteor CP piston should do the trick..

But, before I pulled the top end, we pulled the flywheel and clutch and pressure tested it with 10psi checking for audible leaks and spraying soapy water on the usual places. The crank seals didn't leak at all, but the rubber intake coupler that connects the intake partition to the cylinder was leaking like crazy. (seems like a bad design to me, not even a zip tie or something there) Anyway, it seems as though I found the smoking gun but I want to replace that coupler along with the impulse coupler and re-check it just to be sure the crank seals are good to go being the saw is nearly 19 years old.

Any other thoughts or advice from the 51/55 experts??

Replace the partition, boot, and pulse pipe all at once. The parts are cheap and you don't want to have to do it twice.

 

[PogoInTheWoods]

Smart to leak check a saw before tearing it down. Good man. Many folks don't.

Age and fatigue at that sleeve and the impulse grommet are the typical leak sources that burn up these saws. You're on the money about replacing both the sleeve AND the impulse grommet. Some folks would just flip the grommet around but it's already old and deformed and a known weak point, so why? May seal for a short time or get some Motoseal smeared on it but will fail again. They're cheap insurance at a couple bux for another 20 years of service out of that saw. I've never found a need to replace the partition, but if they're cheap enough you at least get fresh threads for the self tapping fasteners.

As for the piston, the only current source for a 45mm windowed piston for that closed port cylinder is Lil Red Barn. A bit pricey at around $40, but he's the only game in town for those pistons. The other AM sources are 46mm solutions.

I have two closed port 55's with bad pistons and salvageable cylinders but have been reluctant to use Lil Red Barn as a result of reading too many negative comments about doing business there. HLS was supposed to acquire a couple of those pistons for folks who would be more inclined to purchase from them instead. I expressed interest but never heard anything back.

 

[RIDE-RED 350r]

Am I missing something or does that seem like a really weak design with just a slip fit connection on those critical parts?

 

[RIDE-RED 350r]

Smart to leak check a saw before tearing it down. Good man. Many folks don't.

Age and fatigue at that sleeve and the impulse grommet are the typical leak sources that burn up these saws. You're on the money about replacing both the sleeve AND the impulse grommet. Some folks would just flip the grommet around but it's already old and deformed and a known weak point, so why? May seal for a short time or get some Motoseal smeared on it but will fail again. They're cheap insurance at a couple bux for another 20 years of service out of that saw. I've never found a need to replace the partition, but if they're cheap enough you at least get fresh threads for the self tapping fasteners.

As for the piston, the only current source for a 45mm windowed piston for that closed port cylinder is Lil Red Barn. A bit pricey at around $40, but he's the only game in town for those pistons. The other AM sources are 46mm solutions.

I have two closed port 55's with bad pistons and salvageable cylinders but have been reluctant to use Lil Red Barn as a result of reading too many negative comments about doing business there. HLS was supposed to acquire a couple of those pistons for folks who would be more inclined to purchase from them instead. I expressed interest but never heard anything back.

Being that I am fixing this saw for a friend, I don't simply want to blast away throwing every new part it at possible if only certain parts are needed. Were it mine, I would just overhaul the entire thing, top to bottom. Trying to keep the cost down for my friend.

OK, I must be losing my mind... I was just looking on HL Supply and swore they had a Metoer windowed piston on there! Not the case, the Metoer is not windowed... They have a Hy-Way windowed piston. I guess that is the only option if I can save this cylinder. Seems as though I have not heard alot of bad about Hy-Way pistons and cylinders. I hope it works out, as I intend to save this original cylinder and the Hy-Way is the only windowed piston available it seems. http://www.hlsproparts.com/Husqvarna-55-55-Rancher-windowed-piston-kit-p/h31055-w.htm

The Meteor piston is probably best run with Meteor's cylinder due to it's different style of closed ports being like a 357xp. I can't imagine a non-windowed piston would work well with the OEM 55 Closed Port cylinder.

 

[RIDE-RED 350r]

Ok, hold the phone.... So this OEM closed port cylinder is 45mm and not 46mm?? If so, then I guess I'll have to try the Lil Red Barn piston...

Either that or I'm getting confused as all hell! LOL!

Breaking out the caliper tomorrow when I get back after this thing..

I read your post three times before the 45mm thing hit me Pogo! My mind is going a hundred different direction with saws right now.. Brother Josh is getting ready to start a 281 build, I'm ordering parts and getting ready to do my 242, I have a 55 open port of my own that is apart and waiting for it't turn on the bench, and now this 55 Closed Port.. System overload!

 

[PogoInTheWoods]

The closed port top end is 45mm / 51cc. As mentioned, all the other windowed pistons available except from LRB are 46mm.

And you'll be surprised at how well everything tightens up with new rubber. Also realize it's actually a pressure fit when the whole assembly is together by virtue of the air filter base being fastened to the case and exerting a certain degree of force toward the cylinder. The design can be debated and most consider it pretty lousy..., when the rubber fails. Works pretty good until then and will again after new rubber is in place.

I will add that a 'pressure only' leak test is only half of a leak test..., especially when it comes to the seals. Pressure can often mask a vac leak at an oil seal and also at a decomp button (if the saw has one).

 

[RIDE-RED 350r]

Copy that Sir... See my post above that I've edited three times! LOL!

Anyway, stupid as it sounds I haven't gotten myself a vac tester yet. I REALLY need to! Maybe in light of that, I should just go ahead and replace the crank seals for good measure as after all, they are pushing 20 years old now. I fully understand that pressure may not present evidence of a bad seal that only leaks with vacuum. I'm getting into too many saws to keep putting off getting a vacuum pump. Batting 1000 so far replacing crank seals though.

 

[RIDE-RED 350r]

FWIW, I picked up one of those Performance Saw Supply windowed pistons from Lil Red Barn for my 242 build. I bought through Ebay and everything went silky smooth as far as getting what I ordered and timely shipping. It measures almost identical to my OEM piston, which according to Tor, (AKA: Mr.242) is a real issue with AM pistons for the 242. See my 242 thread for the detailed comparative measurements if you are interested... I don't want to muck up this thread with things not related to the 55.

I'm probably going to end up getting that windowed piston for this 55 as well, so say hello to your guinea pig.

 

[PogoInTheWoods]

I've actually read good reports about the piston itself. Just that it can be a hassle over there if an order doesn't go quite right.

While we're on the closed port subject, here are a couple of ways to tell a closed port 55 from an open port for those who haven't run across this stuff elsewhere. The easiest way (depending on vintage and if the saw hasn't been 'dicked with') is to just check the label on the top cover if it has one. Some do. Some don't. The first label is a closed port saw -- 51cc. Second is an open port -- 53cc.

The cylinders are also markedly different. First is an open port, second is closed. Notice the fin difference at the air tube. Way more clearance/shorter fins with the open port.





Top view is also a good determining factor with the open port having the slightly smaller footprint and rounded shape at the front right. The closed port fins are also angled. The plug location is also open between the top two fins at the front and has that little deck at the rear. And in this case, the open port cylinder has 46 stamped on it which makes it obvious, though that's not typically there in my experience.


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[PogoInTheWoods]

Lastly, the difference in exterior shape of the ports is also fairly obvious with the closed port being a bit more bulged and having a shaved spot on the flywheel side for flywheel clearance. (Open on the left, closed on the right.)

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There's been discussion about identifying open or closed port by the "Air Injection" location on the recoil cover sticker and also speculation about serial numbers and manufacturing date providing a clue, but I personally don't put much faith in either. All I can say from experience is that there are more closed port 55's out there than folks realize..., mostly burned up unfortunately. Out of the six or eight 55's I've run across, three were closed port. Pretty high percentage.

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[RIDE-RED 350r]

Well, this 55 Closed Port cylinder has been saved although two mild vertical scratches in the plating near the exhaust port remain. My 359 had a scratch very similar and it runs fine pulling about 165psi with the base gasket deleted if I recall.. Using a Q-tip I rub a little muriatic acid on the transfer(being careful not to let acid run into the port and eating the cylinder casting) and let it work for a few minutes. Then wipe the acid out with a water soaked shop towels, dry, then sand by hand. Repeat as necessary.

Got the pieces to make myself an oil pump drive gear puller for about $3. I'll post up as to whether it works when I finish it and give it a try.

Working on removing transfer from XP_Slinger's 281 cyl now.

 

[RIDE-RED 350r]

Well boys, my puller worked like a champ. It's just a 1/2" pipe coupler, a 1/2" by 2" piece of pipe, a 3/8" nut, washer, and bolt that's 4" long. Weld the washer and nut to one end of the pipe and away she goes. Not bad for about 3 bucks.

 

[PogoInTheWoods]

Nice job!