Project Clearing Saw: Husqvarna 250RX

[Jack_Shaft]

I made a trip to my favorite Stihl dealer today and we had a look in his backroom "saw graveyard" to see if he could find a few of the parts that I was looking for.

In the midst of the junk was a good looking Husqvarna 250RX clearing saw that appears to have low compression. The story I got wasn't that it was straight gassed, but rather that it was used to death with a landscaping company. He tiold me I could have it if I wanted to give it a shot at fixing. Perhaps a jug & piston will solve the issue and I will gain a great clearing saw for the local snowmobile club.

The only problem I have is that I'm not too familiar with Husky's line up, the Husky dealer here really doesn't carry much in parts at all (doesn't even stock one saw!) and after looking around a bit on the internet, I can find very little so far.

With the help of AS.com, I would like to find an IPL, a spec sheet on the saw, some info on this family of clearing saws (i.e. which models use the same casings, etc.) and determine any common problem areas for this particular model.

Any help would be appreciated.

 

[Four Paws]

Husqvarna's website should have the IPL available, as does partstree at this link -> http://www.partstree.com/parts/?lc=husqvarna&mh=10

Jug and piston kit for the clearing saws are pretty pricey.

Here is a 39r that I built for my dad.

 

[Jack_Shaft]

Thanks for the link!

At least now I can tear into this thing.

 

[SawTroll]

Here is an OM, but it doesn't mention the 250 as an RX, just an R.

The engine of the 250 is basically the same as used in the Husky 49, 50Rancher, Partner 500/490/510, Jred 2050 etc.
I think you can use the larger cc versions (51.8 and 53.2) of that engine as well, but I don't know if it involves more than just the jug and piston.

My brother has put chainsaw engines in quite a few dead clearing saws and larger trimmers.

 

[HiOctane]

I would install instead cy/piston from a 252 Rx.Its a bolt on.Muffler was a problem on 250 rx,the stud holes enlarge easily,you have to keep the nuts tight.And if it broke,try to get one in "one piece",it solved the problem.The 250 was prone to seizing i would say,thats why i suggest you the 252 cyl.

 

[Jack_Shaft]

The engine of the 250 is basically the same as used in the Husky 49, 50Rancher, Partner 500/490/510, Jred 2050 etc.
I think you can use the larger cc versions (51.8 and 53.2) of that engine as well, but I don't know if it involves more than just the jug and piston.

My brother has put chainsaw engines in quite a few dead clearing saws and larger trimmers.

Right on Troll, I figured you would have some prior knowledge. It would be fairly easy for me to come up with a top end from a 49 or 50 rancher even from an eBay search. I need to check this thing out good before I make too many moves though, so I guess I shouldn't jump to too many conclusions. A compression test and bevel gear inspection will be the job for tonight.

What is the best way to check out the bevel gears? Is there a way to check for slop and/or binding in the gearhead without a full teardown?

 

[Jack_Shaft]

I would install instead cy/piston from a 252 Rx.Its a bolt on.Muffler was a problem on 250 rx,the stud holes enlarge easily,you have to keep the nuts tight.And if it broke,try to get one in "one piece",it solved the problem.The 250 was prone to seizing i would say,thats why i suggest you the 252 cyl.

That's good advice too no doubt. This one appears to have a good muffler and the engine turns freely, so I guess it wasn't bitten by either of those bugs. I'd love to find a cheapy-cheapy chainsaw top end to slap on it if I could, but if that isn't possible at least now I know which top end to go after.

 

[SawTroll]

I would install instead cy/piston from a 252 Rx.Its a bolt on.Muffler was a problem on 250 rx,the stud holes enlarge easily,you have to keep the nuts tight.And if it broke,try to get one in "one piece",it solved the problem.The 250 was prone to seizing i would say,thats why i suggest you the 252 cyl.

Yes, or from a Husky 51 or Jred 2051, or even from a 55, 2054 (early version), 2055 or P540/P543 etc.

 

[Jack_Shaft]

Yes, or from a Husky 51 or Jred 2051, or even from a 55, 2054 (early version), 2055 or P540/P543 etc.

Wow, I have lots of options then.

55 Husky's are all over eBay, shouldn't be a problem finding a top end if that's the issue!

 

[Jack_Shaft]

OK, tore it down today to take a look and everything seems good minus piston & cylinder, which are really toasted good on the exhaust side.

I suppose the good thing about discovering that's the problem is that it's a pretty easy job. A bit pricey, but easy. I was dreading hauling out the driveshaft and/or bevel gear brgs as I really haven't done that before.

Now I am searching for a replacement top end. Any of these should work, no?:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=230188833230&ssPageName=STRK:MEWA:IT&ih=013

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=110191458991&ssPageName=STRK:MEWA:IT&ih=001

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=230188533567&ssPageName=STRK:MEWA:IT&ih=013

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=280171261494&ssPageName=STRK:MEWA:IT&ih=018

 

[Four Paws]

Do you know WHY it burnt down? Would be a bummer to replace the top end only to have a repeat.

 

[HiOctane]

OK,

I was dreading hauling out the driveshaft and/or bevel gear brgs as I really haven't done that before.

Check if there sideplay on the drive shaft and up/down movement of the shaft,if not ,dont open it.A small sideplay is normal though.Check if the seal seems to leak.The seal at the input shaft leaks sometimes if you put too much grease in the gearbox,you will see grease inside the long tube.And if you have to open it,the best way is to heat up with a propane torch until the bearing came loose.If you have the old style gearbox,you have to remove the 4 bolts "under" the blade first.
As for the 51/55 cyl swap ,ive never done it,but those 51/55 cyl dont have carb bolt holes around the intake to hold the carb as the 250,so it means you need the"intake plastic wall" from those saws.And at this point,im not sure it fits,sure needs mods to the wall to fit in the in the crankcase area.Look at the Ebay cyl intake view,you wont see bolt holes for the carb and the cyl accept rubber intake instead of a flange on your stock 250.So on the cyl swap,i dont know if it fits.

 

[Jack_Shaft]

Do you know WHY it burnt down? Would be a bummer to replace the top end only to have a repeat.

9 chances out of 10, lean seizure. Looks that way on the piston too. Upon further investigation I was told that it came from fleet use so it was used by many hands and likely by somebody who was a tad careless. I also found the cylinder base gasket to be broken in two places.

I will investigate further to see if there are any other causes, but for now I certainly know I need a pis/cyl.

 

[Jack_Shaft]

As for the 51/55 cyl swap ,ive never done it,but those 51/55 cyl dont have carb bolt holes around the intake to hold the carb as the 250,so it means you need the"intake plastic wall" from those saws.And at this point,im not sure it fits,sure needs mods to the wall to fit in the in the crankcase area.Look at the Ebay cyl intake view,you wont see bolt holes for the carb and the cyl accept rubber intake instead of a flange on your stock 250.So on the cyl swap,i dont know if it fits.

Thanks for the note on the shaft inspection, I did some of the checks you spoke about and it seems OK. I will have a good buddy of mine who has worked on these before come by tonight to check the shaft out for me too. Everything seems pretty sano with no excessive play.

As for the cylinder, you have a good point. The csaw cylinders have a round spigot for the carb intake boot whereas the brush cutter bolts up solid with two threaded holes on either side of a machined-flat flange as you say.

SawTroll mentioned that his brother had upgraded some of these with csaw top ends a few posts up from your, I have to question him now...!

 

[Jack_Shaft]

Here is an OM, but it doesn't mention the 250 as an RX, just an R.

The engine of the 250 is basically the same as used in the Husky 49, 50Rancher, Partner 500/490/510, Jred 2050 etc.
I think you can use the larger cc versions (51.8 and 53.2) of that engine as well, but I don't know if it involves more than just the jug and piston.

My brother has put chainsaw engines in quite a few dead clearing saws and larger trimmers.

Troll, I'm looking, shopping and comparing parts right now and I have found a few 51 & 55 top ends on eBay. The intake side of the chainsaw cylinder looks very different from the brush cutter one. The csaw one has a raised intake spigot to accept a rubber carb boot; the brush saw cyl is machined flat with two threaded holes for holding the carb assy tight against it.

Did your brother by chance grab the whole cylinder/ carb assy when he did the swaps you speak of, or did he just do the P & C?

 

[Jack_Shaft]

As for the 51/55 cyl swap ,ive never done it,but those 51/55 cyl dont have carb bolt holes around the intake to hold the carb as the 250,so it means you need the"intake plastic wall" from those saws.And at this point,im not sure it fits,sure needs mods to the wall to fit in the in the crankcase area.Look at the Ebay cyl intake view,you wont see bolt holes for the carb and the cyl accept rubber intake instead of a flange on your stock 250.So on the cyl swap,i dont know if it fits.

I've been looking at that even further now and I see the intake plastic wall or bulkhead that you're referring to:

http://www.partstree.com/parts/?lc=husqvarna&mn=50+(1985-02)&dn=02360015

I suppose if worse came to worse, I could buy a complete parts saw with good mechanical parts and somehow modifiy the bulkhead to fit the clearing saw. Would be a hack job though. I guess if the csaw cylinder doesn't have any threaded holes, the carb must be fastened to this bulkhead. Seems pretty feeble compared to the Stihl setup but it must work well otherwise Husky would never done it this way.

More thoughts to come. I may try honing the cylinder to see if I can save it now. Even if I can rough it out and throw a new piston at it I might be able to make something of it.

 

[Jack_Shaft]

Looks like I'm going to have to pony up and buy the piston assembly, maybe the cylinder too.

Where's a decent spot to order Husqvarna parts from, online?

 

[Jack_Shaft]

OK, tried Partstree.com, they don't ship to Canada.

Any other online retailer of Husky parts that ships to Canuckistan?

 

[HiOctane]

I've been looking at that even further now and I see the intake plastic wall or bulkhead that you're referring to:

http://www.partstree.com/parts/?lc=husqvarna&mn=50+(1985-02)&dn=02360015

I suppose if worse came to worse, I could buy a complete parts saw with good mechanical parts and somehow modifiy the bulkhead to fit the clearing saw. Would be a hack job though. I guess if the csaw cylinder doesn't have any threaded holes, the carb must be fastened to this bulkhead. Seems pretty feeble compared to the Stihl setup but it must work well otherwise Husky would never done it this way.

More thoughts to come. I may try honing the cylinder to see if I can save it now. Even if I can rough it out and throw a new piston at it I might be able to make something of it.

Did you heard about muriatic acid to remove aluminum on your cyl wall.Works great usually,but be careful with this stuff.

 

[Jack_Shaft]

Did you heard about muriatic acid to remove aluminum on your cyl wall.Works great usually,but be careful with this stuff.

Yes, I have heard about it but I'm not too keen on handling the stuff as I already have eczema on my hands.

The cylinder appears to be lightly scored more so than "ribbed" with piston material. I need to have a closer, better look at it to be sure though.