Husqvarna 61 Blacktop - upgrade to 50mm piston

[Marty Lawrence]

Hi all, This is my 1st post here. I have an old Husqvarna 61 blacktop (1986).
I am wondering if it is possible to bolt on a 50mm piston & cylinder kit from a 268xp?
I am not interested in porting. I would prefer none to minimal modifications.
I hope to use existing carb.
I am not interested in the 52mm kits from a 272 - as I understand there is multiple modifications needed.
Do you guys know if what I hope to do is possible?

 

[Gord404]

I think the carb and carb block will have to be upgraded to 268- the rest will be ok and if your thinkig of a cheap china kit- good luck in the long run.

 

[Bob Hedgecutter]

Hi all, This is my 1st post here. I have an old Husqvarna 61 blacktop (1986).
I am wondering if it is possible to bolt on a 50mm piston & cylinder kit from a 268xp?
I am not interested in porting. I would prefer none to minimal modifications.
I hope to use existing carb.
I am not interested in the 52mm kits from a 272 - as I understand there is multiple modifications needed.
Do you guys know if what I hope to do is possible?

First off- what are your reasonings for the upgrade?
Is the 61 still running fine, just not powerful enough- or is the 61 top end burned up?
Secondly, if wanting to use the same carb you will be feeding less air into the system than the genuine 268 set up and not realising full potential of the upgrade.
Thirdly, as noted above- if going for budget grade top end, do not be surprised if there is little to no power upgrade other than psychological and a lesser life span expectation.

If replacing because of a burned up piston and cylinder- address that issue first! Or same will happen to your new top end.

 

[Marty Lawrence]

yes a little more power would be nice.
I did get a cheap 48mm kit from ebay (size matches the original 61). Its running OK for the moment, but power seems less than it should.
I am looking at a Hyway or meteror kit this time 50mm piston & cylinder. I have not been able to find any quality kits with the stock 48mm P&C. So thats the other reason I'm considering the upgrade to 50mm.

 

[Bob Hedgecutter]

Okay, so we are back to - why did you get the cheap top end? Do you know the history or why the original burned up or needed replaced?
If it was unrepaired- it could be part of the low power now- but more likely dubious porting and excessive squish of the knock off version.
Like always- pressure and vacuum test is kind of mandatory with saws of this vintage.

 

[ballisticdoughnut]

Put a 266 top end on it. Will require different intake block, hardware, and gaskets. I ran a 268XP top end on one of my 266’s for a little while and wasn’t impressed. Or you can go 272 top end.

 

[NSEric]

I'd put the 272 kit on it if it was mine, those aftermarket cylinders seam to have better squish and timing. The mods are simple and easy to make it work...
The intake bolts are 4mm just like the 268 will be, but the muffler bolts are 6mm, this might be the same as a black top 61 im not sure but getting new bolts is easy. Then grind a touch on the top cover if the spark plug hits it.
The 61's intake, carb and filter set up works just fine on the bigger 268 and 272 cylinders, there's only a tiny bit of power difference between one with the big 272 carb and one with the 61 carb. The 266 had a small carb and ran right with the newest 272's.

 

[Marty Lawrence]

Okay, so we are back to - why did you get the cheap top end? Do you know the history or why the original burned up or needed replaced?
If it was unrepaired- it could be part of the low power now- but more likely dubious porting and excessive squish of the knock off version.
Like always- pressure and vacuum test is kind of mandatory with saws of this vintage.

I was given the saw, it had little to no compression I didnt know any history of it. It was covered in probably 30 years of filth. The muffler was held on with a hose clamp, the air filter looked like my garden after mulching, pretty much every anti vibe rubber was broken. I was unsure whether it was even worth it. I saw it as a learning experience, so I was going cheap.
After pulling the top end I noticed there was no bearing cage in one of the bearings. And a significant amount of scoring on the piston and cylinder.
I have since replaced bearings & seals, all new gaskets and gave it a good clean up. the saw was actually in pretty good shape under the muck. No cracks, chips etc in any metal or plastic. And even with the cheap P&C more power than my husky55 and is more comfortable and more of a pleasure to use.
So I actually see it now as worth spending a bit more on.
I am one of those guys that learn by doing, but am willing to learn more from you guys on this forum too

 

[RedneckChainsawRepair]

I understand you wanting more from a 61. I just traded my 1986 61 off I redid. Open port and muffler modded. They are just lack luster.

I had my 670 champ and ran them back to back. Wasnt even close to smelling its dust.

 

[Gord404]

nice looking saw- got a 266 in the other day that under all the crud same thing and runs - will leave it and put seals in it etc when I have time- made a 61 into a 266 last week, nice saw- have a lot of oem cyinders etc in my parts but had a doner saw with busted cases- new meteor piston and all the other parts needed done - did lower the squish (25 now) but I have a lathe to do so- bear to start but really moves out- carb setup is also 266.

 

[Marty Lawrence]

I'd put the 272 kit on it if it was mine, those aftermarket cylinders seam to have better squish and timing. The mods are simple and easy to make it work...
The intake bolts are 4mm just like the 268 will be, but the muffler bolts are 6mm, this might be the same as a black top 61 im not sure but getting new bolts is easy. Then grind a touch on the top cover if the spark plug hits it.
The 61's intake, carb and filter set up works just fine on the bigger 268 and 272 cylinders, there's only a tiny bit of power difference between one with the big 272 carb and one with the 61 carb. The 266 had a small carb and ran right with the newest 272's.

You seem to indicate the 50mm piston kit will work with existing carb. I kinda thought it should. Pretty sure when I pulled it appart the muffler bolts were 6mm. I think intake bolts were the same size.
Do you think its better to go new bolts or re-tap the new cylinder to fit the existing bolts?

After doing some hunting I am having trouble finding a supplier in Australia who sells meteor or hyway for the 61 or 268. And with exchange rates & postage It will cost a packet to get from a USA store.

I have come across Tacsum cylinders & piston kits here in Australia. The supplier gives a 12month warranty. They look like (as far as I can tell from photos) decent quality. Have you guys heard of Tacsum?

 

[Bob Hedgecutter]

Yeah na mate- the Carby Doc never sells anything dodgy or cheap.........
Old story- you lay your money down and generally you get what you pay for.
Never used (nor heard of until now) Tacsum- maybe they are the best of the bottom dwellers- who knows. 12 month warranty does not mean a lot if the supposed bigger and better runs no better than an original 61 cylinder eh?
Meteor seem to be low on stock this side of the Tazzie at the mo as well- but if I was in the need of one, I would not be rushing to buy a Tacsum.

 

[singinwoodwackr]

Yes, you can use your 163a carb but you’ll need the 266 intake block and screws. Muffler will work but May require different screws.
However, there are good, used oem 48mm topends out there for less than what you’ll wind up spending on a frankinsaw. You won’t see much of a power difference, if at all, with an aftermarket 50mm top. The 61 is a great saw as is. Fix it with oe parts.

 

[NSEric]

You seem to indicate the 50mm piston kit will work with existing carb. I kinda thought it should. Pretty sure when I pulled it appart the muffler bolts were 6mm. I think intake bolts were the same size.
Do you think its better to go new bolts or re-tap the new cylinder to fit the existing bolts?

After doing some hunting I am having trouble finding a supplier in Australia who sells meteor or hyway for the 61 or 268. And with exchange rates & postage It will cost a packet to get from a USA store.

I have come across Tacsum cylinders & piston kits here in Australia. The supplier gives a 12month warranty. They look like (as far as I can tell from photos) decent quality. Have you guys heard of Tacsum?

The 61's carb will work with all the cylinders. I'd rather have a slightly smaller OEM carb than an aftermarket bigger 272 carb.
The 266 cylinder has a different intake block and bolts than the 268 or 272.
If the 50mm cylinder says it's for a 268, you can reuse the 61's intake, same with the 272 52mm cylinder, it can use the 61's intake and carb.
I had good luck with a cheap 52mm cylinder off amazon, I put it on the older white top 61, it has a ton of compression, good timing numbers and is still running strong. I used the 61's intake, carb and muffler with the bolts for a 272 in the intake and new long 6mm bolts in the muffler.

 

[singinwoodwackr]

The 61's carb will work with all the cylinders. I'd rather have a slightly smaller OEM carb than an aftermarket bigger 272 carb.
The 266 cylinder has a different intake block and bolts than the 268 or 272.
If the 50mm cylinder says it's for a 268, you can reuse the 61's intake, same with the 272 52mm cylinder, it can use the 61's intake and carb.
I had good luck with a cheap 52mm cylinder off amazon, I put it on the older white top 61, it has a ton of compression, good timing numbers and is still running strong. I used the 61's intake, carb and muffler with the bolts for a 272 in the intake and new long 6mm bolts in the muffler.

The intake blocks for the early 61 vs 268 are not the same. The 61 block won't seal well to a 268 block.

 

[Bob Hedgecutter]

The intake blocks for the early 61 vs 268 are not the same. The 61 block won't seal well to a 268 block.

That might be one too many blocks.

 

[singinwoodwackr]

That might be one too many blocks.

There are 3 for this series..and 3 gaskets
I did a pic spread in a thread on that other site.

 

[Bob Hedgecutter]

There are 3 for this series..and 3 gaskets
I did a pic spread in a thread on that other site.

no, your wording- 266 block mounting to 268 block.

 

[singinwoodwackr]

no, your wording- 266 block mounting to 268 block.

Oops...

 

[Gord404]

I have done a couple of these and the 61 block is a different one from the 266 and the 272 takes a different one yet- same one off a 288 and built a 61 into a 266 last week - different carb block- I have tons of parts and parts saws- carb on a 61 has a 4 on the top and 266 has a five- used the 5 off the 266 - think the jets must be bigger- 272 the block and the bolts are long and bolt the whole affair on at once and the long bolts have a plastic coating on them- spacer so everthing lines up-Unless they are different from single coil newer models this is my expierance over the years and your top may or may not fit the 272- amazon sells these or Ftec cheap