61 to 272-clearance questions

[burnses]

I cant think of a stihl model line that you can do the same amount of cross pollination between brand (husky/jonney) and within the same brand. Fun and fairly economical too a big part of what attracted me to this particular series....

sap can

 

[Dieseldash]

Howdy guys,

I started a hot rod conversion on my old 61 this week too. Glad I "saw" this thread. This saw has cut a crap ton of wood in its life and it's been abused with little maintenance. It was getting weak on compression and I couldn't see just dumping this old girl. The 61 is a solid saw that just trucks along. Not a screamer by any means but just a loyal old dog that grunts thru a days work. I love this chassis saw (own a Jonsered 670WC also) so I figured I'd fix it up. We cut a bunch of beatle kill wood all above 9,000 ft so some more power would be a plus.

Ordered up a Hutzl/Farmertec 272xp top end and bigger carb with intake. The cylinder I recieved looks like a nice casting with smooth ports and it's even made in Italy. I took the air hose and sprayed out at least a pound of saw dust gunk from inside the saw and took it apart. The cylinder looked surprisingly clean inside and would likely last another decade with just a new piston and rings ( I use Amsoil Interceptor in all my 2 strokes from weed whackers to sleds) Test fitting the Farmertec jug the cylinder base flange was too tight to insert into the case. Not sure if it was out of spec or my cases were the issue but I had to file material from the new cylinder to get it to fit. Planning on a no base gasket build to bump compression with a muffler mod. I would of had it back together but I didn't have the correct carb bolts for the 272. Should be here next week and I'll post more once the build is complete. Also a few pics of the build, the gray top cover test fit fine but I didn't have a plug in it. I'm out on the road so more to follow.

A big thanks to Walt, Bob and the rest of you guys on here that have created a wonderful online resource.

 

[Cantdog]

I certainly trust you buddy, but we have a puzzler to solve here. I have some 670's that share the 272 plug angle. They are single coil saws from 92 and 97. I have an additional cylinder that I installed on a 1987 625. It also has the taller plug. As does a 1992 625II. My guess as to what's going on here: There are early and late 625 and 670 cylinders. (630 remained the same throughout it's run). What I remember is that they went to a longer "neck" on the intake port when they switched from the wire boot clamp to the band style clamp. (And the intake boots were also changed). Could they have changed the plug angle at the same time? I really don't know and I don't have any of the early wire clamp cylinders to look at. So, you're going to have to clear this up my friend.

On to the top covers themselves, The cylinder cover really doesn't matter here. The later air filter covers all have a bigger spark plug hood, including the 630 even though it's plug angle never changed. The new filter cover will fit the early cylinder cover. Of course none of them are available so we have to make do with what we have. My 625/70 has the old filter cover and while there is that unsightly 1/4" gap because of the poor fit, it more or less works. The advantage with the 2 piece Jonsered set up is that the cylinder cover can still be secured properly.

Still the most fun chassis project wise for me. Another home grown model I built is a "636 Super". Used a 50mm 266XP cylinder on a 1985 630. 266 has the same plug angle as the 630, and requires zero changes to the intake. Same intake block, gaskets. Gonna run that one tomorrow.

Ah-Ha.....The early and late cyl changes make sense to me. Now, if using a late cyl cover with a late air filter cover you have no or little gap under the plug hood but using an early cyl cover and a late air filter cover gives you the 1/4" gap...yes? So the late cyl covers are taller than the early ones...correct?? I have not done much with the 625 or 670's yet though I have been acquiring bits and pieces and complete saws. It is almost never ending the combinations folks have tried. Jerry (pioneerguy600) brought me down a 670 that he had built out of boxes of parts.....an older two coil unit. I took the covers off it and found it had a solid isolation block like a 630...after much puzzling....I discovered it had a 266 cyl and a 630 carb....I have an extra 670 P&C, boot and carb so it will be going back to OEM..ish. I go have a complete Champ that looks nice but will require a thorough going through. That may become my "672".....with some additional grinding as well...LOL!! I do truly enjoy this family!!

 

[spike60]

Nice job there DD. That saw has a lot more cutting ahead of it. I used the smaller venturi 61 carb on mine cause it was there. Did my usual simple mods to the saw though. Muffler, gasket delete and a little off the intake side of the piston skirt.

OEM or aftermarket, the only interesting cylinders for this entire family of saws still available is the 272 kit, so we have to find a way to make them work on the various models. Open port 61 and 268 kits are also still available, but obviously we'll all go for the 272. It also helps that all of the 272 intake stuff is also available.

Gotta say I'm curious about that "made in Italy" cylinder coming in a farmer tec box from Huztl. Especially with you having to remove a little material to get it to work. It does have the "twin T's" that Tecomec uses. Can you share what you paid for it?

 

[Dieseldash]

I ordered that cylinder off Hutzls eBay store $34.88 with all the gaskets seals and bearings. They called it nikasil coated. I've got another pic showing more of the casting quality and ports. Much nicer than I was expecting after all the horror stories I've heard of some of their parts. I'm gonna run it as is without touching the ports. For now I'm not splitting the cases to install bearings or doing seals. If it ain't broke don't fix it.

Hey Spike do you have any info on your piston skirt mod?

 

[svk]

Good point that DD made was that the intake bolts for the 272 are larger diameter than the 61. We learned that during assembly as well.

 

[weimedog]

Wonder if that "Made In Italy" was done for another supplier? Was it done to "fake" a supplier?? I guess what's more important is does it RUN! Video's please. Plenty of out sourcing, cross sourcing, and just plan misleading going on in the AM marketplace. That's actually a nice looking part from the pictures. I remember when BMW bought the Italian Husqvarna motorcycle line and then proceeded to have motors build in China and then assembled in Italy.......then KTM bought the brand and a Chinese company bought the rights to several of the old Italian Husqvarna models sold under the SWM brand...what was an Italian brand of dirt bikes & still listed as an Italian company.

 

[president]

Wonder if that "Made In Italy" was done for another supplier? Was it done to "fake" a supplier?? I guess what's more important is does it RUN! Video's please. Plenty of out sourcing, cross sourcing, and just plan misleading going on in the AM marketplace. That's actually a nice looking part from the pictures. I remember when BMW bought the Italian Husqvarna motorcycle line and then proceeded to have motors build in China and then assembled in Italy.......then KTM bought the brand and a Chinese company bought the rights to several of the old Italian Husqvarna models sold under the SWM brand...what was an Italian brand of dirt bikes & still listed as an Italian company.

In the pic of the new cyl,it appears to show the 2 ts inverted from one another does it not?

 

[spike60]

The 2 inverted T's are the Tecomec symbol. Identical to what I have on some Tecomec 242XP cylinders. (In an actual Tecomec box).

One guess, and we an only guess, right?--Could be a legit Tecomec cylinder that was out of spec like DD mentioned about getting it to seat in the crankcase. What they might call a "second". Sold to Huztl/Farmer tec who packaged it in their own box. This is not a bad thing at all, cause Tecomec makes very good quality stuff and once corrected that jug ought to be better than most castings from China by a good margin. Looks like a Farmer Tec piston and circlips. If that theory is right, that's a good deal for $35.

And like Walt says, it's all about how she runs. He's also right about all of the cross sourcing and musical boxes that has become the norm with these AM parts. In this case though it looks like you ended up with a better quality part. Keep us posted when you fire it up!

The piston skirt trick is to take .030 off the intake side of the skirt to get a little increase in intake duration. That plus deleting the gasket gives a total of about .050. Probably a little more worthwhile on this project with me using the smaller venturi 61 carb.

 

[weimedog]

Or is tecomec out sourcing..

 

[Sty57]

I have a question about top covers for 266 project.

Is there any other covers that will fit a 2pcs coil 266?
61, 268, 272?

I'm looking for a cover and it would be easier to find one if multiple covers would fit.
Thanks

 

[rynosawr]

Well, I have been super slow to install my new Husky OEM 272xp piston and cylinder (that I got from Spike 60) on my Jonsereds 630, and now with this plug angle issue, I am not sure what to do..


Do I need the later model tall covers from a 670?


Or, is there enough meat on the cylinder to mill it and drill it and install a steel threadsert for the lower spark plug angle for a 630?

 

[Haywire]

Got a grey top cover for sale if anyone needs one..

 

[old 040]

I was able to use the gray tops with no clearance issues on both of my old early 61 swaps, one has a closed port 268 cylinder with a 266 pop-up piston and is a very strong runner, the other has a cheapy AM 272 cylinder kit that I ground on a little, I did use Caber rings on the piston though, it also runs very strong, great old saws to run.....

 

[Sty57]

I tried this yesterday on my 266.
I used one of these grommets. I did have to open the hole in the tank just a bit.

Then I would've been able to use a standard curly line but of course I didn't have any at the time at home.

 

[Sty57]

The key was sheared on mine when I got it. Stopped by the dealer to get one. He wanted $1.80 for one piece. And he had to order it.
I ordered these from McMaster-Carr, 25pcs for $7.17.

There 3mm x 3.7mm x 10mm, seems to fit good in my eyes.

 

[svk]

Got a grey top cover for sale if anyone needs one..

Does anyone have an orange 266 and a grey top 61 to compare profiles?

 

[spike60]

Well, I have been super slow to install my new Husky OEM 272xp piston and cylinder (that I got from Spike 60) on my Jonsereds 630, and now with this plug angle issue, I am not sure what to do..


Do I need the later model tall covers from a 670?

If your 630 is a newer single coil "II" model, the filter cover should have the larger spark plug hood. Like I said above, It's the filter cover, not the cylinder cover that is important. And we are maybe overstating the problem here somewhat when using Jonsered top covers. I have a saw with the "doesn't fit" early filter cover. I'll get a pic up tomorrow, along with pics comparing the early and late filter covers. There is about a 1/4" gap, but it's not like you can't do it.

Husky's are another matter because they are use a one piece cover and the spark plug interference prevents you from bolting the cover on. The Jonsered cylinder cover can be bolted down just fine as it's only the filter cover that hits the spark plug.

@svk---Steve, the orange 266 and gray top covers are the same mold. The white 61 covers and orange 162SE covers are a different mold with even less clearance.

@Sty57--Early twin coil saws and the later single coil saws have slightly different crankcases and the top covers wil not interchange between them due to the location of the bolt holes being different.

 

[svk]

Thanks Bob!

Hoping to have my "custom" spacer back this week.

 

[Sty57]

Thank you Sir @spike60.
That should help me narrow down my search a bit.