61 carb question

Did any husky 61's come with the 20mm hs260 carbs. I am converting to 278, but when I took it down, it had a 260 carb.

come on fellas, someone should know this

Just a puzzle, anyone want to help?

Larry

Not sure what your are converting to, a 278? Never heard of that. 260 carbs did not come on stock Husqvarna 61 saws. You might check if you have a 268 or 272 piston/cylinder on your Husqvarna 61 crankcase. :msp_thumbup:

I think the later 61 with the single coil went to the 260 carb. That would be the carb needed to do a 268/272 upgrade.

I believe you will have to drill a hole in the top cover for the idle adjustment screw, the smaller carb had the screw in the crankcase and the larger carb has the screw in the carb. Other than that I believe it is a bolt on deal. I believe the earlier 61 had the 163A and the later had the 254A but the 268/272 both had the 260.

thanks for replies on 61/278 carb.

The 61 that I was converting to 278 came with a tillison hs260 with a 20mm bore. The bore is 48 mm so I think that is the 61 standard bore. The cover was right for the carb adjustment, but the standard 278 filter assembly will not fit under the cover. The profile of the cover is too high.

The 61 cylinder looks like it had some mild polishing done to it. It has open transfers. I thought it looked bigger than the 278 cylinder I have but I put a piece of paper in the 278 cylinder and marked it off and the 61 is smaller. I am going to gasket match the 278 ports and I am going to check the time on the ports. I am also going to check the squish and adjust that if necessary (I have a mill and lathe) to get it to .020 from what I have been reading. At that point I am going to put it together and see how it runs.

I have been reading some posts on how timing is done and I will find out what the timing is and see if can get some advice on whether it needs to be changed.

Thanks for the feedback.


Larry

lps8 said:

The 61 that I was converting to 278 came with a tillison hs260 with a 20mm bore. The bore is 48 mm so I think that is the 61 standard bore. The cover was right for the carb adjustment, but the standard 278 filter assembly will not fit under the cover. The profile of the cover is too high.

The 61 cylinder looks like it had some mild polishing done to it. It has open transfers. I thought it looked bigger than the 278 cylinder I have but I put a piece of paper in the 278 cylinder and marked it off and the 61 is smaller. I am going to gasket match the 278 ports and I am going to check the time on the ports. I am also going to check the squish and adjust that if necessary (I have a mill and lathe) to get it to .020 from what I have been reading. At that point I am going to put it together and see how it runs.

I have been reading some posts on how timing is done and I will find out what the timing is and see if can get some advice on whether it needs to be changed.

Thanks for the feedback.


Larry

Click to expand...

You keep referring to a 278. Never heard of it. Are you thinking 268 or 272?

I converter an early 61 to a 268XP couple of years ago. Biggest problem was the intake and carb attaching bolts. Something also thru a curve at me with the carb, to a point where I couldn't easily upgrade it to the larger Tillotson, but I can't remember exactly why? Might have been the access to the idle speed screw as mentioned above.

Had to use the 61 air cleaner and make room for the spark plug in the 61 top cover. For some reason couldn't bolt down a 268XP or 272XP top cover. All in all, too much effort, and woln't do that conversion again. Better off buying a 268XP or 272XP right to start with, and completely/correctly rebuilding it....IMHO.....Cliff

Cliff R said:

I converter an early 61 to a 268XP couple of years ago. Biggest problem was the intake and carb attaching bolts. Something also thru a curve at me with the carb, to a point where I couldn't easily upgrade it to the larger Tillotson, but I can't remember exactly why? Might have been the access to the idle speed screw as mentioned above.

Had to use the 61 air cleaner and make room for the spark plug in the 61 top cover. For some reason couldn't bolt down a 268XP or 272XP top cover. All in all, too much effort, and woln't do that conversion again. Better off buying a 268XP or 272XP right to start with, and completely/correctly rebuilding it....IMHO.....Cliff

Click to expand...

Agree withh Cliff! I did a 61 conversion to 268 on SIL's 61 white top last year. White top is cool looking tho with the plug boot sticking out of the top like the 65-77.
Shep

your right 272 super

Old age is setting. This is proof. It is a 272. I don't know where 278 came from. I have a 272 I just bought. Have not checked it out yet. Was not a runner, but supposed to have compression and spark. I do not see a problem with the 61 that I am converting. The only thing that I see won't work is the 272 filter top. I hope to get to look at it this weekend. Don't have a lot of time, but sure want to smell some smoke. I'm a piddler, like to make stuff, have most every kind of tool, including mill and lathe, and lots of wood working tools.

I am building our "retirement" home. It is custom and I have been doing most of the work. Log cabin siding, all wood inside, cedar cabinets and vanities (I'm building using cedar milled on my saw mill, planed, and dried). And help has been hard to find. With the unemployment rate what it is, I don't understand getting only 2 or 3 good applications in a month for a carpenter or helper. Strange.

Thanks for the feed back everyone.

Larry