Tips wanted, modding my first saw, a husky 266SE

[Big vin]

I bought a non running 266 for 30 bucks, all it needed to get running again was adjusting the idle and fixing a broken throttle linkage.
Now i would like to mod it just for the fun of it. A bit more than a worksaw, but not a competition saw either. I added some pics of the saw taken apart. Cylinder and piston look just fine, carb is around 18.5mm.

I would like to get some pointers on how much to enlarge the ports, and how to modd the mufler. If there are any good threads to look at please let me know.

Thanx!

 

[Big vin]

Ok, not so much replies as i hoped for

I have searched all of the saw building topics and have made the following plan: I am going to enlarge both intake and exhaustport to 70% of the piston diameter (provided that that is possible, must measure first.) I will leave the base gasket out to bump compression (check first that squish is 0.020 or more) and raise both the intake and exhaust port the thickness of the gasket. I am planning to leave the transfer ports alone, maybe just clean them u a little.

Does that sound about right? Seems like a place to start to me at least.

What about the carb, just leave it and tune H and L?

 

[spindrift7mm]

Welcome ! I wouldn't raise the ports without checking port timing as you may be better off on one or both ports where they are. I know port timing seems confusing but if you set up a degree wheel and just start rotating thru each port event you'll be surprised how it starts to make sense. Do some searches for Port Timing and how to but don't stress on the complicated versions.
T Landrum had a simple version ; int is measured from bottom to top and back down exh is measured from top to bottom and back up blowdown is from opening of exh to opening of transfer. I would set up and run stock timing numbers until you gain confidence. Never change port timing unless you understand why and what. Hope this helps. Ken

 

[Big vin]

I will try to check timing first then, got a lot of figuring out to do!

 

[Big vin]

I have checked squish and it is at 0.030 with the base gasket removed, modded the muffler with some fish gills.
My carbide bits are to small to fit in the ports, so i decided to skip porting for now and get it running properly first.

here is a video of the saw assembled again


Here is a video of my 357XP from 2011 as reference

 

[Big vin]

The 266se takes about 9.5 seconds, the 357 takes about 10 seconds.
The 266 is on a new chain, the 357 on a decent used one, hand filed.

The chain that was on the 266 was cutting terribly, even though i sharpened it. It was cutting crooked en unregular. I checked it and the chisels are not all equal. Some are almost 9mm long, others like 8.13mm long.
Is this difference enough for the chain to cut bad? Allso i am not sure about the depth gages, going to measure them too. Is filing them all back to 8.1mm the best thing to do (man, that is some work using only a hand file)

 

[spindrift7mm]

All cutters should be same. If your comparing cut times try changing your style and simply let the saw cut without all the rocking back and forth. Apply pressure as needed and be smooth, the results will be more accurate. 357 has a nice idle. Ken

 

[weimedog]

I would simply graft a 272 top end on it. Find an OEM 272 used but salvageable, put in either a meteor or OEM piston, build it with Three Bond 1194 for a base gasket and it will handily pull harder than the stock 266.

 

[burl1984]

I built two 266 saws with the bailey's ckn 272 top end kits and dual ported the mufflers. They both have noticeable power gains over the oem 266. to do the modification the 268 intake block gaskets and mounting hardware were required. I think the entire modification with the 268/272 gasket kit was less than 150.00.

 

[president]

the 163a tillotson carb is only 14 to 15 mm stock
Did you widen out the venturi ?

 

[burl1984]

President. Are you replying to my post? Iirc the gasket for the 268/272 was the same exact diameter as the barrel on the oem 266 carburetors. Some widening of the intake on the head itself can be done but I did not attempt it. I suppose widening out the carburetor could be done as well but it seemed such a nice bolt on procedure that I did not bother with any more modifications. With a squish band cut, decking and a woods port I'm thing the 266 would run like a newer oem 372z

 

[burl1984]

Additionally I would make a custom aluminum intake block that could be milled easier and just bolt a larger bore carburetor onto it. I did that with my 101b kart saw with a 38mm mukuni sbn.

 

[president]

sounds like your on top of it, I,d like a 266 myself

 

[motor head]

Additionally I would make a custom aluminum intake block that could be milled easier and just bolt a larger bore carburetor onto it. I did that with my 101b kart saw with a 38mm mukuni sbn.

225 Tillitson will bolt right on.Also 224.A lot more power

 

[Huskybill]

I plugged the governor in the carb. The hand held hole punch using plastic thin paper makes the govenor plug. Then I added a 8 tooth rim to speed up the chain. Set the rakers at .030”. The 266se is a great saw. I missed mine so I purchased another one.