Husqvarna 254XP Rebuild

[Stump Shot]

I think I might shrink wrap it for now.

That actually makes for a pretty good repair.

 

[ZukiRyder440]

@Stump Shot I heard you have ported a 254 in the past. What were your timing target numbers when you ported it? Just curious.

 

[Stump Shot]

@Stump Shot I heard you have ported a 254 in the past. What were your timing target numbers when you ported it? Just curious.

I'll send ya a PM after I go back into the shop and go over my notes.

 

[ZukiRyder440]

I'll send ya a PM after I go back into the shop and go over my notes.

Thank you

 

[XP_Slinger]

That electrical dip coating stuff in a can is pretty handy for such things too. Prolly about a $7 wire there.

I have some of that too, we’ll get her buttoned up.

 

[Stump Shot]

Thank you

Well, after looking over a few 254 build notes, I have to say that I'm getting most of the port timing changes from the machining of the cylinder. Which really won't do you much good. Sorry

 

[XP_Slinger]

Well, after looking over a few 254 build notes, I have to say that I'm getting most of the port timing changes from the machining of the cylinder. Which really won't do you much good. Sorry

Those cylinders are timed very well right out of the box imo. Without a base and chamber cut I can see performance going a little backwards.

 

[ZukiRyder440]

Well, after looking over a few 254 build notes, I have to say that I'm getting most of the port timing changes from the machining of the cylinder. Which really won't do you much good. Sorry

Thats fine.

 

[huskyboy]

I decided to not touch the ports in the mahle 262 cylinder after rattler decked the cylinder to optimize the squish. I saw they were widened to near max width factory. Saw seemed to run good for a small saw. The little bump in compression seems to help the torque of small saws. Looking at your photos I’m surprised how much smaller the lower transfers were in the 254 cylinder stock vs the stock 262 cylinder. What’s the difference in displacement 5 cc or something like that?

 

[PA Dan]

I decided to not touch the ports in the mahle 262 cylinder after rattler decked the cylinder to optimize the squish. I saw they were widened to near max width factory. Saw seemed to run good for a small saw. The little bump in compression seems to help the torque of small saws. Looking at your photos I’m surprised how much smaller the lower transfers were in the 254 cylinder stock vs the stock 262 cylinder. What’s the difference in displacement 5 cc or something like that?

What cylinder was it Mason? I have KS and a Mahle decomp. The last one I built had a Mahle non decomp. I used a thinner gasket to get the squish to .019 and that saw was awesome.

 

[ZukiRyder440]

I decided to not touch the ports in the mahle 262 cylinder after rattler decked the cylinder to optimize the squish. I saw they were widened to near max width factory. Saw seemed to run good for a small saw. The little bump in compression seems to help the torque of small saws. Looking at your photos I’m surprised how much smaller the lower transfers were in the 254 cylinder stock vs the stock 262 cylinder. What’s the difference in displacement 5 cc or something like that?

I honestly thought the 254s were about the same size as the 262. I was very surprised muh self. The 262 has a slightly larger bore and slightly longer connecting rod. I think the displacement difference is right around 5cc.

 

[huskyboy]

What cylinder was it Mason? I have KS and a Mahle decomp. The last one I built had a Mahle non decomp. I used a thinner gasket to get the squish to .019 and that saw was awesome.

It’s got a mahle decomp cylinder. Unfortunately the serial number was worn off on the first few numbers so I can’t see what year it is. Had a 120 carb so I assume later production.

 

[PA Dan]

62cc for the 262

 

[huskyboy]

I honestly thought the 254s were about the same size as the 262. I was very surprised muh self. The 262 has a slightly larger bore and slightly longer connecting rod. I think the displacement difference is right around 5cc.

Do 262 cylinder lowers vary? They were huge on this mahle decomp cylinder. Like almost the size of 660 stihl lowers.

 

[huskyboy]

This is the only photo I have of it after rattler cut the base and cleaned up the squishband that got damaged by bearing failure. You can kind of see the width of the lowers that I circled.

 

[PA Dan]

Do 262 cylinder lowers vary? They were huge on this mahle decomp cylinder. Like almost the size of 660 stihl lowers.

Yes...here is the KS cylinder. It was different from the Mahle non decomp from what I remember.

 

[huskyboy]

Yes...here is the KS cylinder. It was different from the Mahle non decomp from what I remember.

Those uppers look a little tighter than they were on the mahle cylinder I had here.

 

[PA Dan]

Maybe that's what was different? Can't remember and I don't have that saw any longer. I'll look for the pics.

 

[XP_Slinger]

Both models are true in displacement to their respective model numbers. 8cc difference between 254 and 262.

I’ve had my booger hooks in Mahle and KS cylinders and the transfers mirrored what you guys are observing. KS has tighter uppers when compared to Mahle.

 

[PA Dan]

Here they are...