husqvarna 55 closed port

[chuck shelly]

hi guys, was there ever any data on the husky 55 cp like hp max rpm what carb used? I went out and broke in my two saws today. a 50 special with the oem cyl and a hyway 45mm piston and ring. new bar and chain .325 stuff. ran very well considering the refurbed 1989 cyl and Chinese piston and ring. then I ran my 51 with a new oem 46mm cly and piston. it ran quite a bit better with a new .325 chain. I am wondering how much more power is a cp than a open port 46 mm. I,ve seen 3.3 hp @ 12,500 rpm for the 55 open port. is it really worth it to build a 46mm closed port? thanks, chuck

 

[cus_deluxe]

im not sure on exact hp specs, but the closed port 55 cylinders(jonsered 590 is same) are pretty legit. very similar to p5000/jonsered 490 cylinders, which are still very competitive with more recent 50cc saws, just 1 mm bigger. not sure of the chamber size on the cp55 cylinder, but the 5000/490 cylinder has a TINY chamber from the factory, so very little work needed to get to a good spot with ports and compression.

 

[Cliff R]

I've owned quite a few 55's and a two 51's. I sent all of them down the road but my two Closed Port 55's. The open port versions are still excellent saws, and actually have a broad/smooth power curve and work best with 18" bars in .325". The CP versions in contrast have a narrower power curve and prefer high RPM's in the cut and are noticeably stronger at high RPM's than the open port versions. So the trade off basically is lacking the mid-range power and narrower power range.

They outfitted the later "Rancher" 55's with 3/8" and main came with 20" bars. That's a little too much for them, IMHO, but they would still be OK for firewood cutting if you didn't "push" them really hard.

The biggest problem with the CP versions is finding OEM P/C''s for them, NLA far as I know. Most of the ones you find for sale with have P/C issues from either being straight gassed, developed an intake leak, or just never correctly adjusted and ran too lean. One of my CP 55's came from Ebay and smoked P/C. It took a little work but it cleaned up well enough and been working fine for over 15 years now. The other one has a mint P/C. Both see a lot of use here, and have never grumbled once or given me any issues anyplace. Power is excellent for the CC's. CP 55's are basically a "pro" saw that oils the chain all the time instead of when it's turning........Cliff

 

[Cliff R]

I've owned quite a few 55's and a two 51's. I sent all of them down the road but my two Closed Port 55's. The open port versions are still excellent saws, and actually have a broad/smooth power curve and work best with 18" bars in .325".

They outfitted the later "Rancher" 55's with 3/8" and many came with 20" bars. That's a little too much for them, IMHO, but they would still be OK for firewood cutting if you didn't "push" them really hard.

The biggest problem with the CP versions is finding OEM P/C''s for them, NLA far as I know. Most of the ones you find for sale with have P/C issues from either being straight gassed, developed an intake leak, or just never correctly adjusted and ran too lean. One of my CP 55's came from Ebay and smoked P/C. It took a little work but it cleaned up well enough and been working fine for over 15 years now. The other one has a mint P/C. Both see a lot of use here, and have never grumbled once or given me any issues anyplace. Power is excellent for the CC's. CP 55's are basically a "pro" saw that oils the chain all the time instead of when it's turning........Cliff

 

[chuck shelly]

thanks cliff and cus deluxe great info. all I,ve seen for new cp piston and cylinder is hyway and maybe meteor ? has anyone tried these brands? maybe its only offered by hyway. thanks, chuck

 

[Cliff R]

I have zero experience with any aftermarket P/C's so can't help out there. In all cases I bite the bullet and go OEM, if they are available and if the saw is worth investing that much money in.....