Lesson learned on the cheap AM P&C kits

[calereeves]

I bought an eBay special P&C for my MS361, it was like $70 for the P&C, clutch, muffler, intake and misc other filters/hoses. I figured I'd gamble on it for the price, got it all back together tonight and it blew 125 psi. FML. Going to go order a Hyway setup now. Lesson learned.

 

[rich450es]

i just installed one on a 029 super and compression got better after the saw runs for awhile ( a tank or 2) was at 125 and is getting better its now at 145
(i bought a new compression tester to make sure #s were right )

 

[calereeves]

Ok, I'll give it a chance and saw some junk wood out back to run some fuel through it. I've also got some caber rings I might throw in to see if it's a ring or a casting/machining problem.

 

[rich450es]

the kit i installed sucked ...... all the holes wernt tapped and the square castings where the exhaust bolts go wernt even milled all the way out (i had to use a dental pick and file to get it to work ) but the ring end gap was in spec and the cylinder was round so i guess it will work out but time will tell ....( nothing to loose for $99 the boss spent if we get 6 more months out of it )

 

[treesmith]

I've heard people on here say use Caber rings, the ones with the kits are rubbish

 

[Rookie1]

Ok, I'll give it a chance and saw some junk wood out back to run some fuel through it. I've also got some caber rings I might throw in to see if it's a ring or a casting/machining problem.

Dont get to rash. I wouldnt want to see you give up before you see for sure whats up. Like already said run that setup and check compression then maybe try the cabers. Then let us know the results. Sounds easy for me to say but AS could learn from your expierience.

 

[MrGiggles]

I had a similar issue with a Huztl P/C on my 50 Special. The underlying issue was a squish band that was pretty excessive.. On the second tear down I threw a Caber ring on it and it seemed to help a little. I am also using a base gasket, I tried tossing it and using sealant, but it created an air leak so I put it back in. I did post a thread about it awhile back, with all of my squish measurements and stuff.

My saw runs just fine and cuts pretty good, but I have not tested the compression. For the money I paid I am happy and wasn't wanting a hot rod, just a reliable back up saw. I've got probably 30-40 hours on it now without an issue, mostly running a 20" bar.

I believe that if somebody took the time and cut the squish then checked the port timing these P/C's would run a lot better. There weren't any casting or fit issues on mine, and the cylinder plating was pretty good as well.

 

[angelo c]

I've heard people on here say use Caber rings, the ones with the kits are rubbish

depends on the kits....Cabers come with Meteor kits

 

[broman78]

Get what you pay for no way around it.

 

[heyduke]

i just installed one on a 029 super and compression got better after the saw runs for awhile ( a tank or 2) was at 125 and is getting better its now at 145
(i bought a new compression tester to make sure #s were right )

you're in utah. what's your altitude? 125psi might be fine. 145psi might be great.

 

[jar944]

As already said You need to give it a few heat cycles for the rings to seat before a comp check would be valid.

 

[rich450es]

i am at 5000ft at he door to the shop i work at ......the cylinder porting and plating was done great (smooth and shiney...lol ) it was the threads that wernt tapped ....it was like they forgot a few steps there at the end

 

[heyduke]

i am at 5000ft at he door to the shop i work at ......the cylinder porting and plating was done great (smooth and shiney...lol ) it was the threads that wernt tapped ....it was like they forgot a few steps there at the end

i live at 6000 feet, a little to the southeast of you. at your altitude 125psi is fine, the equivalent of 150psi at sea level. 145psi is very good. take that thing out and play with it. it should make good power.

i've used two different p/c kits that had the same problems as yours, had to drill and tap the holes for muffler screws etc. i figured that the 7 year old kid who made it in his "school" needed a nap. i recently rebuilt a stihl 029 that didn't have sufficient clearance for the crank to turn over, had to attack it with a die grinder. it's working ok now. wish i could find someone who needs it.

 

[jar944]

 

[heyduke]

thanks jar, i have that somewhere but didn't have time to find it. rich's last reading was 145psi which puts his compression at 168psi, sea level, not too shabby.

 

[cus_deluxe]

i have a 51 with a chinese P+C and it rips. Unplated cylinder had visible pores on the walls and was overall a poor quality casting. not sure of compression, but a little time spent with a rasp and file to match intake and exhaust ports to carb and muffler and a bit of emery cloth by hand and it runs like crazy, and still getting stronger it seems with only 5-6 tanks through it. and for $50 its hard to beat. that said it was a free saw to begin with. if it was a saw i paid good money for, i might spend the money on a meteor kit (which i plan to do for my 262 basket case....

 

[pioneerguy600]

All of the AM kitsI have worked with so far had very loose squish and poorly shaped squish bands. Some have rings or ridges in the squish band and combustion chamber. All this leads to poor compression, some were in the .030+ clearance, that`s excessive for most saws. Shaving off the base lowered the squish and brought up the compression 20+ pounds on them.

 

[Landmark]

i am at 5000ft at he door to the shop i work at ......the cylinder porting and plating was done great (smooth and shiney...lol ) it was the threads that wernt tapped ....it was like they forgot a few steps there at the end

they probably built it on Friday.

 

[dumbarky]

I have found on a lot of aftermarket stuff from "the peoples republic" that the threads are missing. Not sure why but they seem to have a quality assurance blind eye when it comes to threads. Or maybe they're just doing it to mess us. Either the threads just aren't there.

 

[calereeves]

I need a couple of minor pieces before I can get to sawing, but I did swing by the dealer earlier to pick up a set of factory rings. They were out of stock, but I did find out that they are $30 EACH, according to the questionable temp counter guy. The good part of the visit, however, was discovering a 1mm base gasket and a thinner, .5mm base gasket. I'll put the .5mm gasket on tonight and recheck the compression, and then do the same with a paper bag gasket.

I planned on this being a quick sell, but I'll turn it into a little science project for the benefit of AS