Compression tests

[kram]

43 minutes ago, AHPP said:

You pulled off a cylinder with poor plating and that the studs had pulled out of and replaced it with a £130 one that makes 120 psi. Your saw is still worth £40.

 

"Why it only makes 120 psi" is the question, as the quality of the Meteor kit is supposed to be good. I'd suggest I have done something wrong hence why I am asking. Why must you be a massive dick about it? Go away.

 

The studs were my own fault, I had the exhaust off before and clearly not tightened it properly. The studs did not pull out just like that. When I noticed, one bolt was gone, never to be found again but the threads were sound. I did not have a spare. I re tightened the single bolt and continued the job.. That is why it stripped, then I  swapped it to the other side, finished the job.

A simple 5 minute helicoil will have it repaired good as a new one.

 

 

27 minutes ago, pleasant said:

Poor plug threads in the cylinder, leaking carb or manifold, rings not correctly fitted and to a lesser extent crank seals leaking??

The tester holds pressure over multiple pulls so Im thinking it can only be the rings/cylinder seal. The crank seals, intake and exhaust are not going to affect the psi? - thats not to say all is good with them.

 

 

[pleasant]

I appreciate this is top end stuff, but all should be taken into consideration for the wider picture.  What compression tester are you using...it is known to you to be accurate?

[spudulike]

A decent 372xp will make 170psi cold if pulled over multiple times. A well used one will make 150+. If you drop the base gasket on one, expect around 185psi.

No idea on your Meteor kit, I would have expected it to be 150+. I had a low compression reading on a 372 wearing a stone cutter 375 cylinder but that turned out to be due to the design of the combustion chamber on the larger cylinder.

There isn't much that can go wrong, ring end gap, piston to bore fit, decomp valve.

If the cylinder is dry then expect compression to increase dramatically once there is fuel oil mix around the ring and piston.

I think the Meteor cylinders are rebranded Hyway cylinders.

[kram]

It is possible that I could have pressed the decomp button accidently, not that I remember to press it any other time!

I'll try again tomorrow!

Piston, bearings, pin, and everything was well oiled with 2t for reassembly.

 

I dont think its a Hyway as there Korean, it all said made in Italy on the boxes. Hyway use different type of plating, this looked like nikasil, not that I have any expereince comparing them, but from photos, they look different.

 

@pleasant Yes it should be, Husqvarna OE one thats recommended by many and sold by LSE, results seem accurate and consistent.

Compression Tester - Genuine Husqvarna Part - 531 03 16-86 | L&S Engineers

WWW.LSENGINEERS.CO.UK

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Compression Tester for Husqvarna Machines Genuine Husqvarna Part. OEM No. 531 03 16-86

 

 

Edited Monday at 20:28 by kram

[spudulike]

I had two 440 kits once, one Hyway and one Meteor, both had a badly formed inlet port in EXACTLY the same way hence my comment.