Got a new compression gauge and tested a few saws

[RED-85-Z51]

Been a long time since i had hard numbers, usually stuff is either good enough to run or obviously very bad.

But i pulled a few down to see. All are cold, and none have run in a month, choke off, full throttle..3 full pulls

MS460- OEM cylinder i restored, meteor piston and caber rings, no gasket...2 tanks thru it. 190psi

MS440- Meteor piston and caber rings, oem jug i brought back...has a gasket.
172psi

MS280, bone stock...untouched top end.
138psi

026 Metal tag, bone stock saw..very low use, last cranked in April. 157psi

Gauge has a 1" hose and the schrader in the tip.

 

[Vintage Engine Repairs]

Very nice mate, I love getting numbers from my saws with mine.

Initially I brought one from a car shop, no shrader valve in the hose, gave really low, inaccurate numbers. Went the total opposite direction spending a decent wack and got a Kincrome version, had 2 shrader valves - One at the adapter that goes in the spark plug and one at the dial. Gives consistent and very accurate readings

The joy of good quality lasts long after the sacrifice of higher price is forgotten.

Ps - some great numbers, especially on the 460 - 190 psi with three pulls.

 

[djg james]

Got a link to your gauge? I could use one.

 

[old guy]

I pull till the gauge stops going up, sometimes 10 or 12 pulls.

 

[RED-85-Z51]

Its a Strandix 1023. 39.99 on ebay, looks identical to the ones echo used to sell to dealers

Sent from my LM-G820 using Tapatalk

 

[RED-85-Z51]

I pull till the gauge stops going up, sometimes 10 or 12 pulls.

These all seemed to peak on the 2nd pull, 3rd may have given a few psi more. I think the short hose contributes to that.

Sent from my LM-G820 using Tapatalk

 

[lone wolf]

I pull till the gauge stops going up, sometimes 10 or 12 pulls.

The hose length requires more when they are longer! Harley stay out of it!

These all seemed to peak on the 2nd pull, 3rd may have given a few psi more. I think the short hose contributes to that.

Sent from my LM-G820 using Tapatalk

Yes the hose length is why no doubt .I aint no fun having to do 12 or 14 pulls with the longer adapter hoses.

 

[cookies]

The schrader valve is the key, a car or truck valve stem schrader valve should fit a compression gauge. Every 4-5 years I change the valve in mine after realizing over time/ handling/use the little stinkers start to stick, the main shaft pin gets bent, they get oil contaminated etc. The schrader valve and gauge are removed and the hose is then able to be used to pressurize the cylinder using shop air, any time this is done I replace the schrader valve. I have been using the same craftsman compression gauge since 1999!

 

[djg james]

Schrader Valve? I don't see it.

 

[old guy]

I pull till the gauge stops going up, sometimes 10 or 12 pulls.

 

[RED-85-Z51]

View attachment 872224
Schrader Valve? I don't see it.

You know its not visible unless you look inside the brass fitting right? It lets air in but not out.

 

[RED-85-Z51]

Ooo i need to go try my 55 and see what it has

Sent from my LM-G820 using Tapatalk

 

[RED-85-Z51]

Not bad for a well used stock 55R

Sent from my LM-G820 using Tapatalk

 

[old guy]

Yeah, I was surprised to see it that high, this one looks to have little time on it.

 

[djg james]

Not bad for a well used stock 55R

Sent from my LM-G820 using Tapatalk

Thanks for the photo; no I didn't know. I'm new to chainsaw repair.

 

[stihl86]

So, short hoses effect #'s, valves effect #'s, number of pulls effect #'s. I would guess how hard the pull is effects #'s. Along with ambient temperature? Mix ratio effects #'s. Brand tool effects #'s. Brand saw effect #'s. Tell me, how can anyone come to the conclusion that their gauge is giving accurate #'s. What should those #'s be? What is the guideline for the results?

 

[lone wolf]

So, short hoses effect #'s, valves effect #'s, number of pulls effect #'s. I would guess how hard the pull is effects #'s. Along with ambient temperature? Mix ratio effects #'s. Brand tool effects #'s. Brand saw effect #'s. Tell me, how can anyone come to the conclusion that their gauge is giving accurate #'s. What should those #'s be? What is the guideline for the results?

Use 3 different gauges and cross check each one with your compressor and you will be able to tell which ones are accurate.

 

[RED-85-Z51]

I tested my freshly rebuilt poulan 4218A at 112psi...so i trust its not reading high or anything..110-115 is about par on the plastic transfer poulan models.

Sent from my LM-G820 using Tapatalk

 

[PV Hiker]

So, short hoses effect #'s, valves effect #'s, number of pulls effect #'s. I would guess how hard the pull is effects #'s. Along with ambient temperature? Mix ratio effects #'s. Brand tool effects #'s. Brand saw effect #'s. Tell me, how can anyone come to the conclusion that their gauge is giving accurate #'s. What should those #'s be? What is the guideline for the results?

You can add what elevation you are at when testing.
.

 

[old guy]

Hard & fast rules do not seem to apply, I had a 350 husky with a 346 cyl on it & decided I needed a stock 350 and put the 350 back on, first comp was only 88 or89 lbs, but started rite up & ran well, after a couple of heat cycles comp was up to 104, after running it some comp is now 118 which I think is 10 or 15 lbs. low for this saw.
I pulled it down last week to check ring gap, it is .013, should not be a problem.
I've also got a poulan wild thing that's hard to pull over, It reads 154 on the gauge, I don't see that starter lasting long.