Importance of vacuum/pressure testing

[barfer]

Most here will understand this but I feel somewhat obligated to reiterate the importance of vacuum/pressure testing small two stroke equipment. Just sold a top end job on a mtronic 362. Don’t throw parts at anything before you know how it failed.
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PS apologies for the long ranting. Sunday afternoon here and I was *literally* waiting for paint to dry. I’ll try to reel it in…

Apologies to OP BallisticDoughut I don’t mean to undermine the point he was making in this thread—which is an *excellent* point and I ++++1 it wholeheartedly.

 

[Joe Crow]

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Where can I get or what is the name of the tool you use to screw into the spark plug hole?

 

[barfer]

Where can I get or what is the name of the tool you use to screw into the spark plug hole?

The Stihl compression tester is usually around $100 US. I just googled what it looks like and the part # for it. It’s an excellent excellent tool but it will only work on small motors—if you want it for measuring compression in cars or motorcycles or whatnot it probably won’t be able to reach the spark plugs. But for chainsaws and small motors there is no “better” tool on earth:



For less than 20 US dollars you can buy one in any auto parts supply store or from Amazon if you search for “compression tester”

I just found this one on Amazon for 14 US



If you buy the 14 dollar one the instruction manual will tell you that you can skip inserting the threaded fitting into the plug and simply push the rubber nipple attachments to the plug hole firmly—the ones in the top half of the red box above. I would STRONGLY suggest never to use the pressure fit rubber nipple connection method—always always always thread the gauge into the plug hole. Those press-to-fit will never give you any consistency in the results because they fail to create a seal.

I’ve never used the inexpensive ones but I’ve seen them used plenty. Mine isn’t made by Stihl but it’s one that actually cost more and is of the same quality.

Good luck fella!

 

[ballisticdoughnut]

Another one. MS500i top end job sold.

 

[hotshot]

Where can I get or what is the name of the tool you use to screw into the spark plug hole?

Husqvarna has one #503 84 40-02, but also chinesium types are cheaper of course.

 

[J D]

Where can I get or what is the name of the tool you use to screw into the spark plug hole?

You can knock the guts out of a spark plug & JB weld a hose barb into it.
I think @Vintage Engine Repairs did a post on making them like that

 

[Bob Hedgecutter]

You can knock the guts out of a spark plug & JB weld a hose barb into it.
I think @Vintage Engine Repairs did a post on making them like that

Repeating what has been done for decades- possibly even made a video.

Can dispense with the nipple and epoxy a bit of silicone tube into the old sparkplug remains- pump plugs directly in to.
Plenty of ways to skin a cat.

 

[barfer]

Repeating what has been done for decades- possibly even made a video.

Can dispense with the nipple and epoxy a bit of silicone tube into the old sparkplug remains- pump plugs directly in to.
Plenty of ways to skin a cat.

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I remember making one of those in high school with JB weld… LOL… it worked great!!!

 

[Vintage Engine Repairs]

You can knock the guts out of a spark plug & JB weld a hose barb into it.
I think @Vintage Engine Repairs did a post on making them like that

Thanks for the shoutout mate!

 

[J D]

Thanks for the shoutout mate!

No worries, you keep posting good stuff & I'll keep shamelessly plugging it

 

[djg james]

I've never done one yet, but is there any advantages/disadvantages using either the spark plug port or removing the carb and using that?

 

[Bob Hedgecutter]

I remember making one of those in high school with JB weld… LOL… it worked great!!!

Yep and let m e guess- high school preceded youtube?

 

[barfer]

Yep and let m e guess- high school preceded youtube?

Grin. High school pre-dated YouTube, the internet, cell phones, CD players… the whole bit

 

[barfer]

I've never done one yet, but is there any advantages/disadvantages using either the spark plug port or removing the carb and using that?

Uh in addition to a lot of other things, pulling the spark plug requires one tool and takes less than sixty seconds… while removing a carb is a much more involved endeavor… (shrug)

 

[Vintage Engine Repairs]

I've never done one yet, but is there any advantages/disadvantages using either the spark plug port or removing the carb and using that?

A side note, but on topic - avoid blocking the intake with rubber between the manifold and carb. Often the manifold warps and causes a leak that gets sealed by the rubber. Always use the correct block off flange. I have 1 which fits 95% of the machines I work on. I’ll find a link shortly.

 

[djg james]

A side note, but on topic - avoid blocking the intake with rubber between the manifold and carb. Often the manifold warps and causes a leak that gets sealed by the rubber. Always use the correct block off flange. I have 1 which fits 95% of the machines I work on. I’ll find a link shortly.

Good, short to the point video. I didn't know The manifold had to be blocked off if the carb was left on. So, so you say NOT to use rubber between intake manifold and card as done in the video?

 

[James Sawyer]

Where can I get or what is the name of the tool you use to screw into the spark plug hole?

I just used old spark plug, ground off the flare that hold the porcelain in. Removed the Porcelain and tap with 1/8 NPT and screw in a brass nipple.

 

[Vintage Engine Repairs]

Good, short to the point video. I didn't know The manifold had to be blocked off if the carb was left on. So, so you say NOT to use rubber between intake manifold and card as done in the video?

Thank you! I don’t recommend it now, no. I have had a few friends and noticed people online too, can get false readings from doing so and it can cause you to chase your tail. If at all possible, purchase yourself a proper block off flange. I’ll make an update video at some point.

Lots of people still use rubber there, but it’s just something that can possibly set you up for missing a possible leak. The only place to really use rubber is between the exhaust port and muffler.

Lots of people still use rubber in the intake, but I tend to stay away from it wherever possible.

Hope this helps

 

[djg james]

Thank you! I don’t recommend it now, no. I have had a few friends and noticed people online too, can get false readings from doing so and it can cause you to chase your tail. If at all possible, purchase yourself a proper block off flange. I’ll make an update video at some point.

Lots of people still use rubber there, but it’s just something that can possibly set you up for missing a possible leak. The only place to really use rubber is between the exhaust port and muffler.

Lots of people still use rubber in the intake, but I tend to stay away from it wherever possible.

Hope this helps

What about removing carb and placing O-ring larger than opening of intake backed by a metal plate held in place by the carb mounting bolts?