Fix Your Inaccurate Compression Tester!

Most compression testers sold in automotive shops—whether to professional mechanics or home enthusiasts—give false readings on the 2-stroke and 4-stroke small engines we repair. This is because they lack a low-pressure Schrader valve in the adapter that screws directly into the cylinder.

Be it this Stihl MS260 chainsaw featured in the video, a Husqvarna lawn mower, or an Echo leaf blower, a compression tester without a low-pressure Schrader is useless—the readings it gives will be wildly inaccurate.

In today’s short DIY tutorial video, I’ll show you how to easily fix this problem by drilling, tapping, and installing the valve into your existing adapter. This quick modification can be done on any tester, and whether you’re rebuilding small engines in your home garage or working as a professional mechanic in a workshop, this modification is essential.

(PLEASE NOTE: Where exact tools I use are no longer available, I have included links to alternatives that I recommend instead.)

TOOLS USED IN THIS VIDEO:
Compression Tester: https://amzn.to/4ixcA5i
Low pressure Schrader Valves: https://amzn.to/4iOcfLt
4.2mm Drill Bit: https://amzn.to/4jEGiGy
4.5mm Drill Bit: https://amzn.to/4jY1mrq
Valve Tool: https://amzn.to/4m3gk1g
Tap Handle: https://amzn.to/4d72lDu
Thread Sealant: https://amzn.to/3GBGuYR
5v1-36 Tap: https://tinyurl.com/33srana3
Mini Lathe: (Select your country below)
US https://amzn.to/41xpquS
CA: https://s.vevor.com/bfRDJX
UK: https://amzn.to/3EWjcMf
EU: https://s.vevor.com/bfRDJF
AU: https://s.vevor.com/bfRDJg

TOOLS I USE:
Engine Tachometer - https://amzn.to/3TE48GZ
Pressure & Vacuum Tester: https://amzn.to/3RlcGlh
Compression Tester: https://amzn.to/4ixcA5i
Induction Heater: https://amzn.to/4imTZd5
Spark Check'r https://amzn.to/433vlY5
Borescope: https://amzn.to/41jqJOb
Gasket Maker - https://amzn.to/4bIiygR
Vessel Screw Drivers - https://amzn.to/3ISewG2
Brass Hammer - https://amzn.to/3xkyuH6
Stanley Stump Vice - https://amzn.to/3waHuOw
Stens 750-120 Carburetor Adjustment Tools- https://amzn.to/4atkBV5
Powerbuilt- backtap - https://amzn.to/49I9305
Forceps - https://amzn.to/4a2ud9v
Zoom Oil Bottles - https://amzn.to/3TWZV2t
Bondhus Hex Keys - https://amzn.to/3J2m8FL
Klein MM400 multimeter - https://amzn.to/3PI3Y02
Stahlwille Combination Spanners - https://amzn.to/3IY6fQI
Milwaukee 12v Impact Driver - https://amzn.to/3VEuxH4
Milwaukee 12v Impact Wrench - https://amzn.to/4aPESVd
Milwaukee 12v 90 degree Grinder - https://amzn.to/4czLiJp
No-spill gas can - https://amzn.to/3TDfWcb

Any links to products are likely to affiliate links and I may earn a small commission from qualifying purchases with no additional costs to you.

WATCH THIS VIDEO NEXT:    • 5 Mistakes You’re Making On 2 Stroke Repairs!  

Yes this video was a collaboration (conspiracy) with another YouTuber:    • I Drilled My Compression Tester! It Worked...  

00:00 Easy DIY fix for inaccurate mechanics compression testers
00:49 Comparing compression testers - with and without schrader valves
01:48 The tools you need to fix your compression tester
02:48 Using a metal lathe to drill out the adapter
03:28 Tapping threads and forming schrader valve seat

#Stihl #Chainsaw #SmallEngineRepair #DIY #Tutorial #tools