How to tell if hpi baja motor has good compression

[sAvageXl]

Hi guys,
just seeking the help of more experienced people out there, and I wanted to know ways to test and know whether or not a motor has good compression. My dads old baja has been sitting around for quite a while now and he used to drive it pretty hard i.e: emptying the tank at full throttle. I took it out the other day and opened the engine up. Everything seems nice and clean and coated in oil, but the piston had a bit of carbon buildup on the top. Is this normal and how should I test for good compression. Thanks a bunch.

 

[cbaker65]

Hi guys,
just seeking the help of more experienced people out there, and I wanted to know ways to test and know whether or not a motor has good compression. My dads old baja has been sitting around for quite a while now and he used to drive it pretty hard i.e: emptying the tank at full throttle. I took it out the other day and opened the engine up. Everything seems nice and clean and coated in oil, but the piston had a bit of carbon buildup on the top. Is this normal and how should I test for good compression. Thanks a bunch.

Carbon build up is normal for a two stroke that has an oil mixture in the gas , I wouldnt
check for compression ,best way is to run it!..

 

[Chubaka]

I too wouldnt test it if it runs fine. If you still want, the best way I found is a compression tester.

https://www.ebay.com/sch/i.html?_nkw=compression+testor&_trksid=p2380057.m4084.l1313

If your worried about carbon build up, find a cleaner oil.

 

[sAvageXl]

Carbon build up is normal for a two stroke that has an oil mixture in the gas , I wouldnt
check for compression ,best way is to run it!..

yeah I thought so, just wanted to make sure. Thanks for the help and she still rips btw, even on old fuel as I've just discovered.

 

[WoodiE]

I too wouldnt test it if it runs fine. If you still want, the best way I found is a compression tester.

https://www.ebay.com/sch/i.html?_nkw=compression+testor&_trksid=p2380057.m4084.l1313

If your worried about carbon build up, find a cleaner oil.

Yup, this would be the best way.