sledfvr said:
how do I do a leakdown test, and what tools do I need. Also my compression testor doesn't fit that small of a spark plug hole. I guess I need an adapter. Sled runs like crazy seems to have lots of power.
You will need a Motorcycle compression gauge and a leak down tester and a compressor with at least 100 psi.
A number of people have asked "What is a LEAK DOWN test?" and "Can I do it myself?". First, let me explain the concept. We already use a compression test to determine an engines condiditon. the problem with this test is that there are too many variables. It can only be used to check engine condition by comparing cylinders to each other or a past norm. Variables such as cam profile, engine cranking speed etc, will affect the readings.
A leak down tester uses air from a compressor and measures the rate at which it leaks through the engine. This is done with the engine not running and the beauty of this is that toy can find the source of the leakage by listening for the escaped air.
Tools need are a leakdown tester, and an air compressor. The tester is available from Milton at about $60.00. Compressor should be at least 2hp and deliver 100psi.
Procedure: Remove spark plugs. Set engine to TDC #1. Calibrate test gauge per the instructions. Lock engine so it can not turn. Conect hose to spark plug hole, Conect pressurized gauge to hose connection. Read leakage and listen to the carbs, exhaust pipe and crankcase vent to dertimine where the leaks are.
Do same test on rest of cylinders. Remember to set TDC of each piston for compression stroke.
This place is right around the corner from me
http://www.tools-plus.com/milton-s1257.html
Ted.