I have a Milton 2-gauge LDT that also has its own pressure regulator. Having the correct size adapter for the VTR plugs was an issue until I borrowed one from engine tire pump kit I never use. Can only do one cylinder at a time by setting at TDC (remove inspection plug in left engine case) and rotate engine in 2nd gear (or turn over with socket wrench after removing center left case plug). Follow instructions and listen at exhaust valve leak at muffler outlet, intake valve leak at carburator, ring leakage at valve cover breather or oil fill hole, and remove radiator cap for bubbles due to a blown head gasket (they also make testers for coolant that detect CO in fluid).

Whereas a proper LDT is best, you can do all of that with an old hollowed out sparkplug with a air nipple welded to it; or create your own plug hole adapter this way. A 2-gauge unit checks differential pressure, thats why it has 2 gages. Line pressure will be higher than the cylinder pressure due to the blowing by the rings, valves and/or a bad head gasket.

When testing an engine, make sure that this test is done right after the engine has been shut down. This will ensure that the cylinders are lubricated, and that all the seals and rings are seated correctly. Follow the LDT's instructions or set the inlet pressure to +90 psi with the built in regulator. The lower gage should not read below 75 psi. Preferred is around 70 to 72 psi and there should no more than 10% difference from cylinder to cylinder (same as with a compression tester, which I presume you already did; both wet and dry). A good engine should not show much over 10~15% leakage, though some prefer less than 5% or even 3% for race engines. Last time I checked my VTR at about 30,000 hard miles (I have used Mobil 1 since wear-in) I had less than 5% leakage and approximately the same differential differential between cyclinders. When I sold my Baby Hawk Gt (NT650) it had less than 5% at 65,000 miles! You gotta love Hondas.

http://en.wikipedia.org/wiki/Leak-down_tester

http://www.xs11.com/tips/misc/misc3.shtml

http://www.engineersedge.com/power_t...sion_check.htm

http://www.globalair.com/discussions...le.asp?msgID=3

 

Have you considered doing a leakdown test? worth a thought

ok, just kidding, anyway, I find these guys writes ups usually useful - good starting point at least

http://www.motorcyclistonline.com/ho...t_motorcycles/

 

thanks. I'd not actually done a compression test. I was told they were useless, but I guess not.
I have a compression gauge but whats is the point of doing one if you also have the LD tester? Or is it just to avoid doing the LD test if compression is good? What is good compression for the VTR?

I read the bit about testing, then spraying 2 ts oil and retesting. Does the bike have to be warm for this also?

 

Oh man. I had a long week and I am pretty tired man. I got so much on my mind. Sorry for the redundancy.