Cylinder leak down test in an outboard

[kerncat]

Have a 1988 Johnson 70 hp VRO that got over heated by the prior owner..I pulled the head and there is no sign of burning, discoloration, cylinder wall scoring, etc...I notice (have not measured yet) what appears to be some warp in the head..I plan to surface the head and reinstall it with a new gasket...here's my question..If I run a compression test and it is ok is it necessary to run a cylinder leak down test as well? I don't have the tester and don't want to buy one if it isn't necessary...If this were a big money engine to run way off shore with I'd sure do it but for a bay and kelp bed hopper is it a big deal??? By the way, I'm dumping the VRO and going to pre mix at 50:l.

thanks,
Kerncat

[bertram31]

A leak down on a two stroke wont tell you things like on a V-8. Usually a compression test is all you need on a two stroke.

Jack

[bigbrownbuku]

just service the head like you mentioned then compression test. if they are all the same and above 100 you are in business. be sure to service the entiore cooling sustem if it hasnt been done in a year.

[Boatmark]

Once you are done with surfacing the head, torque to 20 ft. lbs. in 3 stages, from the center out. You should be around 110 lbs on compression, with no less than 10% variance between cylinders. Hope this helps, Mark- Also ditch the VRO and go 50-1 premix, VRO is a piece of shit system, problem city!