1992 115 Johnson V-4 Bubble back exhaust

[fgz]

Recently replaced the Power Head with a rebuilt block ( out to the crank halves). Installed new reeds, went through carbs twice, checked the recirc valves and they flow one way only, timing,synk and link all correct per service manual. Double oiling (25:1) for break in and she does not want to restart after running and warm! The symptoms are like its loading up at idle. I have not checked jetting in carbs yet. My question is, does anyone know what the crankcase pressure should be at the recirc check valves in the intake manifold while idleing?

Thanks

 

[boobie]

Re: 1992 115 Johnson V-4 Bubble back exhaust

I don't know of any c/c pressure specs published but when it won't start , check your spark. Should jump a 7/16" open air gap on a spark tester when cranking. You may have ignition probs when it warms up.

 

[emdsapmgr]

Re: 1992 115 Johnson V-4 Bubble back exhaust

What rpm's does the engine idle? Possible the idle is too low, combined with the double oiling-could be the problem. The engine idle should be set when the engine is sitting normally at rest in the lake, in forward gear. Set the idle between 650-700 rpm's. You can also check spark on each plugwire with an inductive timing light when the engine is running. The flashes in the gun will show you if that wire is missing, or has weak spark.

 

[fgz]

Re: 1992 115 Johnson V-4 Bubble back exhaust

Thanks Guys for the advise! I will check all possibilities given!