35 johnson died

[Vengel]

I was running at full throtle when my 1983 Johnson died. (pump was working, I don't believe it overheated) When I pull the rope its very jerky and the engine rocks like its off balance or something. Removed the head. Starter rope pulled smooth with the head off. Replaced gasket, put head back on and the rope pulls jerky again. Where do I go from here? Would appreciate any suggestions.

 

[rickdb1boat]

Re: 35 johnson died

Hi Vengel<br /><br />I'd run a compression check on it first to see if there was any major damage done. Then go from there......If you remove the spark plugs, will it pull smooth?

 

[Vengel]

Re: 35 johnson died

yep it pulls smooth with the plugs out.

 

[Vengel]

Re: 35 johnson died

Will do compression test as soon as I get a gauge. Whats "normal" compression for 1983 35 johnson? Thanks for your attention.

 

[BoatBuoy]

Re: 35 johnson died

Sounds like you lost compression on one cylinder. Pressure should be > 100 lb. (my opinion) and the cylinders should be within 10 percent of each other. There are no published specs for number of pounds of compression.

 

[Vengel]

Re: 35 johnson died

OK so the compression tests out at 120 psi on the top and 115 on the bottom cylinders. It takes 6 or 7 pulls to get the max reading. But it sure pulls rough and hard. Any ideas for next steps?