1964 40 hp johnson blown gasket

[cluke3]

will a blown intake gasket cause low compression and poor idle

 

[Paul Moir]

Re: 1964 40 hp johnson blown gasket

It would definitely make for a poor idle, but low compression would only come in time due to running lean. There would be evidence on the spark plugs, and the WOT RPMS would be down for a while.<br /><br />Sorry, cluke3, but I had missed your last post. I agree with lark2004 though and that's a mid-late 60s engine there. Given that it's setup for the later fuel pump and has the hot-air choke system, that it's white, and that it's round-base that limits it to '64-'66.

 

[cluke3]

Re: 1964 40 hp johnson blown gasket

thanks paul maybe i can get a good running engine out of these 2 just bought this one on e bay for 25.00 guess i did ok has good conpression<br />and turns over ok. the one with the blown gasket has 70 psi in both cyls would not idle

 

[Paul Moir]

Re: 1964 40 hp johnson blown gasket

70psi is definitely on the low side for one of those. Frequently I find extremely bad carbon build-up causing rings to stick in their grooves. Soaking the cylinders with decarb might get them freed up and restore compression & idle.<br /><br />'Course, you could just bolt the good one on and make the other one a science project.

 

[cluke3]

Re: 1964 40 hp johnson blown gasket

think thats what ill do already did a decarb did not help much thanks for all the help.