evinrude 35hp power head swap

[what66]

HI I need some HElp I have a 1958 35hp evinrude lark<br />with bad compression I bought a 1957 35hp evinrude power head off ebay.<br />The problem is my old engine has a thermasta and the other power head does not.<br />other than that the engines are identacal.<br />can I put my head on the new power head so it will have a thermasta? <br />or can I use it as is?<br />any help would be apeicanted.

 

[what66]

Re: evinrude 35hp power head swap

I now realise that the thermasta is part of the block do I have to change the water pump to work with the one without the theam?

 

[what66]

Re: evinrude 35hp power head swap

Oops I was wroung the thermast is part of the head<br />can I use my head from my old 35 on the 35 I just got?

 

[rodbolt]

Re: evinrude 35hp power head swap

I think the block base designes are different on motors with t-stats vs motors without in those years,

 

[jimmbo]

Re: evinrude 35hp power head swap

The engines with stats actually recurculate the water back down to water pump. Because of that the blocks, like Rodbolt said, are differet.

 

[what66]

Re: evinrude 35hp power head swap

so what your saying is I just waisted $150 <br />can I still use that power head as is if it fits?<br />the problem I'm having with the old one is the compressions low it's only 60psi on the botom and 80psi on the top.<br />the power head I got has 125psi per cylder.<br />I did get a starter and a carb and coils from the new one so it wont be a total loss but it's disapointing

 

[G DANE]

Re: evinrude 35hp power head swap

If it bolts on and splines in cranckshaft are the same, I am sure you can use it. Lay them aside and try to compare. Unfortunately I never worked on these years, but several here has, among them Paul Moir, who has lots of experience. I am sure hi will chime in here, just have a little patience.

 

[Paul Moir]

Re: evinrude 35hp power head swap

Thanks for the vote of confidence, but I can't think of anything to be done here. The powerhead base of the Super Quiets is very different from the unsheilded (thermostat-less) Big Twins - which are more like your 25hp. The bolt pattern, location of water tubes - really everything is totally different.<br />Sorry to hear your about your problem!

 

[what66]

Re: evinrude 35hp power head swap

well I guess I should look closer before buying. <br />I did get some good parts off it so it's not a total waist. <br />I guess I can and try to sell it on ebay. <br />let this be a leason to all of you ebayers look closely before you buy.<br />again thank you for your help.