1955 7.5 hp whats next?

[cvflats]

so i rebuilt the carb on my engine and i am wondering if i should put it on and see if it cranks or should i open the block and look at the pistons? i have a book to do it but i am just curious. probably a dumb question

 

[steelespike]

Re: 1955 7.5 hp whats next?

Do a compression check.100 psi would be excellent 60 psi will run fine.
Good compression will give an idea of the rest of the motor.If the head is discolored from over heat you could remove the exhaust cover and check the condition of the postons and bore.You might check the rest of the fuel system before running it.If it sat around alot it could be gunked up.

 

[jbjennings]

Re: 1955 7.5 hp whats next?

What's next will almost positively be the ignition if you haven't done it yet. Have you checked the coils, cleaned and adjusted the points? Those ignitions usually need some work if they haven't had some in a while. I don't see too many small omc motors myself that had compression so bad you couldn't get them to run pretty well. I'd definitely check it, though.
BTW, I have one too and like it.
Good luck,
JBJ

 

[cvflats]

Re: 1955 7.5 hp whats next?

im glad to hear that you love yours. i can't wait to get mine running. I don't think that it was run much or it must have been tuned sometime in its 50 yr life because the coils and condensors dont look too bad. I will definately clean them and make sure the points are set correctly. I was thinking i would see if the spark plugs sparked before I ordered more parts. The head looks fine from the outside but i was considering changing the gaskets for good measure. what are you thoughts?

 

[samo_ott]

Re: 1955 7.5 hp whats next?

Check for a good strong blue spark and check the compression... that will tell you loads of what to do next.

 

[jbjennings]

Re: 1955 7.5 hp whats next?

I don't know what to say about the heads.... For a while I didn't even consider changing the head gasket because you risk breaking a head bolt on a motor that old. But, I had a couple lately that needed the water jackets cleaned. Here in Louisiana in the summer time, you better have that water flowing PERFECTLY if you're motor is going to stay cool with the lake water at an 80 degree temp. Myself, I would get it running first and see how well it cooled before changing the head gasket. If the head gasket is leaking you will be able to tell most likely by looking at the plugs. You will see a little milk on them if there's water getting in there, or the plugs will be steam cleaned. If you do decide to change the head gasket and break a bolt, don't get worried but post back and someone will give you a good procedure on how to get it out without ruining your motor.
One last thing, don't be fooled if you see spark but it doesn't run right wide open. that spark needs to jump a 1/4 inch gap at least or you can bet it's going to run like crap. Here's a pic of my son running mine; thought you might like to see what you have to look forward to. About 14 or 15 mph is what I get with mine.
Good luck,
JBJ

 

[jbjennings]

Re: 1955 7.5 hp whats next?

I just had to mention--it's great on GAS!!
JBJ

 

[cvflats]

Re: 1955 7.5 hp whats next?

what is a good website for parts? i need a fuel filter element gasket for the carburetor and my rebuild kit did not have that gasket. thanks for all the help.
Harrison

 

[jbjennings]

Re: 1955 7.5 hp whats next?

laingsoutboards.com is a good one. also I hear ishop.marine is good. Of course iboats too, but I have a lot of trouble navigating it and you need part numbers. The easiest for me is to just call up the guy at laings. He's helpful and ships fast if he has it in stock.
JBJ