90 Hp Johnson,Need proper sea foam process

[mrtool2u]

I know that this topic has been beat down like a rented mule,but I just picked up this motor and I sure would hate to screw up my motor.I checked with the local Napa and they only have the liqiud version ,so I am locked into using that.After some research I saw a post that said to mix 16oz with 3/4 gallon gas and 3oz oil and run into main fuel line,run for 15 minutes 3 times in a row and presto,clean motor.Is this the best way to do it,or is the a more efficent way.Any and all info much appreciated.

 

[ob]

Re: 90 Hp Johnson,Need proper sea foam process

What year is your 90 hp?

 

[mrtool2u]

Re: 90 Hp Johnson,Need proper sea foam process

I was told 1986,but the sticker is not on the motor,,is there another way to find out.It looks to be mid 80s.

 

[ob]

Re: 90 Hp Johnson,Need proper sea foam process

Reason I was asking is that many of the later models that have the key switch activated solenoid primer have a schrader valve on the red lever of the solenoid primer for this purpose.You can inject engine tuner or fogging oils into the schrader.

 

[mrtool2u]

Re: 90 Hp Johnson,Need proper sea foam process

I do not have the schrader valve,but my brothers 1995 Evinrude 115 has it,,looks th be a little easier process.

 

[ob]

Re: 90 Hp Johnson,Need proper sea foam process

They are real handy.Tell you the way I would do it is to run the engine on the hose until it up to temp.Shut down.Remove the sparkplugs .Inject some OMC engine tuner or equivelant into each cylinder that is at BDC distributing it so that it coats the entire cylinder wall of the pistons at BDC and turning the flywheel by hand until all cylinders are done the same way.Then turn several additional revolutions to distribute the product and let set overnight.Fire it off the following day and preferably get it up to speed in the water to blow out all of the dislodged carbon and crud.This is a decarbing process targeted specifically to clean cylinder bores,piston heads and ring grooves.<br /><br />For the fuel system ,fresh 87 octane with a shot of sta-bil in the tank and run through carbs works for me before putting up for 3 weeks or more.If run regularly ,just fresh 87 octane and TCW3 oil.