25 johnson ....here we go...up date

[jims plan b]

Alright let me get started ...I have a 25 johnson model number 25R76E I have no idea how long it has been sitting but it is a clean as the day it was new. I have installed a new impeller and spark plugs and have ordered a fuel pump kit and a carb kit.

just for fun i tried to start it to day... it scared the hell out of me when it started on the first pull (that was the last thing i expected ) Now... it will only run at a fast idle and will only run for about 2 minutes then shut off abruptly and will not restart right away. The heads are not to hot, I can place my hand on them and hold it there.

there is spark on both plugs but the lower plug does not seem as strong as the top plug I ran it for several min. then after it shut down i pulled the plugs ...the top plug is brownish black and dry and the lower plug is clean and wet.
I also noticed a very small water leak at the head gasket just below the half way point and above the lower plug on the left side.

i will install the fuel pump kit and rebuild the carb when the parts come in and see what happens from there but the spark plugs and the water leak is a concern .....any thoughts ?
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Ok i got the head off with just one bolt giving me some trouble. cleaned every thing up and am ready to put it back togeather. There was a small amount of water in the lower cylinder is the head the only place that it could leak into the cylinder or could it be invaiding from the exhaust side as well ? I will also need to know what the torque is on the head bolts ...the carb rebuild will be done tonight as well as the fuel pump kit...I think i am gaining ground on this thing with a little help from my friends on here ...thanks for the help

 

[HighTrim]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

Water in the cylinder is a big concern yes.

Check the compression to start. Then go from there.

 

[jims plan b]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

is that what would cause the lower plug to be clean ?

 

[Beek14]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

If one plug is getting better spark than the other one, that can cause a difference in plug conditions. Present water can as well. Got to get that head gasket replaced.

 

[jims plan b]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

being that it is a 1976 should i try it my self or take it to the shop ?..my fear is breaking a bolt although all the bolts and screws that i have remover so far have come right out ....it has only run in fresh water

 

[Beek14]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

If you're careful, you should be able to do it yourself. No matter who does it, if the bolt is bad it's a little inevitable. However if it has been taken care of and what you have taken out are backing out, it should be fine. I've done head gaskets on models older than that before no problem.

 

[jims plan b]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

i just ordered the head gasket and while i was at it i got the exhaust cover gaskets as well ...in for a penny in for a pound

 

[jims plan b]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

bumped up with the update

 

[Beek14]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

Water only runs from the impeller through the exhaust housing, up through the cylinder head, and out the water tube (tell tale). Unless you have the hood off, and are getting water into the engine area where it could possibly be entering in through the exhaust ports (with a bad gasket), the only place it could be coming from is the cylinder head. The gasket should take care of it.

 

[AlTn]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

water could be entering from the inner exhaust cover gasket area as well..less likely than the head gasket..does your motor have a tell tale?

 

[scrit9mm]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

+1 on the compression test. Double check that you have the right sparkplugs then replace them!

 

[jims plan b]

Re: 25 johnson ....here we go

Re: 25 johnson ....here we go

water could be entering from the inner exhaust cover gasket area as well..less likely than the head gasket..does your motor have a tell tale?

no tell tail on this one.water exits throught the exhaust...i will have it togeather tomorrow night and let evey one know what it does