1969 Johnson 9.5

[wayne h]

Re: 1969 Johnson 9.5

they dont make j4j any more so j4c is the replacments. sorry spelling is not my best subject i meant choke with the cowling on does the engine choke out take her to the lake and run her without the cowling then run her with and see if there is a diffrence in throttle responce. u can also spray water in the lower part of the mid section just under the power head and see if it leaks out the bottom if it does then u know the donut gasket is ripped

 

[lakelover]

Re: 1969 Johnson 9.5

Originally posted by wayne34609:<br /> they dont make j4j any more so j4c is the replacments. sorry spelling is not my best subject i meant choke with the cowling on does the engine choke out take her to the lake and run her without the cowling then run her with and see if there is a diffrence in throttle responce. u can also spray water in the lower part of the mid section just under the power head and see if it leaks out the bottom if it does then u know the donut gasket is ripped

I should have been able to figure that out! Yeah, there is definitely quite a difference on the lake in throttle response with the cowling off.<br /><br />Thanks again!

 

[lakelover]

Re: 1969 Johnson 9.5

More trouble, is there any hope?<br /><br />I was messing with this motor last week. I had the plugs out to check them and saw a fair amount of carbon still on piston heads. I decided to do more decarbing so I screwed in the bottom plug hand tight. I put the wrench on it to tighten it and with very light and almost non-existent pressure, it kept turning and turning. I removed it again (by hand) and the threads from the cylinder head were wrapped around the plug threads. Also I noted that there seemed to be an oil drip coming from around the plugs before I removed them. Would the sorry state of the cylinder head have been causing or contributing to the low compression readings?<br /><br />I read that a helicoil (?) can be put in. Can anyone ballpark a cost on this procedure? I'm really thinking that maybe it's about time to give up on this motor.<br /><br />Thanks again.

 

[wayne h]

Re: 1969 Johnson 9.5

i have a head email me if u are intrested

 

[Paul Moir]

Re: 1969 Johnson 9.5

I expect you could have a machine shop do it for less than $20 per hole. Head gasket is another $10 - and you get a chance to have a look at the cylinders and water jackets.<br /><br />Make sure they use heli-coils. They're stainless which is nice.<br /><br />There's some cheapy DIY rethreader kits out there but they're not nearly as nice as the heli-coil and not much cheaper than having someone else do it.

 

[lakelover]

Re: 1969 Johnson 9.5

Started new post re: carbon build-up question. new post

 

[lakelover]

Re: 1969 Johnson 9.5

Update..I replaced the head and while it was apart, the thermostat. I did a cold compression test after reassembly. Still a low 60-ish but fairly equal. I don't know if it would make much of a difference, but I didn't get to retest compression after the motor was warmed up.<br /><br />With just those two things, it runs a lot better now, starts easier and runs smoother at low speeds, has a little better top end. Maybe next year I'll get a kit and service the carb and maybe replace the prop, but for now I decided to just put it up for the winter.<br /><br />Thanks for all the advice and info!

 

[wayne h]

Re: 1969 Johnson 9.5

glad it worked out for u. are you testing compression at wide open throttle ??? eather way 1 of my 9.5s only has 68 psi and runs like i top so i am not touching it hahaa

 

[lakelover]

Re: 1969 Johnson 9.5

Originally posted by wayne34609:<br /> glad it worked out for u. are you testing compression at wide open throttle ??? eather way 1 of my 9.5s only has 68 psi and runs like i top so i am not touching it hahaa

You know, I probably didn't remember that. I'd only done it once before so forgot to open the throttle. Anyway, I'll test it again, and maybe next year I'll replace the donut that's letting all the exhaust up under the cowl. It does still run better with the cowl off. Thanks.