1976 Johnson 135hp v4 (bubble back) thermostat access???

[jhouse]

how do I access the thermostat on my 76' Johnson 135hp v4 bubble back? The seloc manual just says to remove the covers, but I dont see how I can remove the lower cowling without taking of the power head...Im sure you can service the thermostat without taking your entire engine apart. The manual is very vague.......please help...THANK YOU

 

[emdsapmgr]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

This is a task which will frustrate you and skin your knuckles. You can loosen the bolts which hold the lower cowling. It won't move much, but you may get it to move up to 1" or so. Just enough room to get a 1/4" drive socket and swivel onto the heads of the 3 bolts. As difficult as it is, it's just as hard to get the assembly put back on. The flat rate is something like 3 shop hours. A good technician will not need to pull the powerhead. Plan on spending every minute of that time to do the repair.

 

[ryguy1101]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

....and pray your corrosion is minimal so that the bolts come out without snapping... I've only disassembled about 5 of them, but 4 of the 5 were frozen nightmares. I strongly suggest soaking the bolt heads in penetrant and introduce some heat/cool cycles prior to attempting this project. Hopefully yours have been serviced a time or three since manufacture in '76!

 

[AEROCOOK]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

When I did the T stats on my 1988 V4 bubble back I removed the bubble from the back of the motor, dont know if I needed to but it sure afforded me a lot more working room and visibility.

 

[jhouse]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

Thank you all for your input and advice, you are greatly appreciated! Its frustrating that something that requires routine maintenance is so difficult to access. Design flaw

 

[BKS72]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

I cut an opening in the cowling with a die grinder and then made some aluminum tabs and riveted the piece of the cowling back on when I was done with the 'stats. I siliconed around it as well. I know that's not the right way but the finished product looks nice and neat and it makes it a whole lot easier to get to the stats. I could have done it without pulling the powerhead but it didn't look a fun job.

 

[jhouse]

Re: 1976 Johnson 135hp v4 (bubble back) thermostat access???

I might go that route if I have too much trouble. At least that way you have easy access for future maintenance. Great idea, thank you for the tip.