Johson bottem end repair SOS...SOS...

[karlow1]

I had a rod failure on my 1990 40HP. It seemed like the cap screws just came lose. I picked up another power head on Ebay and swaped one piston, rod, and bearing set. Here is the question, I have read in the manual (aftermarket) that a special tool should be used to properly align the rod caps. It warns that if this tool is not used you may experance premature bearing failure or catastrophic bottom failure. How likely is this problem. I was ready to reinstall the power head. What do you use? What the heck do I do now!
Help!

Thanks guys!
KP

 

[Boblester40]

Re: Johson bottem end repair SOS...SOS...

Its is a fact for sure , the caps are cracked apart and do not re align just by bolting them up , however there are several ways of doing the alignment with out the special tool , if you do a search on the forum you will find many methods, I personally assemble the rod and cap on the engine and then apply very slight pressure on the rod bolts and use a finger nail dragged along the edges to check the alignment , small adjustments can be made by tapping the cap into alignment before tightening down , the caps will normally try and spread apart when released so a small clamp is useful to align them where the two halfs meet . do not tighten them down to hard before alignment is achieved as you could deform the mating surface.

I had a 20hp 1999 which had done exactly the same the other week.

rgds
bob

 

[karlow1]

Re: Johson bottem end repair SOS...SOS...

Thanks Bob, that is just wht I need to know to stay out of trouble. So now, I will take it back apart for another look.

KP

 

[wilde1j]

Re: Johson bottem end repair SOS...SOS...

Make sure to use new rod bolts and torque them! If you don't, you're looking at a similar repeat failure.