When to do a rebuild

[Jeff Torgalski]

Hey all,

I was wondering, since I have been running the HECK out of my Villain since I got it going good, I'm wondering when I should consider a rebuild.

When we are rebuilding engines, what are the most important parts to replace? Bearings? The connecting rod? The piston and liner? How do I know if these are bad, instead of wasting my money on new parts I don't really need?

Thanks in advance,

Jeff

 

[Kris Flynn]

well times have changed hey...i havnt ran my boat for a long time! although i want to run it all weekend long, things just seem to keep going wrong or there isnt enough time in a weekend to do anything!

I finnally got around to glueing the non-trips today! how slack is that? if i knew what setup i was going to run in my radio box, i might be able to drill the holes and stuff, but i dont know just yet so my center section hasnt been glued yet...although i might just glue it now and drill all the holes later on to get it over with.

well sorry for clogging this thread and crapping on, but i thought i would let ya know whats going on

Kris

 

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Most of the time it's the bearings or the PTO bearings that wear out first. Regular maintanince after running your engines will prolong the life of the P/L and the rod. When you replace parts it's usually a good idea to replace the gaskets as those wear out unevenly and cause leaks. I've seen boats w/no compression in the piston run really strong and fast so unless you damage them they don't need to be replaced until the boat loses performance.

 

[Jerry Dunlap]

I think I'd agree that bearings might be the first thing to wear out. Something like connecting rods and crankshafts usually just break - without much/if any warning.

An indication that bearings may be loosing their seal is the motor will not run when leaned down to develop power. This is because air is being allowed through worn out bearings. An easy check for the PTO is simply to pull the unit and spin it between your thumb and first finger - I suppose any finger would work - the little finger seems a bit uncomfortable, however. A bad bearing will cause an uneven spin. The same procedure can be used to check the front end housing.

For piston/sleeve - if the piston can be pushed to the top flange on the sleeve, it's probably worn pretty well.

An easy check for the connecting rod is to place the rod on the crankshaft stub and move the top of the connecting rod back and forth. There shouldn't be excessive movement.

When crankshaft break, at least on 3.5 K&Bs, they usually break just infront of the counter weight where the crank is cut for the intake port. Sometimes a crack can be detected prior to the crank breaking.

Jerry D.