Logo
FULL SITE MENU

j140tlcte Powerhead Reassembly

S

slimjohnson

Member
First time doing this. I have FSM and good understanding of what I'm doing but have never done one of these motors. Any tips or nuances that i should be aware of. Any feedback would be appreciated. FYI #4 Cly water jacket plugged up at water deflector and melted piston and broke the rings.
 
Get the crank checked for straightness, a pair of v blocks and a guage.

Check the rods for the same.

Check all bearing surfaces for pitting or other damage.

All new bearings.

Get the holes bored and the correct pistons, don't go with your old ones or a simple hone.

Use new deflectors in the heads.

Use Gel-Seal on the crankcase halves.

Torque the rod caps carefully. Check all four corners with a pick to make sure they are set correctly.


Set the pointer for the flywheel to absolute TDC on the new rebuild.
New thermostats. New Waterpump. New carb kits in CLEAN carbs. Check the fuel system for vacuum and cleanliness. Verify idle and W.O.T timing.
 
Meant to say, this is our procedure for rebuilds at the shop I work for. We build remanned powerheads for the industry. We have a good track record with this formula.

If you want to cut corners, then you will reap the rewards.
 
thanks hondamech for the advice. I got a good grasp on the rod caps. Any paticular brand or type of gelseal that you would recommend or is gelseal the name brand?? HAHAHAHA Daselbe.
 
A 1/16" diameter bead is all you need -----------Loctite 518 or OMC / BRP factory " gel seal " is the stuff to use.---------This MUST be a metal to metal joint and some sealers have too much filler material.----You hope that almost all the sealer squeezes out to get this metal to metal air tight joint.-------------It must a be metal to metal fit to properly clamp up the bearings !!
 
I use a carbide scraper, then a file ( carefully ) to make sure there are no bumps of any kind.--Then I use #400 paper to go over the entire surface to make sure it is clean.----------Have taken motors apart and measured the film of sealer to be 0.008" thick, indicating that the previous rebuilder had no idea of what they were working on !!
 
Last edited:
Ok...good to know...but I just use a scotchbrite rollock blue on a 1/4 inch die grinder and polish it off.

To me, it just isn't that critical. Just don't dish out the flange with the rollock.....

Maybe use acetone to get the majority off first.....then the rollock.....just be easy.
 
This is " critical ".-------------Any air leakage between crankcases will result in poor idle quality.------------After all a 4 cylinder outboard like this is really 4 seperate engines with a common block and crankshaft.--This is where care must be taken to get it perfect for proper bearing clamp-up and no air leakage between crankcases.---------------NO POWER TOOLS NEEDED HERE !!
 
I see your point. But note that I said "be easy". I don't grind away at it....i just turn the air down, and easily polish it off...
I haven't had a problem...well...yet anyway.

Do it the safest way you can, and don't dish out the flange or create low spots between cyls as racerone notes.

Oh yeah, and I really shouldn't have said "not that critical".....it is.
 
sound like i need to get really clean and use just enuogh sealer to create an EXTREMLY thin film when surfaces are mated together. I got it.
 
Last edited:
Back
Top