Getting ready to work on the 140

[interalian]

About to put the heads on. Gaskets don't say "USE NO SEALANT" (pics show both sides) and the old '82 Service Manual says to apply OMC Gasket Sealer 317201 unless gaskets are marked to not. Hmmm, what to do?



And brickbats to OMC for bolt accessibility on the bubble butt. Got it all on and torqued though. Sure glad I put the thermostat housing on before. I was going to put it on before dropping the powerhead in place but didn't.



Particularly this bolt - had to finagle it in whilst prising the motor cover down and avoiding getting sealant all over my fingers.

 

[jimmbo]

Just put the thinnest of coats of the sealer on the gaskets. Don't go by the usual 'if enough is good, more is better, and too much is just right'

Make sure the heads aren't warped

 

[interalian]

Just put the thinnest of coats of the sealer on the gaskets. Don't go by the usual 'if enough is good, more is better, and too much is just right'

Make sure the heads aren't warped

In my industry (electronics), so many techs go by the mantra "the bigger the blob, the better the job". Might be OK if you're soldering a battery lug but not on a fine pitch surface mount chip.

The heads have been surfaced flat and a fair amount of material was removed to get them so. If I run into problems from too-high compression, are there thicker gaskets available? Or just dial the timing back a couple degrees? For the amount this runs, the extra expense for premium isn't a burden.

 

[jimmbo]

There are thicker gaskets available. Now to start looking for them. I remember in Electronics 10(grade 10) guys melting blobs of solder, sticking wires into them, and presenting to the instructor as a completed exercise, then wondered why the teacher was rolling on the floor laughing

 

[Faztbullet]

1) Use NO sealer at all.... 2) Shaving heads do not increase compression on a crossflow, you can safely shave up to.030 with no problems

 

[interalian]

1) Use NO sealer at all.... 2) Shaving heads do not increase compression on a crossflow, you can safely shave up to.030 with no problems

Good to know. Heads not on yet.

 

[jimmbo]

Shaving heads do not increase compression on a crossflow, you can safely shave up to.030 with no problems

reducing the Combustion Chamber volume on every other engine design raises the compression ratio. How is a the crossflow different?

 

[Faztbullet]

On a crossflow when you shave head all you are doing is placing piston eyebrow closer to top of head and you might get 1-3 psi increase. To increase compression you increase the deflector size in head which reduces the combustion area in head. See pics below as Hi compression head has thick rounded deflectors and stock have skinny defectors..

 

[interalian]

Good to know.

Now, all these x-flow motors have a timing pointer that's adjustable. Any 'tips' to zero it? I'm combining the crank case and intake from two different motors.

 

[interalian]

Dressing the engine. Today it's ignition bits. But the coil for #4 is fighting me. Original orientation on the 90 was with the plug wire pointing forward and next to the exhaust housing, but that interferes with the bubble butt on the new motor. I scavenged the bracket off the scrap cowl to make some tests (he he he).

There are only two ways it'll mount and not interfere with the cowl latch bracket - which is better?

a) Plug wire points rearward and sits next to the latch. The latch body looks like it'll be pressing on the coil housing if I go this way.



b) Plug wire points forward and exits near the head.



Open to suggestions.

 

[interalian]

And although I'm getting a bit ahead of myself, here's my test bucket. Local shop re-purposes industrial 55gal plastic barrels (this one had bleach in it originally) and they sell them rinsed for $15. Deal!

Left it cut as tall as possible with a notch for the motor bracket to help deal with splash. And yes, the prop will be off lest there be any temptation to spin it and carve out the barrel.

 

[interalian]

https://youtu.be/aDwttmHO1Gg

It's alive. Started on the second crank too. Promised myself to have it running by the end of May, so that's done. Just need to tidy up the wiring and tweak the carb adjustment. Might need to find some new 140 carbies as these have some play in the throttle shafts. Still, seems to run pretty rich at idle despite some unmetered air getting in. But I suppose that could be a load of needle bearing grease it's trying to consume.

 

[jimmbo]

Nice to see it running. Why have you got the idle reliefs taped over? Not sure but it looked like the garage door was closed. If so, open it before the sound of that engine purrs you to sleep

 

[interalian]

Nice to see it running. Why have you got the idle reliefs taped over? Not sure but it looked like the garage door was closed. If so, open it before the sound of that engine purrs you to sleep

Not taped over, I just put a shield over to deflect the spray into the barrel as I didn't want it all over the garage floor. And that's the back door to the garage - double in the front and a single into the back yard. Makes it handy to pull the trailer straight through.

Like my dual pissers?

 

[interalian]

Something interesting to note: I drilled out the thermostat bypass holes at the suggestion of a number of posts here. Didn't go a whole lot larger than standard but the motor appears to over cool at idle as the head temperature was steady at about 110F according to my infrared whatsit. I expect it will run hotter with some load. We're not into trolling, so I doubt it'll be a problem in use. Now I'm on the lookout for a clapped-out 4-horse to build as a kicker.

 

[juno pierrat]

great reporting on the rebuild and pics to fallow along, almost a 100 posts and over 1000 views, could be a record!

 

[interalian]

Thanks, it's been fun. I had lots of help too, a shout-out to emdsapmgr oldboat1 flyingscott Faztbullet racerone jimmbo for their patient support and answers. I'm usually very confindent tackling any repair, but this one was more involved than anything I've done in a long time. Gratifying to complete and happy it lit on the first try (first crank was before priming, just to test the starter).

I'm sure there'll be a couple more questions during tuning, but I need to break it in. So far it's only been idling on 50:1 gas - lots of people around here suggest running 25:1 for break-in, even though the original handbook just says to run 50:1. So...

 

[interalian]

Part of the work required some 'special' tools, so I made them. (I'm cheap.)

Left: A piston stop tool made from an old spark plug. Cut off the top, knocked out the porcelain, tapped 5/16 UNF and threaded a bolt in. Set to 0.750" from the shoulder washer, worked perfect for aligning the timing pointer.

Center: A carb jet tool. A worn #1 Philips screwdriver had the correct OD for the jets. Cut the end off and filed flats straight and parallel until they just fit in the jets. No danger wrecking the jets.

Right: A piston pin clip installation tool. Notched a junk flat screwdriver. Screwed some scraps of wood to the bench to hold the piston so it wouldn't move.

 

[J140TLCIH]

Dam. I got a lot of work ahead of me. Thanks again interalian. I always wanted to do a complete build, but I've always hesitated. But after reading this, i have some notion of what is ahead.