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RE: Whats wrong with this TRactor motor?

To: <triumphs@autox.team.net>
Subject: RE: Whats wrong with this TRactor motor?
From: "Randall" <tr3driver@comcast.net>
Date: Mon, 6 Mar 2006 11:56:39 -0800
> There are a couple verticle
> scores in one cylinder that might be a good thousands or two
> deep.

To me, that would decide it.  Unless you're absolutely broke, don't bother
putting it back together with a scored cylinder wall.  At the very least,
pull that piston to see what caused the scoring.  If you're nearly broke and
the piston isn't badly damaged, you can probably hone out the scoring and
just replace the rings to "get by".

The spread in compression values says something is not sealing well, the
smoke from the crankcase is a pretty good indicator it's rings.  With the
engine that far apart, I'd want to have a look at them.

Hmm, guess I'm assuming you've changed the oil and there was no water in it
?  If the headgasket was leaking water into the crankcase, that might be the
source of the steam, but you'd see the water when you changed the oil.

> Without being a machinest or engine guy is there a good way to
> tell if there
> is too much clearence around the pistons (without removing them)?

Not really, but piston/cylinder clearance is not all that important as long
as there is enough.  The rings are what seal the combustion gases ... excess
piston clearance just leads to piston slap, a relatively minor annoyance.

> One more thing. The marking on the second piston from the front
> is numbered
> #1 and the front is #2.

So, combined with the lack of torque on the head studs, a very sloppy
reassembly by someone.  The correct order is 1,2,3,4 from front to back.  Be
sure to look for other things they might have done wrong, like leave out the
circlips to retain the wrist pins.  I'd retorque the bearing caps, too.  Be
sure to check the threads on the head studs, by spinning a new nut down
them.  If they are stretched, a fairly common occurrence, the nut will bind
partway down the threads.

> I have the plug wires so that the top left wire
> in the dizzy
> goes to the front cyl. The top right goes to the second back. The bottom
> left goes to the third back and the bottom right goes to the
> rearmost cyl.

Sounds right to me.  The dizzy turns CCW as you look down on it, and the
firing order is 1-3-4-2.

> I timed the ignition so that when the front cyl was at TDC The points just
> opened to the top left dizzy wire then gave it approx 4deg. more. Is this
> right?

That's the factory initial setting.  They recommend to "fine tune" it on the
road, but that is close enough that the engine should run fine.  Definitely
not the problem.

Randall


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