Terryc wrote:
The old Victa lawmmover (B&S engine) is about 20 years old. It sill
starts okay, but needs to run for 10-15 minutes before I can open the
throttle[1].

Worth repairing or should I just replace it?


If i replace it, is it hard to self-repair? I'm thinking it might be new
rings to seal worn cylinder, etc and am wondering how difficult that is
to do for a single cylinder engine? Probably use it as a home made
generator/battery charger.


[1] Not a problem if I just want to take the top off at the higheast
setting.


Hi there Terry, and everyone else as this is my first post to aus.gardens.

Does it run on after you to stop it?
I guess it may be hard to tell if you use the throttle to do so. But it
could be in need of a de-coke. You just pull the head off and scrape
out all the carbon from the top of the piston and inside of the head.

Then there is of course the old "bush mechanic's de-coke".
Where you get the motor running and warmed up with the air-cleaner off,
and very gingerly squirt water into the air intake.

This has the effect of steam-cleaning the top of the piston and the
inside of the head. If you do this however, be very careful to only
squirt in a little at a time, not too much at once, as water is not
something you can compress. I will leave you to imagine the
consequences (something has go to give). So do so at your own risk.

I must say though, that I have done this myself with good results on a
few different motors, 2 and 4 stroke. I used to have this old
side-valve 4-stroke generator that coked up all the time, but in the end
I got sick of pulling the head off to de-coke it, so used this method
for years to no ill effect. I did use an atomiser however. I know, I
know, I should have changed the oil rings, but I didn't want to crack
the base gasket as this involved splitting the crank-case, which
involved removing the exciter and on and on.

A bloke I know here in Queensland said he sells re-built B&S motors for
about $450.

One of my brothers swears by his old 2-stroke victors.
He has changed the ring (singular) :-) himself, but mostly he just
threatens them with being taken to the tip. :-)
Although the problem is that (as with any motor) a lip develops over
time in the un-swept portion of the top of the bore, which needs to be
honed out if you want to put the next over-size (or even the same size)
ring in. Otherwise, if it's at all a large lip, it may well crack the
new ring.

You can get lip removing tools, but they are not cheep.
The bore will also need a light hone.

HTH.
-Adrian