From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Spark Arrestor - Onan 4K
Date: Wed, 13 Sep 2000 14:21:40 -0400

onourway wrote:

> Anyone know a secret to removing the 2 bolts under the muffler that
> regular maintenance requires on my Onan Microlite 4K. Mine are rusted
> shut.

A product called Rust Buster.  This foul smelling non-oily liquid is
the most amazing stuff I've ever seen, heads and shoulders above
penetrating oil and other solvents for rusted bolts.  It was
developed for the HVAC industry and excels at freeing rusted fans
from motor shafts.  After application and an hour or two to sit, the
rust just sorta crumbles off.

I get mine at Johnstone Supply, an HVAC supplier, though Graingers
and most other industrial suppliers have it.  Johnstone's part
number is G84-621.

After soaking the bolts, you need to use a tool called an impact
wrench.  Not an air driven too, this a handheld tool that when
applied to a bolt or screw and struck with a hammer, applies a sharp
torque to the fastener while simultaneously subjecting it to a shock
wave.  The combination will break almost anything loose.  My wrench
is by K-D.  It has a 3/8" square socket drive nose and comes in a
kit with an adapter and a variety of screwhead bits.  Cost is about
$35 as I recall.  There are some cheap chinese knockoffs out there
which don't work nearly as well so get the K-D if you can.

If the bolts won't ease loose with the Rust Buster and the impact
wrench, try heating the assembly, conveniently by running the
generator :-) and try again.  Worse comes to worse, you can twist
off the bolt heads, drill the body of the bolt out and install
Heli-coil thread inserts.  When you put the bolts back in, use some
high temperature nickel-based anti-seize compound on the threads.

>What's the downside to doing nothing.

The arrestor will eventually stop up and the engine will stop.

John