G5 Engine Overhaul

michael_s · Post by **michael_s** » Mon Oct 31, 2011 7:49 pm

quote:
because to change the plugs back they would have had to remove the engine again from the frame.

sure? I have access to both plugs...

ajscomboman · Post by **ajscomboman** » Mon Oct 31, 2011 7:59 pm

You have accesss to both plugs but if a previous owners has mistakenly swapped them around you'll find that the larger plug won't pass through the access hole in the bottom cradle.

michael_s · Post by **michael_s** » Mon Oct 31, 2011 9:05 pm

Ah I didn't know that

I still wonder what makes the bearing cage fail...

I had a closer look at barrel, piston and rings today, ring gap is 0,015, piston clearance app. 0,07. I think I'll go fpr having the piston coated as recommended by a fellow austrian member.
Edited by - michael_s on 31 Oct 2011 9:15:54 PM

BigAl350 · Post by **BigAl350** » Tue Nov 01, 2011 8:14 pm

Coated...with what? As an owner of a Model 8 350 Lightweight with bad piston slap, I'm FASCINATED as to what this means?!!!

Al

quote:
Ah I didn't know that

I still wonder what makes the bearing cage fail...

I had a closer look at barrel, piston and rings today, ring gap is 0,015, piston clearance app. 0,07. I think I'll go fpr having the piston coated as recommended by a fellow austrian member.
Edited by - michael_s on 31 Oct 2011 9:15:54 PM

cbranni · Post by **cbranni** » Tue Nov 01, 2011 9:11 pm

I am also fascinated

bigwol · Post by **bigwol** » Tue Nov 01, 2011 11:14 pm

me too

michael_s · Post by **michael_s** » Wed Nov 02, 2011 9:34 am

http://www.baier-motor-racing.de/kolben.html
or http://www.pistoncoating.de

(sorry, german only)

Helmut (the guy who recommended it) had his G3 piston coated plus barrel rebored/honed at Mr. Baier's. Meanwhile, the bike has done 12.000kms, no seizing (10/100mm piston clearance!), coating still in place.

Sounds too good to be true?
I´ll give it a try, quote is 65 Euro.

Stil looking for new rings, though...Edited by - michael_s on 02 Nov 2011 09:36:02 AM

BigAl350 · Post by **BigAl350** » Wed Nov 02, 2011 1:21 pm

The pistoncoating.de website says this about the coating:

"The technology of this coating has its origins in the storage technology of aviation and spaceflight. As a former technical director of an aircraft bearing manufacturer and dedicated racers I transferred my knowledge to the engine technology of motor vehicles. A series of tests have confirmed the soundness, and long-term tests the durability of the coating. Because of these successes I decided to offer the coating as a way of optimizing or repairing pistons. the positive customer feedback encouraged me to develop to other uses (camshaft bearings, connecting rod bearings upper) and deliver in the future. "[quote]

It uses a Molybdenum Disulphide coating (MoS2). There's something here about the use of piston coatings too: http://profeng.com/tech/piston-coating

I think we'll all be very interested to see the results of you using the coating on an old piston, rtaher than its use on new pistons. Please let us know you findings! I am rather sceptical though...

Al

michael_s · Post by **michael_s** » Mon Nov 14, 2011 1:29 pm

Sorry, coating called off...
I took the barrel and piston to a local borer, clearance is "only" 0,12mm.
(initial measuring was done by a friend working for a laser measuring company, apparently not specialized in motorcycle engineering

Barrel was only lightly honed and I decided to just fit new rings (which are on their way from messrs. cox & turner) and leave it at that....