R60/6 '75 backfiring issues.

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Lasse
Posts: 30
Joined: Tue Aug 03, 2010 12:32 am

Re: R60/6 '75 backfiring issues.

Post by Lasse »

Got the pointsplate screws out, replaced with some undercut ones, not the correct type, but hey I will be able to get them out.

Since the F mark came on at 1000 RPM before I set the gap I thought I'd retard it abit, but that just gave me light backfires. So I set it back to where it was running fine. I want to dig furtherer into the timing of these machines, but for now I am just happy that she idles and responses well to the throttle :)
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Airbear
Posts: 2878
Joined: Tue Aug 03, 2010 10:02 am
Location: Oz, lower right hand side, in a bit, just over the lumpy part.

Re: R60/6 '75 backfiring issues.

Post by Airbear »

Sounds like you are on the right track, or at least in the zone. I recall you writing earlier that you had fiddled with the mixture screws. Maybe the 'light backfires' are from the mixture setting of one or both carbs. I would concentrate on getting the ignition timing spot-on first - F mark in the middle of the window at 3000rpm using the strobe - also confirm that your valve tappet clearances are correct - then you can start on the carbs with confidence.

Note that there can be disparities between the static timing you might have to do on the side of the road (S mark in the window at idle - usually sufficiently accurate) and the dynamic timing with the strobe, due to the state of your advance unit springs. It is best to get the dynamic timing correct, since your engine will be spending most of its running time at full advance.

Just in case you don't know about it, it is an important safety measure to disconnect the battery before you remove or install the front engine cover. A minor slip while removing the cover can result in a short to the diode board - an expensive matter you will wish to avoid.
Charlie
and Brunhilde - 1974 R90/6
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Graduate, Wallace and Gromit School of Engineering and Design (Pending)
Sunbeem
Posts: 1032
Joined: Tue Aug 03, 2010 4:42 am
Location: Bentham Lancaster England.

Re: R60/6 '75 backfiring issues.

Post by Sunbeem »

Hi Lasse,

Your seat looks like mine, and I've struggled myself. After much scratching of paint, I found the best way is to free the rear hinge first, then the front comes free with the seat slightly lifted, maybe 25 or 30 degrees.

The bike looks very clean, for something to suddenly go wrong seems odd - I'd be tempted to empty the tank and give it a wash out, so you know where you are with your new acquisition. If one of the little tubes has fallen out of a petcock, you could be getting occasional inclusions of water in the fuel. Unlikely perhaps, but you need to know what's going on, or rather ... "in."

Sunbeem.
One day more -- one day less.
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SteveD
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Joined: Tue Aug 03, 2010 3:29 am
Location: Melbourne, Oz.

Re: R60/6 '75 backfiring issues.

Post by SteveD »

Sunbeem, I think the earlier seats had the frame studs configured differently, so removal wasn't quite so simple as ours.
Cheers, Steve
Victoria, S.E.Oz.


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arbalest
Posts: 15
Joined: Mon Aug 09, 2010 9:07 am
Location: Windham, Maine

Re: R60/6 '75 backfiring issues.

Post by arbalest »

I had a R60 motor with R80 cylinders that gave me fits with timing wandering all over the place. Do yourself a favor and buy the Boyer kit for airheads. I replaced my points with the Boyer setup, and that was the end of the problem. No points to set, no more worries. Just drive it. Airheads are wonderful motors. Enjoy.

Mike Lydon
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Lasse
Posts: 30
Joined: Tue Aug 03, 2010 12:32 am

Re: R60/6 '75 backfiring issues.

Post by Lasse »

Wondering the same thing, however the Omega seems to also be a sweet deal.
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