A couple more Airhead Q's...

[Wrigsby1]

I have been tearing the R80RT down a bit...
The back end and gearbox is off and the clutch removed... The bell housing was dry and the clutch plate thickness was over 5mm... The clutch as a whole took a bit of releasing and seemed to have seized a bit on the pins so I suspect it was hanging slightly on these causing it to slip now and again... I am going to clean the clutch up and re-install as this is a pet maintenance project and is not going to be a big use thing or a money pit...

I was surprised at the clutch as it seemed to be the orig and was so lightly worn but will put it down to sensible use and lack of power Splines etc fine so no major probs... Does the diaphragm spring go weak or is it strong enough for reusing?

PIA bit... The gearbox changed fine when in use and had no major use issues but has a rough output bearing when out of the bike which I suspect to be the output end as it feels pretty immediate... I will have to take a closer look... Lots of great advice on the forum...

The oil also looked a bit emulsified which is a bummer as the seals seemed fine...

I think this bike, after a fair bit of use, is suffering from sitting around for too long which is usually a PIA for bikes in general...
Also the odd bit of brutal maintenance like the scratched chrome (now smoothed) on one fork causing a seal leak, and which is always annoying to see...

Are there any telltale signs for valves snapping or do people change them as a precaution? Exhaust valves seem to be mentioned mostly...

Good for keeping the winter nights occupied anyhow...

 

[SeanW]

Water usually gets into gearbox via perished boot where speedo drive enters gearbox...

 

[Wrigsby1]

Water usually gets into gearbox via perished boot where speedo drive enters gearbox...

Thanks, I had read about this and mine seemed OK but I guess they go a bit weak with age and the silicone trick seems to be the way to go... Also perhaps people with pressure washers are a bit overly sometimes as that would do the job nicely...

It's a shame that the oil probably didn't have a drain for a while and also the fact gearbox reliability seems so varied across manufacturers... A mate has the classic Renault/Vauxhall van problem where the gearbox lunches itself at 80kish, I have had the M94 gearbox rebuild on an 1100 at great expense but have a big LT35 van where the gearbox is seemingly maintenance free for life!