Engine keeps going tach gets up to about 6700 rpm then falls backwards. If I keep reving it will suddenly jump back up to 8000+ rpm.
Any ideas  on what is happening?
Thanks
Alan

It could be as simple as the multi-pin connector at the back of the gauges needing a thorough cleaning. They're fairly fine gauge pins and corrosion gets in and doesn't let go, causing all manner of strangeness. Are there any other difficult-to-explain electrical issues? We use two-part DeOxiT (who really knows how to spell that bloody name?) and the product should be used on all of the connectors on the bike.

http://www.caig.com/

(it's actually DeoxIT)

intermittent connection on the power in the instruments specifically the tacho ?

some of the really early models have a slightly different issue of lagging revs indication ...or overshoot

whilst in there you could probably change some of the dried out electrolytic capacitors ...now nearly 25 + years old

 
just a thought

I see there are four different series of DEoxIT. Which is appropriate? Thanks,
Alan

I use the red and gold liquid in little nailpolish bottles with a brush.

Others use the spray cans also 2 parts, cleaner and treatment.

I don't know of the other 2 types, maybe different size containers?

The liquid one goes a long way, should see me and the K out! especially since I have two

sets, don't ask!

There is a few different brands of Deoxit, but just beware  it is a phosphoric acid based product . So don't get it on painted surfaces, and after about 10 minutes neutralize with metho.

smithy

Hi All,
Just to clear up a misconception in the previous post by Smithy there is only one brand of DeoxIT, it is made by Caig in the US and it available in several formulations, it is not phosphoric acid based and it does not need to be washed off nor neutralised. It is put on with either the small bottle with the little nail polish brush or an aerosol spray and after that it is coated with the DeoxIT Shield to improve the long term resistance to moisture. It is great stuff and works like a charm, it is much used by Hi Fi fanatics and electronic organ restorers plus it is very effective on PC's with contact problems like on the memory connections.
Regards,
K-BIKE

K-BIKE wrote:Hi All,
Just to clear up a misconception in the previous post by Smithy there is only one brand of DeoxIT, it is made by Caig in the US and it available in several formulations, it is not phosphoric acid based and it does not need to be washed off nor neutralised. It is put on with either the small bottle with the little nail polish brush or an aerosol spray and after that it is coated with the DeoxIT Shield to improve the long term resistance to moisture. It is great stuff and works like a charm, it is much used by Hi Fi fanatics and electronic organ restorers plus it is very effective on PC's with contact problems like on the memory connections.
Regards,
K-BIKE

Sorry if I have misled anyone , but I have used many brands of Deoxit . It is a metal conditioner and will remove corrosion or oxidation  , and will need to be neutralized with metho. I haven't used the Deoxit your talking about , but it does sound good. There are many forms of Deoxit branded phosphoric acid based products on the market from 500ml to 20ltr containers.

 Smithy  


                                        

Hi Smithy,
Thanks for showing us the can it is DE.OX.IT rather than DeoxIT all one word with no dots. The DeoxIT site is http://www.caig.com/ it really is great stuff for electrical contacts DeoxIT D5 and DeoxIT S5 are the two most commonly used. 
Regards,
K-BIKE