Repaired Rev Counter fails after 15 months and 150 miles

[DJW]

Previous owner had rev counter repaired by JDO Instruments in March 2021 for sum of £100. This was to repair needle bouncing around.

150 miles later in June 2022 the same problem has re occurred. There was only a 12 month guarantee with repair.

I have contacted the company and they have stated £59 to repair if same problem, otherwise full price if something else, the latter being fair if this occurs

Just concerned I spend this money to find it fails again in 15 months time . What’s others experiences with rev counter repairs ?

[mark030358]

Hi Dave,
Usually a bouncing tach is evident if an electronic ignition fitted, as the tacho is originally an RVI type. I still has a little bounce after my conversion, but used a shielded cable for the tacho signal. You may have interference.

You can buy off eBay a square wave generator for a few quid and test the tacho without the engine running.

Cheers
Mark

[sprintsoft]

Hi Mark,

I’d be interested to test mine also can you give us an eBay link ?

Cheers
Iain

[DJW]

Hi Mark, thanks for info and also would appreciate link to right item as knowing me I would buy the wrong thing

[mark030358]

Here you go…

https://www.ebay.co.uk/itm/203966572841 ... SwFlhijcY8

Cheers

[sprintsoft]

Thanks Mark,

that's a useful bit of kit, have just ordered one...

I have a Spidya conversion on my tach which looks to have gone out of calibration and so this will help find where the issue is!

Iain

[DJW]

Here you go…

https://www.ebay.co.uk/itm/203966572841 ... SwFlhijcY8

Cheers

Now where’s that like button

[mark030358]

Let me know how you get on chaps please

Cheers

[DJW]

Just waiting for it to be delivered now

[DJW]

So dawned on me when I purchased this car Bruce kindly offered the option to switch it to electronic ignition or keep as points. I chose the former, which could explain the change in rev counter bouncing aligning with Marks original comments.

Ran it past JDO who confirmed yes that would be the cause and needs an upgrade at £157 . Doh

Hmmm return to points or spend the dosh. Suppose it’s worth reverting to just to confirm rev counter is working OK , then decide route.

Just a side note to say JDO have been excellent in correspondence to date.

[billwill]

I use a variant of electronic ignition, which is basically just a transistor amplifier, to produce a better waveform and hence a better spark. It still uses the points but ensures that the electric current is as low as practical, reducing sparking so the points last 'forever'.

These were originally Vellerman kits sold by Maplins (which is no more ) but are still available from various sources on the Internet.

I fitted heavier duty resistors and a heatsink, but I think they may have up-rated those components in the kit nowadays.

[sprintsoft]

Speedy Cables can do the conversion and fix any issues for you, all in one...

highly recommended, but normally there is a wait time...

https://www.speedycables.com/instruments/gauge-repairs-conversions/

[Quart Meg Miles]

Hmmm return to points or spend the dosh. Suppose it’s worth reverting to just to confirm rev counter is working OK , then decide route.

You're not going to wear the points out with low mileage; keep it simple like it was still 1970.

[DJW]

Speedy Cables can do the conversion and fix any issues for you, all in one...

highly recommended, but normally there is a wait time...

https://www.speedycables.com/instruments/gauge-repairs-conversions/

Yep , just got quote which is similar to JDO, but 8-10 weeks turnaround from receipt of dial. Obviously a victim of their own success

JDO are only a couple of days , so will probably go that route when temps drop. Garage is like a sauna !

[alan.barker]

Just fit "hall effect" from simonbloc and bin the electronic system.
Alan