Jump to content


Photo
- - - - -

Rev Counter


  • Please log in to reply
5 replies to this topic

#1 Kerrin

Kerrin

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,056 posts
  • Location: Isle of Man
  • Local Club: Manx Mini Register

Posted 13 March 2010 - 10:38 PM

Just got my mini 2 running for the first time in a while. the engine is an SPI but is fitted with an electronic coil and dizzy.

I fitted second hand Magnolia clocks during the rebuild, and the rev counter seems to be showing about 1,800 rpm but the tickover sounds like it is revving at the correct speed.

The old black faced Mayfair 90 mph clocks seemed to work correctly but that was the old MG metro engine and running points

Is it possible I have MPI clocks and they run double due to the twin sided coil?

If I cant get it working I can put the Tacho out of the old clocks into this one and change the faces over?

Cheers

Kerrin

#2 taffy1967

taffy1967

    Whovian

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 9,896 posts
  • Local Club: South Wales Minis

Posted 15 March 2010 - 12:29 AM

Isn't there an adjustment screw on the rear of the rev counter?

#3 Kerrin

Kerrin

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,056 posts
  • Location: Isle of Man
  • Local Club: Manx Mini Register

Posted 15 March 2010 - 09:07 PM

Do you mean on the back of the housing, or inside on the circuit board?

I will have a look at the spare set.

It is definately reading double, it would barely tick over at 1,400rpm

#4 L400RAS

L400RAS

    Up Into Fourth

  • Traders
  • PipPipPipPipPipPipPipPipPip
  • 2,479 posts
  • Local Club: Lincolnshire Mini Owners Club

Posted 15 March 2010 - 09:14 PM

Hi Kerrin,

Yes, the MPi rev counters will read double due to the "wasted spark" of the MPi. You can tune them in to run on a normal coil setup like the SPi, there is a potentiometer, which you can turn with a screwdriver to set it. You will have to have the car running , with the gauge partly disassmebled, and a timing light connected to get the true rpm reading. There is a thread on this forum on how to do it - with pictures, but the search button does not like me...

Ryan

#5 Kerrin

Kerrin

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,056 posts
  • Location: Isle of Man
  • Local Club: Manx Mini Register

Posted 15 March 2010 - 09:24 PM

Great, thanks for the info, the search likes me even less :)

I really didnt want to split my spare clocks apart unless I really have to.
Right I will try a search, just got to get Mrs Kerrin to bring tea at hourly intervals :P

#6 Kerrin

Kerrin

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 1,056 posts
  • Location: Isle of Man
  • Local Club: Manx Mini Register

Posted 15 March 2010 - 10:48 PM

Luckily I did find some old posts, but it is dubious as to whether the MPI gauges will turn down far enough on the adjustment as they do in fact run at half the signal from the double coil.

I think a gauge swap is the safest bet unless anyone else has managed to adjust this correctly?




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users