7 replies to this topic

[MrVee]

I have a Morris Minor with a 1275 Midget engine and I need a diagnosis that I haven't been able to get on the Morris Minor forum. Lots of helpful advice but no clear diagnosis. I noticed that A C Dodd posts here, so I thought I'd take a punt, if that's acceptable.

I have a Morris with a 1275 Midget engine, an MG Metro inlet manifold, an HIF 44 carb and an lcb exhaust manifold. The cam appears to have 1M73 stamped on the nose.The head is a 12g940 and is not converted to unleaded fuel. The distributor is a Power spark electronic job.

The engine has always had an unreliable tickover, but recently it has also started to to hesitate and stutter at low revs, necessitating a bit of revving and clutch slipping to make smooth progress. I've replaced the worn float valve and seat but have done nothing else, including checking the needle. Neither have I checked lead or coil resistance etc. or the timing, not possessing a timing light.

I'd like to know what to do to get the engine running half decently so I can drive it to get it diagnosed, preferably by Mr. Dodd. I'd also like to know how to contact him to arrange a diagnosis.

I hope you will not be offended by this interloper!

Thanks.

[timmy850]

There are few things that you can check and change prior to a service:

What spark plugs do you have?
What’s the gap on the spark plugs?
What’s the coil you have fitted and what is the resistance across the + and - terminals?
What power spark distributor did you buy?
If you haven’t or can’t check the lead resistance, then a new set of decent leads should be fine
The rotor and cap also need to be free of oxidation
Check the tappet clearances are all OK and in spec
Have you checked the SU damper/dashpot oil is topped up? And what oil have you need using?
What needle and spring are fitted to the carb? Is there any degradation on the needle?
Have you checked for vacuum leaks on the inlet manifold?

Setting the timing is critical to decent engine performance and will prevent any significant damage from too much or too little timing. I would highly recommend getting a decent timing light and checking the idle timing, and seeing what the maximum timing is at 5000rpm

[68+86auto]

Until you can test and eliminate the ignition system as a problem, don't touch the carb. A timing light is NOT optional, buy one unless you are going to pay someone to do everything.

Edited by 68+86auto, 10 December 2024 - 02:10 AM.

[gazza82]

Try a Midget forum ??

How old is the fuel? ⛽️ ethanol goes off and also attracts water.

[MrVee]

Thank you all for your replies.

[ACDodd]

Contact me by Facebook messenger.

Ac

[ACDodd]

Contact me by Facebook messenger.

Ac

[ACDodd]

Contact me by Facebook messenger. You won’t get a clear diagnosis without someone looking at it.

Check out this video series for how to go through your engine,

https://youtu.be/Y6N...y-8n-KbFDAyAv_a

Watch all 4 parts.

Ac