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Distributor mechanical advance query

Posted: Sat Mar 16, 2024 1:32 pm
by Mr Spigot
Trying to track down the lack of power in my 1952 MM (918 engine) going uphill (down to 15mph), I have been focusing on the distributor as the car starts and runs fine, ticks over beautifully and will run up to 55mph on the flat, but as soon as it hits a hill, the power drains away. I have checked timing, points and fitted and gapped new plugs. Having taken the points baseplate off to look at the advance weights, I noticed that there seems to be no tension in the springs and the weights will move and stay in position with a 3-4mm gap without closing back together - see photos. Do I need a new set of springs? If so, where from? The distributor is the DKYH4A 40251.

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 2:45 pm
by les
I’d start by removing the assembly and giving the parts a good clean, to eliminate any possible sticking.

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 2:54 pm
by Mr Spigot
The weights move quite freely with no sign of sticking.

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 2:56 pm
by svenedin
If you send your distributor to a specialist it can be rebuilt. It will be put on a machine to check the advance curve. This is expensive though.

Stephen

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 3:13 pm
by Mr Spigot
Yes, I have done that with my other Minor. I am looking for the easy and cheap fixes first and working up from there. New springs ( if the problem) are a lot cheaper than a rebuild at Distributor Doctor.

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 4:55 pm
by philthehill
First thing I would do is check the compression.

Re: Distributor mechanical advance query

Posted: Sat Mar 16, 2024 6:10 pm
by Mr Spigot
Compression test showed the following:
1; 112 psi
2: 118 psi
3: 120 psi
4: 117 psi