Distributor advance

**Sponsor**

by **kmam** » January 10th, 2018, 6:35 am

I can’t find any info on how the distributor advance works on the M151A2, which I assume is the same on all 151s. Can someone enlighten me or point me in the right direction please?

by **SturmTyger380** » January 10th, 2018, 7:35 am

All these type distributors use weights on springs underneath the points plate. If you remove the plate you should see two springs. If I remember correctly one spring has more tension than the other to hold the weight in until faster rotation happens.

by **rickf** » January 10th, 2018, 9:30 am

What Sturm says is correct. Two different springs and I have heard a lot of issues of broken springs. But also it is common for things to get pretty rusty and stuck in there.

by **kmam** » January 10th, 2018, 4:18 pm

Thanks guys. so it is the same as the one on my Series 2a land rover. The springs on that gave up and the issues with the engine were weird, it was some time and lots of heartache before we found the cause!

by **rickf** » January 10th, 2018, 5:16 pm

You can see the advance clearly with a timing light. Watch the line as it revs up and it will advance as the rpm goes up and as the rpm comes down it should drop down nice and smooth. If it is bouncing around or it advances very quickly at a moderately low rpm then one of the springs is broken. If it does not advance or if it hangs and then advances in a jerky fashion in both up and down then it is rusty. Really, anything other than a nice smooth transition up and down means you should look into it. Not hard at all, I scribe a line on the bottom of the distributor to mark the position for reinstalling it without having to go through the timing bit and then just pull it out and do it on the kitchen table. (When the wife is not home of coarse!)

by **kmam** » January 15th, 2018, 9:34 pm

Pulled it apart today. Everything looks good with the weights and springs so gave it a good clean, oiled/greased and reassembled. Have timing right anf it advances/returns as it should. Engine spins up beautifully.

I think my problem was a combination of timing, mixture, idle settings which was causing a little erratic behaviour.

One side effect: when the engineis at about 1500+ revs there has been a terrible loud vibration which I cannot track down and drives me nuts! Well that has now gone!! Don’t know why but I did have the antenna on todat and I wonder if the tension creatd by the tying down may have stopped some vibration in the antenna mount/body? Whatever, if it does not come back I will remain a happy chappy...

by **rickf** » January 16th, 2018, 9:56 am

These engines are not balanced so you will get some big time vibrations at certain rpms. 15-1700 is one of the areas and technically if you double that then it will vibrate there also. I personally do not run mine up to 3400 rpm. There are a couple of guys who had their engines balanced when they had machine work done to them. I think maybe Horst did that to his. I am curious to hear if his has the normal vibration. The other one I know about was sold from here in the US to a buyer in Sweden I believe.