Loud "clicking" at higher RPMs

[kevin d]

My first two thoughts were :

- Sticking valve
- Distributor advance weights

Thanks Ed, would MMO help with the sticking valve if that is the case? Also, I'm not very familiar with the distributor advance weights. What should I be looking for? Or how would I isolate the issue to them?

[kevin d]

Quick questions...

Can someone describe the easiest way to set the ignition timing?

And what is the best way to check if the mechanical fuel pump is working properly?

Thanks

[edwardc]

Yes, some MMO in the oil (up to one quart!) and some MMO squirted into each cylinder after each use (or as often as possible) so it can soak between uses is the usual course of treatment for a stuck/sticky valve.

The advance weights and the springs that control them are located in the distributor, underneath the breaker plate. If they get stuck out, that would result in excessive advance which could cause "pinging" and poor running.
Easiest way to evaluate them is to just open the distributor and remove the breaker plate and examine them for smooth operation and no broken springs.

[Marian Claire]

This may answer your timing question. http://www.moyermarine.com/forums/sh...ghlight=timing Dan S/V Marian Claire

[kevin d]

Thanks Dan and Ed!

[hanleyclifford]

Hanley, there are so many pressure gauges listed in the McMaster link, could you be more specific and tell me which one you used? Also, is this gauge plumbed into the fuel line with a tee as would be for a gas pressure gauge? Or in line, like a flow meter gauge? Did you mount your gauge on the output of the fuel pump, or on the input to the carb or in the middle of the fuel line (rubber or copper line)?

Thanks, Herb

Right at the "G" spot:

[seabreeone]

Clicking

I had an issue like this last year. I tried everything. It turned out to be #4 valve would stick at high RPM'S, At low R's it would free up. I had just the right amount of carbon and varnish on the stem to hang it up.I had to remove the head reem the guide and then I put in the after market valve springs. They are taller and stiffer.Runs well now

[Sony2000]

I fully agree with seabreeone, but if the power loss is greater than just running on three cylinders, then I would look for fuel starvation.

[hanleyclifford]

Whenever a problem like this develops the first thing I do is check the basics: timing, both initial and centrifugal, dwell (even with EI), compression (though such test may not detect weak valve spring), cleanliness and viscosity of oil and engine running temp (both of which can influence valve guides) and valve lifter clearances. Before going too far afield make sure the above are on spec. Because I believe in continuous diagnosis I have added fuel pressure gauge and air/fuel ratio gauges. If things are not allowed to go off spec problems are rare.

[kevin d]

I think the first thing I'm going to do is rule out 'electrical' issues.

I'm planning to check timing, coil, spark plugs/wires, quick inspection of DC wiring, etc.

I may do an oil change, recheck the idle mixture and will inspect the fuel lines and gas tank vent.

Thanks for all your help....any other quick (do first) suggestions would be much appreciated.

Cheers!