Topic: Ignition Timing Problems

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I'm setting the ignition timing on my '74 CB750 for the first time today and am a little confused.

I've been referencing the shop manual and hondachopper.com to do this and it seems pretty straight forward, but things got out of whack when I set the gaps for the points.

Before I set the gaps I used an inductive light to see where I was at and it looked like the timing was a little retarded (it was lining up with the T instead of the F). After that I decided to set the gaps for the points and found out that they were a little too close, so I gapped them to the proper .014" when they were open the most.

When I start it now the ignition timing is too advanced (lining up between the F and the 1-4 marks) and I cannot rotate the plate anymore to retard the timing.

What am I doing wrong? Thanks!

[seanbarney41]

Many points plates are made slightly too small, causing timing problems.  If you loosen the timing plate screws and the whole plate can shift around in the case so that it is off center, timing gets kinda tricky.  If this is the case, you have to mess around with not only rotating the plate, but shifting it sideways/up and down as well.  Some folks will make shims or use some extra feeler gauges to help keep it in one place while they time it.

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That makes sense! When I first adjusted the plate the timing would advance when I screwed the plate back in...

I notice a lot of guys change these plates out. Any recommendations on what to buy/how to swap?


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[seanbarney41]

Try and get TEC brand, which is the oem...you can get it from a Honda dealer, also can be found on ebay for cheaper sometimes.  Basically, anywhere else you will get Daiichi brand, which is the poor quality replacement that is probably causing your problems.

[Dr. Noisewater]

Could also just be your points. I had the same issue with my 550 after I bought new points, they were Daiichi. I made shims and tried everything I could. I eventually shelled out some money for factory points and all was well. Not sure if the 750 is timed the same way though.

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Thanks for the replies!

I ended up getting a Dyna S ignition. We'll see how that works out after I install it this weekend.

[calj737]

Icon - pay special attention to the Dyna instructions about maybe needing to adjust the black magnets on the plate to achieve your preferred timing settings. I also have this unit and am quite happy with it, but did have to make a small adjustment from stock settings.