Topic: Timing 350F

[sfhurst]

I have just completed a complete rebuild of my '73 350F.  I performed a static timing prior to my first start.  The bike started and ran pretty well, but when I attempted to set the timing with a timing light while running I found there was insufficient movement of the points backing plate.  When rotated clockwise as far as the mounting screw slots would allow, I am still off by 2-3 degrees for cylinders 1 and 4.  What's wrong??

[newday777]

What points gap did you set to? Try adjusting it a little wider.

[Flyin900]

Are they OEM Honda points or aftermarket pieces?

[sfhurst]

eBay.  Can't remember if actual Honda or after market.  I will try opening the gap a bit.  Thanks.

[bryanj]

Remember, when you turn the plate the ga will alter and when you alter the gap the timing alters, it takes a lot of juggling, cursing and adjusting to get both gap and timing correct untill you have done it multiple times. And even then it can be a pig!

[sfhurst]

I have rechecked the point gap and that helped.  When I do a static timing check the light comes on exactly where it should for both 1-4 and 2-3.  However, when I use a timing light with the engine running the mark is off so far there is not enough travel on the plate to align the marks.  They are both off by the same amount.  I believe that if I could get 1-4 correct, 2-3 would also be correct.

[RAFster122s]

Could be Crappy Chinese Parts, CCP at its finest! And you thought it stood for Chinese Communist Party!
Daichi points are known for terrible build quality and points that cannot be adjusted correctly as their geometry is wrong. Their condensers tend to be bad out of the box or fail almost immediately. The market is flooded with them. They have three pointed leaves like a propellor.

[BenelliSEI]

And don’t forget the plate itself. A buddy of mine bought a “new” plate, points and condenser complete, on EBay. When compared to an old HONDA plate the slots were just plain off, by about 1/2 the slot length!

[HondaMan]

Something to be aware of:
The points advancer springs on your 350F have become very soft from the years of heat-annealing, and they now let the weights advance far, far sooner than they should. What you 'see' from this is: after setting them statically and then looking at them with a timing light, they show advanced timing at idle. This is because the springs have become too soft: attempting to then adjust the idle timing to the marks ends up with the full-advance timing not happening right, either - it doesn't reach far enough.

Sound familiar?

To fix this, remove the slack from the springs where they connect onto the posts of the advancers, after cutting off at least 1/2 turn from no less than 1 of them, and you'll likely find (before this is set right) that you need to remove 1/2 turn from both springs. They MUST pull the points cam to idle with some panache' so that it does not start to advance until the engine is passing 1250 RPM, and the idle should be 1000-1100 RPM with no advance at all.

[sfhurst]

Exactly what my next step was!!  Thanks for confirming.  Like the chicken and the egg.  Is the higher RPM advancing the timing, or is the higher RPM due to the advanced timing?  Off to check the springs.  Thanks.

[HondaMan]

The timing starts advancing at idle speeds when the springs get soft and sacked. I've seen the 500/550 and 350F engines showing 50% of the advance already in at 1100 RPM, WAY too soon. This makes for very poor running, darkened sparkplugs and impossible idle speed control, not to mention it falls flat on its face until 4000+ RPM because it is spitting back up the intake tract from the overlap cycle touching off the fuel in the intake pipes. Full advance must no happen until at LEAST 2200 RPM, and with today;s fuels 2500-3000 RPM works better.