Dyna 2000 on a '79 cb650!!!

[soos]

Being bold, daring and stupid....


I bought a dyna2000 made for the cb- 750/900/1100 DOHC bikes...

I did eventually get it to work, and before you start thinking... COOL, i'm gonna get one, and slap[ it on...

Know this, without a REALLY good buddy that is a competent machinist, or being a machinist yourself
- DO NOT ATTEMPT THIS! -

That being said, I am a competent machinist, and dared destroying about 450 worth of parts for this...

The first problem, Dyna does NOT make a trigger plate that is the correct timing, or diameter as the cb650's.
the DOHC plate was measured about 3 or 4 times, after removing all parts, and the coresponding bolt patters was drilled onto a old cb650 timing plate.

Next the crankshaft trigger locating pin that came with the Dyna2000 kit was on the wrong bolt circle as compared to the cb650's locating pin on the stock advancer unit.
Fixing that took making a stepped pin, and drilling the center of the new pin on the correct bolt circle.
The stepped pin was to eliminate the stock pin hole and still re-locate the pin on the correct bolt circle.

After that I had to check the true TDC of the bike VS where the dyna ignition was showing.
Figures it was a ways off.
I had to slot he timing plate advanced... about 5/8 inch.
I then marked by eye the best i could, and re-marked the dyna crankshaft trigger for TDC.
I then removed it, took it in a indexing tool at work, and re-marked the 30/32.5/35/37.5/40 degree timing marks.
The crankshaft sensor also needed a tube like washer to tighten it properly.
It is a custom made by me as well.

After that using the new marks, and advancing as per the dyna instructions... WHALAA!.
RUNS GREAT!

Having just recently bored this motor out to 61mm, I have set the rev-limiter to 7000rpm and set a conservative timing advance(i think).
That is until I have worn her in properly...

The pics are of the bike just before checking the TDC after mods to timing plate and crank sensor.
There are pics of the timing plate before modification, as well as the crank trigger showing the step pin installed.

Oh, I cut off the rubber bit on the wiring loom from the trigger plate used to seal the wires where they come out of the engine case.
I slid on a stock cb650 trigger plate wire cover, and rubber grommet to seal in the stock hole for the wires.

Other than that, not too much.

And to think Dynatek recommended I not do this,they said it will not work.
I love a challenge sometimes!

l8r

[Volker_P]

Sometimes a man's got to do what a man's got to do?
Very excellent job. Congratulations!
I suppose it worked sometimes somewhat less straightforward like described in your nice article?
BTW, where are these carbs from?

[soos]

I suppose it worked sometimes somewhat less straightforward like described in your nice article?
BTW, where are these carbs from?

Yes, i did make a bit easier than it was.... A LOT of measuring, drawing, remeasuring, double and tripple checking as well as a lot of "i hope this works"


The carbs are off of a 1973 cb750.

Not that the originals are bad, I just hated the choke setup on the stockers.
With these the choke lever is on the side of the carbs. no cable to hang up if old/crusty, no little un-obtanium black choke lever to deal with if/when it breaks...
That and they are 28mm, unlike the stock 26mm's.
I saw no loss going to the 750 carbs, and have not wanted to go back since.


l8r