Timing the ignition on a 1976 250SL

[yannis45]

Project is almost over. in fact i did drive the beast a few times. I get some issues that I believe are related to the timing of the ignition so I need some advice.
I had to replace the coils because the old plate was gone. the replacement is from a Suzuki 250 wisely proposed from a forum member. with a new flywheel and a persistent application of a file the fit worked but I am pretty sure the timing is out of whack. the owners manual is not very helpful although it provides all the numbers it doesn't day anything about where to measure the angles. On top of that you have to have the engine running to test and then take the flywheel out to adjust and back again.

Any advise on how to accomplish the task? any tricks to it?


thanks

John

[Zyx]

I would suggest finding a Suzuki manual and see how much of the timing regimen follows what you need to do in the Hodaka.

You need to find a TDC reference mark on the backing plate and/or flywheel, and on the engine case. Otherwise you have no frame of reference. The Hodaka specs say 1.1mm BTDC (0.043"). Assuming you can identify TDC on the flywheel and backing, setting it to the BTDC setting should be easy enough and then, if needed, make your own mark on the side case and backing plate for future use.

I suppose you can also use a degree wheel for static setting if what you have for ignition reference is in degrees, but you still have to find TDC to set the wheel.

Or, since you have a running engine, you can assume the timing is at least in the ball park. With a timing light, you can identify when it is firing, but it will be advanced or retarded depending on rpm and preset curve. If you know how much the CDI runs advanced at idle, you can make a reference mark wherever that running point is now, then compare that to TDC. That should let you know whether to advance or retard the static setting, by moving the timing light reference toward where it needs to be, which you could do with a degree wheel.

Isn't there a visible TDC mark on the engine case?

[olddogs]

You dont mention the issue you think is timing related. This info may help us point you in the right direction. I have had a few 250s and spark knock was always the demon I chased.

[taber hodaka]

I use a nail down the spark plug hole.----------Clarence

[hodakamax]

I use a nail down the spark plug hole.----------Clarence

Clarence, would that be a metric nail?

Max

[racerclam]

Just so you know the stock 250 sl and ED cdi box actually advances at High RPM just what you don want a 2 stroke to do. So on my RG 250 i used a cuper combat CDI box since it retards on top . But then the stator plate needs to be slotted to advance initial timing or it will be retatded a bit.

Rich

[Zyx]

I have used screwdrivers, Allen wrenches, copper wire, and whatever was handy to find TDC. Point is if you don't know where it is, it is hard to set timing.

Anyone know the advance curve characteristics of the 250 Suzuki unit? That's what the OP is using.

[Dale]

This previous thread has more information regarding the Suzuki CDI box...
viewtopic.php?f=1&t=942&p=4718&hilit=suzuki#p4718