[see_ex_500]

Greetings all.

Bike: 1981 cx500 shadow (oz)
Murray’s Mikunis
Ignitech

Problem: bike is white whale..as in; I can get it running amazing MOST of the time. After a good long ride, the right cylinder starts to splutter under VERY low throttle. Idles fine, runs fine once we get onto the main jet (primary jets are clean BTW).
my only thoughts are vapour lock? Or something fuel related? It only really happens after 30-45 minutes of good riding.
My fuel requirements are minimal at that throttle setting, so I’m ruling out “fall” in the fuel line. Coils heating up? They’re after market coils from DR 400 (or something like that).

Thanks in advance for your help team!

 

[CXPHREAK]

I would be testing the low speed pickup for the right side both hot and cold.

 

[see_ex_500]

I would be testing the low speed pickup for the right side both hot and cold.

Are these still needed even with Ignitech? I know I have a problem with those pickups, that's why I replaced them with Ignitech.

 

[CXPHREAK]

The ignitech still uses the stock left and right low and high speed pickups.

The ignitech replaces the stator CDI power function and the advance coils but still uses the stock pickups unless you are running a raesan hall conversion with the ignitech.

 

[see_ex_500]

The ignitech still uses the stock left and right low and high speed pickups.

The ignitech replaces the stator CDI power function and the advance coils but still uses the stock pickups unless you are running a raesan hall conversion with the ignitech.

Can I replace the stator without taking the motor out?

 

[reclinedrelic]

No. The same goes for the pickups. Both are engine out procedures.

You can test them by measuring their resistance, cold and hot, to determine if they are the cause of your problem.

 

[CXPHREAK]

It's not the stator but may be the pickups. The short answer is still no as they are inside the rear cover above the stator.

These are the pickups with the red circles.

1,2,4 and 6 here. You would need to test the resistance cold and then hot after a ride to see if it goes out of spec when hot.

 

[see_ex_500]

Is it common for this problem to only rear its head when the bike gets super warm?

 

[CXPHREAK]

It can be. Resistance naturally increases with heat. If it is high to begin with it will climb higher when warm. Sometimes a coil in the winding may be broken and heat expansion can cause loss of contact in the wires or cause the coil to short back on itself if the insulation is failing reducing resistance. There is no one size fits all failure mode.

 

[see_ex_500]

I see. So looking at a solution without engine removal... Do you know if there's a Rae-San product I can fit to work in conjunction with the Ignitech and solve the problem?

 

[CXPHREAK]

Test it first.

But raesan make a hall module that works with the ignitech that can be fitted without dropping the motor or removing the rear cover. It fits where the CDI advance unit fits and is accessable through the small steel cover on the back of the main rear engine cover.

 

[see_ex_500]

THAT sounds like the solution for me! I’ve hit Ray up just to be sure. As I mentioned…the 5/9 reading from the stator was cactus when I checked last year, I’m sure that’s the issue (changed every other bloody thing on the bike).

 

[CXPHREAK]

The ignitech doesn't use the 5/9 so that's not an issue. Only 1/5, 2/5, 3/5 and 6/5 are an issue here, especially the 1/5 in your specific circumstance.

 

[see_ex_500]

Mmmmmm. Interesting. What else could make it miss when it gets hot.
I did have the heads off last week; new stem seals as it was smoking up a bit. Everything went back together nicely and has been torque-checked and clearances done 3 times.

when I got back from the long ride today, the offending plug was oil fouled. Maybe the rings on the side are just fucked?

 

[CXPHREAK]

Try swapping the spark plugs across the motor to see if the issue follows - though I doubt it will be the plug but in the process of elimination it should be ruled out.

Follow that with the plug caps which are a possibility here.

Then swap the ignition coils and see if the issue swaps sides.

If you've had the heads off check your valve clearances {and do so after each retorque} Too tight a gap can cause compression loss and compression loss has its largest effect at low RPM when the compression has more time to escape. At higher RPM there is less time for the compression to escape. Differential expansion rates may be a factor with this issue becoming worse when hot.

 

[Hermannsson]

Some things to consider: Carbs synchronised ? Both idle pilot screws can be adjusted ?
If one plug is black it may be faulty carb sync or valve clearance. Both can be checked and corrected easily.
Before you consider spending money on ignitec you should check the blue and white cables at the CDI, there should be approx, 80V ~ when engine is running - and hot. If that's the case your generator works well.
But this may not be the case when the generator is quite old since it's bathed in hot oil all the time.
Check cables from CDI to ignition coils, check whether the plug cable are screwed in correctly, both sides: plug cap and ignition coil.
Good luck with your CX