550 Igniter interchange success!!!!!!!!

[salty_monk]

Has anyone investigated the Megajolt? It's got to be very similar to the programmable Dyna 2000 I would say...

I know a bunch of people that have them on cars (also megasquirt for fuel injection).

http://www.autosportlabs.net/MegaJolt_Lite_Jr.

[hazez24]

No, I did not switch to mechanical advance

Haze,

did you run a mechanical advance setup?

[Mista M]

Try with a mechanical setup. It wont work with electronic. Im running a setup off 1979 750.

[spyug]

As I mentioned in a post yesterday, I did get it to run. It will start with choke and will idle when warm. It is firing on all cylinders and the pipes heat up fairly quickly.

It will not rev up. The signal generator is in the stock position and I haven't, as yet, slotted it to allow repositioning as suggested. I'm thinking there is something wrong with the advance but since this is controlled by the igniter, I'm not sure what could be happening.

The carbs were rebuilt prior to the igniter project so I'm fairly certain they are fine and not part of the problem but I'm now lost and in need of some direction.

Any ideas or suggestions folks?

As always I appreciate any and all input.

cheers,
Spyug

[JEEPRUSTY]

Does the 550 rotor have the same markings in the same locations as the 750?

Just wondering if the mounting plate need to be slotted in order to match the config on the 750.

Slot and do the timing thing the gurus suggested.

Oh and the tab on the rotor, is it situated at the same distance to the pickup coils as it was originally?
If it is not exactly the same would that not produce a weaker signal to the ignitor, one that has more signifigance with an increase in RPM?

[chef1366]

If you're positive the igniter has the built in curve than possibly it's bunk?

[Mekanix]

Pipes heating up quickly? Seems like its way retarded and using the excess fuel just to keep running.

Does it backfire or bog when you rev it?

The pickup position might look the same as the 750 does but what position is the 750 crank in conpared to the 550?


I mean if the pickup rotor is pointing straight up and down and say for argument sake the #1 piston is at tdc on the 750, IS the the 550's crankshaft in the same position with the rotor pointing in the same direction...


I guess where I'm going with this is, I think the ignition is too retarted (pipes heating up too fast)

and I'm thinking the ignitor was designed to expect the crankshaft to be in a certain position but its not.

Now that your using this ignitor setup on the 550, the crankshaft might not be aligned the same way the 750 is so the ignitor is thinking it should be firing when the #1 piston is at TDC but the 550 crank isn't aligned for the #1 piston to be at TDC, in fact its already gone past that...


Something that would help you would be a couple of pictures.

1 of the 550 with #1 piston at tdc while looking at the ignition cover side with the rotor removed (paying attention to the locating pin on the crankshaft)

And 1 of the 750 with the #1 piston at tdc looking at the same thing.


but hey if they are both ligned up the same way then my theory goes out the window

and we're back to

If you're positive the igniter has the built in curve than possibly it's bunk?

[pete]

I'd also be saying timing, and I think the suggestion from Mekanix to compare the two cranks is probably a very worthwhile comparison to make and that's the only obvious way I can think of to see if there's some difference.

[Matchless]

I would stick a timing light on there to see what is happening. Also compare the TDC mark with the piston. If you have a dwell meter it would be good to check your dwell angle as well just in case.

[spyug]

Well both ignitors I have work in my 750 so i doubt they are a problem.

There are no timing marks anywhere in the 550 so I can't check anything with a timing light so that leaves me checking the rotors with the #1 pistons at TDC so that's what I'll do next.

I'll let you know what I find.

Thanks for all the input and suggestions.

Spyug

[Matchless]

Well both ignitors I have work in my 750 so i doubt they are a problem.

There are no timing marks anywhere in the 550 so I can't check anything with a timing light so that leaves me checking the rotors with the #1 pistons at TDC so that's what I'll do next.

I'll let you know what I find.

Thanks for all the input and suggestions.

Spyug

Could you try making your own TDC marks and then see how close you are with the timing light?

[chef1366]

Are you sure the cam chain is timed correctly?
Even off four degrees it should take throttle.
Are the slides lifting on the carbs?

[spyug]

Well I guess I never listened when my old dad used to say, "when in doubt, read the instructions". I should have read my 750 manual because it clearly shows the timing mark on the rotor that aligns with the pickup coil for 1&4 (left side in the pic above). I don't know how I missed that. Such a stupid oversight. I remember now checking this on my 750 Kat build last year so I should have checked it on this project. Just dumb on my part

As suggested by my good buds Mekanix and Pete I found TDC on the #1 cylinders of both the 550 and the 750 and compared the rotor positions.

Just as they thought, the position is off on the 550. The timing mark should line up exactly with the pickup coil but it is actually a few degrees behind. The "contact" on the rotor is just on the pickup at TDC. The mark comes once the contact clears the pickup. The plate will need to be slotted and it turned counterclockwise to bring it into correct alignment.

Sorry but I don't have access to my camera at the moment to show but I will record this in my tutorial once I publish (and when the damn thing runs right).

Thanks for pointing me in the right direction guys.

Cheers,
Spyug

[spyug]

On the subject of carbs, I did notice that cylinders 3 and 4 are not firing properly. There is ample spark but seemingly no gas is going in as the plugs are sparkling clean. 1&2 are both sooty so likely getting too much gas. I guess I'm going to need to pull them off and clean them again. Dang.

Well I guess we're finding the issues....now all I need to do is fix them.

Thanks again,
Spyug

[JEEPRUSTY]

may I politely suggest ou change the needle valve o-rings,
Just got finished pushing mine 1.5 miles in 2 hours.

two people stopped to offer asssitance
2nd guy said hey maybe its you carb o-rings