Hey everyone, I have done some mods on my 2000 FXDX 88ci and the bike won't start.. Here is a list of what I have done:

- S&S 106" flywheel 4 1/2" stroker kit
- S&S 106" piston kit (3 7/8") and ported my cylinders
- Feuling Parts 543 camchest Conversion Chain drive with adjustable pushrods and Econo valve springs
- Jims quick compression release
- Mikuni HSR 42
- TBR Comp S 2-1 Exhaust system.

The bike wouldn't crank at first because of too much pressure in the engine. Jumped from a 9:1 to a 10.1:1 compression ratio. Installed the quick compression release. Bike cranks fine but doesn't start.
Upon installation, I checked by hand that the crank rotates easily. It doesn't seem that there is any issue when installing all the parts. Also cranked the bike without spark plugs and it does seem to run nicely.

My only thought at the moment is that the stroke of the crank has changed now. Would an aftermarket ignition module fix the issue? Or can it be something else?
I'm tired of waiting and getting more and more parts only to find out I need more parts for the bike...

Appreciate any help anyone can give!

 

The stroke dimension is irrelevant

You need to determine what you are missing:
SPARK ?
or
FUEL ?

 

I have both spark (tested the spark plugs with contact on the heads) and fuel (carb squirting properly) . There is no problem there. I also have a good compression (test done).

 

Are you getting enough fuel? Put the plugs back in, take off the air filter and spray a little carb cleaner into the carb while starting. Watch out for intake backfire.

 

Yes, after multiple cranks, I am getting backfire from the exhaust which means that there is enough fuel flowing inside the engine

 

It sounds like it may be a timing issue. I don't know how the ignition is set up on this model but could it be possible that the plug wires might be reversed? I know some of the older models both plugs fire at the same time, these I'm not too sure.
Also that ign module could be the problem but I wouldn't trash it until I rechecked everything.

 

Another thing to check is to see if the plugs are wet with gas after trying to start it a few times. If the plugs are dry and the bike isn't firing it's a fuel issue. You said the carb squirts fine, that just means the accel pump is working. If your carb isn't delivering fuel apart from the accel pump then you have a carb problem.

 

The spark plugs were wet so the carb is working fine. I do believe it might be a timing issue as well as the stock ignition module is set for sparks at certain times for the oem flywheel. Now that I have a stroker flywheel, wouldn't I need to adjust the timing of the sparks?

 

I'm not too sure, you might want to contact S&S and throw this past them.

 

Agree with JustDave13 on the possibility that plug wires could be reversed. If the motor turns over, i.e., "cranks" has fire and fuel, back fires but does not start, that is the classic reaction when plug wires have been reversed and a common error with new builds.