Engine Backfire

[Noodes7792]

Recently installed a MSD enhancer and Coil, New B-pipe with true Fx-1 chamber, Girdle ADA head. Ski is trying to start but Backfiring like a champ. Any direction would be much appreciated. Fever!!

 

[Noodes7792]

oh and this is on my Fx-1 with 61x motor

 

[Noodes7792]

im guessing its a MSD wiring issue. As i look through the wiring diagram i am noticing there are multiple white to white and green to green connections. Could i possible have those two mixed up. Or bad enhancer

 

[Quinc]

Go back over your wiring. There is a thread on here somewhere that has directions.

 

[Noodes7792]

I've gone over it and still can't figure it out

 

[Noodes7792]

Heat sensor black and pink wires have been taped off

 

[Harbor]

What happens if you swap the spark plug wires @ the spark plugs front to back and back to front

Another long shot for ya, sheered woodruff key on the flywheel

 

[Noodes7792]

U mean at the head. Switch the plug wires? Didn't try that but the shorter one is on the rear plug. Followed that diagram to the T

 

[Harbor]

I couldn't remember if the plug wires on my MSD coils were equal or different lengths that I had to guess which one went to front cylinder.

So if one is shorter, it's the rear and you've prolly got that right

What about the woodruff key?

That coil and enhancer look new ?

 

[Noodes7792]

Yea it was used on a ski prior maybe 10 rides then sold to me. He said it ran great on his ski

 

[Harbor]

Quote: Installed a msd enhancer along with head and pipe. Slapped all back together and hit the start button and just heard the starter spinning. If I remember right the bendix is spring loaded so it would have nothing to do with the fact I replaced the Cdi. It spins and spring seats that then grabs the flywheel. Just making sure I don't have Cdi wires crossed and it's just the bendix. Thanks.
Noodes7792, Yesterday at 7:03 PMReport
#1LikeReply

I see you were in the flywheel area already, could have the woodruff key fallen out ? Or just sherd

Edit: read a little further but didn't see you had the flywheel off just a free wheeling starter my bad!

 

[Harbor]

Woodruff key times TDC of the flywheel to TDC of the front Cylinder. If the flywheel slips out of time the Cdi will not know the crankshaft position and spark will happen at the wrong time or on the wrong cylinder causing backfire

 

[Noodes7792]

I did go in there but was looking at the bendix and did not take the flywheel off. I was looking at what and if I had an issue with the bendix. For whatever reason I took cover off and held the bendix to see it operate and boom it engaged. Put cover back on and then noticed the backfiring. Ski did not run prior to removing cover. Correction. Ski ran great prior to adding head, pipe, and msd

 

[Noodes7792]

Guess I could easily pull the flywheel and see

 

[Tyrant1919]

The two sets of green to green wires can be plugged in either way. Swapping the spark plug wires around does nothing. They both fire at the same time.

Quickest way to find out what's up: put the stock ignition back in and see if it backfires. If it doesn't, then the MSD is your problem. If it does backfire, then you have an issue elsewhere. But step #1, swap your stock ignition back in.

 

[Noodes7792]

10-4. Thanks for the help

 

[Magyar68]

When Mine was doing this it was the stator. Pulse Coil out of spec.

 

[Quinc]

Double check the red wires, (it is easy to mix those up) check the fuse, and make sure the ground wire is correct.

Pics are gone but the instructions are still there:
http://www.x-h2o.com/index.php?threads/how-to-msd-enhancer-install-pics.21086/

 

[Noodes7792]

I'm thinking it must be the cdi. I am swapping it back to stock this evening and checking. Noticed compression is around the 165 range on a brand new ada so I hope i didn't blow any o rings with the backfire. Thanks for the help will report back.

 

[Harbor]

^^^^^ the green wires are for the regulator and connect in no particular order "either or on those" btw