Pulled the carbs out in my first attempt at cleaning them (think I did a pretty good job) replaced air cleaner and got new spark plugs. Put everything back together and all I get is a bunch of backfiring. It sounds like its soooo close to starting but just backfires. Anyone got an idea?

thanks

 

Are you sure you have the spark plug wires in the correct order?

 

Yep, just checked em again. They're connected in the same order they were before (aka pre-everything aka when it was working lol). Can backfiring can be caused by too rich AND/OR too lean of a mixture? From what I've gathered I may need to tune the carb, when I cleaned it I removed the jets and cleaned them and put them back in but didn't touch the adjustment screw...

 

I just pulled the carbs out again, I was advised to use an air compressor to clean the carbs and that there is probably still some gunk in the jets

 

I'm not sure what "adjustment" screw you're referring to, can you be more specific ? After cleaning the carburetors, it's often hard to get fuel into the bowls and full. It can take a lot of turning over, and can drain a battery while doing this.

Something I do after having the carburetors off the bike and the bowls drained is to follow the procedure in the shop manual on page 18-17 (chapter 18, page 17) for bypassing the Fuel Cut-Off relay. It's under the Discharge Volume Inspection. This will cause the fuel pump to run continuously when you turn the key on. This should prime the carburetors and fill the bowls. Make sure you put everything back. You only need to let the pump run for about 10 to 15 seconds and you're done.

 

Well I got it started, but it still backfires infrequently. I also noticed a substantial loss in power... my mechanic buddy said my timing is probably off, anyone know how to check that?

EDIT: Still reading other posts and noticed that when I cleaned out my carbs, I neglected to remove/clean the D-shaped pilot screw and didn't take off/clean the black parts that hold the gaskets/needles in them. If those were real dirty and gunked up would that cause the power loss/backfiring?

 

No, it's not the timing being off. Not to say that it may not be firing at the wrong time or order. If that's what it seems like, then I have to say go back and check the plug wires and the wires that connect to the ignition coils. Timing is not adjustable on the F3's (not without aftermarket parts) and is controlled by the ICM.

Both coils have a Black/White wire going to them. The coil that fires cylinder #1 and #4 has a Yellow wire with a Blue stripe. The coil that fires cylinder #2 and #3 has a Blue wire with a Yellow stripe. Their close together and easy to get mixed up. Also, the plug wires are numbered, verify the right one goes to the right plug.



I'm a firm believer in doing things right the first time. If you're not taking the carburetors completely apart, then it's easy for people to miss things. This is how they look when done fully.

 

Ohhhhhhhh man. Thank you so much for the pics and everything. Just got it running, you were 100% right my plugs were outta order, I didn't even see the numbers on the cables.

 

Well congratulations on getting it running again. I'm sure it feels good. Sometimes you just have to take a moment and verify what you're looking at and what it's supposed to look like.

Very good...

 

There ya go!