Hey there everyone!!

I have a 1989 CBR 600 that I have been working on. I have a thread there showing how I got the bike and with you help I had it running in December...

little back story... Got the bike... got your help and I got it running. I blew it apart so taht I can paint and clean it... Fast Forward to today.

Got the harness in the bike, hooked up everything but it will not fire.

I pulled #1 plug and checked that it does have spark. I have the carbs attached and I am using gas in the velocity stacks and/or starting fluid as I crank it over.

Checked compression and it has that too.

I got the schematics to verify what wires went to what coil and verified that the plug wires are on the proper cylinder. Even checked fuses, grounds and harness connections.

Nothing I do will make this big biach fire. its not even trying...

I didnt cut or in any way modify the harness so I dont understand why it worked before I took it apart and now that its back together it does not fire.

Anyone have some advice for where I should double, tripple or quadrouple check?

Thanks Everyone! Sorry there is not much to go on here.

Just as an FYI I the following setup on my coils...

 

Sounds like you covered most of the basics already. I would check spark on the other 3 cylinders too, to verify that both coils are firing. Assuming spark to all 4 cylinders you can pretty much rule out any ignition system components which makes it easier.

Did you do anything with the carbs while it was apart, and is the choke functioning properly? You might want to pull a plug after cranking it for a bit and check for evidence of fuel in the cylinder, or drain the bowls & make sure they are full. Assuming the compression is good since you mentioned it already, were they all pretty much even and close to max spec?

If you have a good spark to all 4 cyls, and the compression is good I would be looking for an air/fuel issue. Air leak at the carb boots or the spacer o-rings, carb issues, or fuel pump not filling the carb bowls.

 

I can pull the other plugs tmr. I got mad so I decided to take a break. I dont have the fuel system hooked up. Just shooting starting fluid, either, down the carbs to get it to pop off before going further. When I break bikes down and rebuild I like to verify it will fire while I still have decent access to the harness and other systems before wrapping up.

The only thing I did was take the bike apart for painting. Kept motor and trans together. No electrical mods. It just baffled me so im calling the old man, 38 yrs in Local 701 as an auto technician. Between the two of us idiots we have not had a project we couldnt fix. Im just burnt and blind so im here for suggestions. Its the worst when ur ******* deep in a project and after looking at the same thing for months I cant see whats probs right under my nose.

Any and all other suggestions from u all is welcome because I am stumpped.

Cheers

 

I would try an inline spark checker. They are like 5 bucks from Harbor Freight and not much more at local parts stores. That is the easiest, quickest way to tell if you are getting spark to each of your plugs.

 

I had this same sort of issue. Rode my bike home after I bought it. Did a bunch of work to various non-engine/ignition stuff and when I went to fire her up - notta. Ended up being a carb issue. Cleaned it really well and bench sync'd. Put her together and she fired up.

My money is on carbs.

 

So my dad offered to come help but its not going to be till Thurs. Check back with yall on Thurs or Friday