Cranks and Backfires but won't start

[dinger]

After scouring ebay, it looks like a 90 CBR600 generator is the same style - hopefully i'll have a new (used) one this week.

Thanks everyone for your suggestions.  I'll let you all know how it works out.

[dinger]

Well, good news and bad news.

Good news is, if anyone has pulse generator issues a 1990 CBR600 pulse generator fits in the CB-1 engine cover.  The bracket inside the case and the wire harness plug need to be changed to the CB-1 stuff, but it bolts in without modification.

The bad news is, i'm apparently not one of those folks with pulse generator problems.  Installed the new generator, same crap.  Backfires, pops, but does not start.

I'm about ready to dump this cycle into a large, deep body of water.
 

[xstreamcanadian]

hey dinger

did you ever get this sorted? I am having the same issue. The thing is, mine ran ok, a little boggy with low rpms when cold, so I tore the carbs off to re-clean them, and made sure the idle jets were spotless, and now she wont fire up....

[dinger]

I never did solve this one.  I just received a pair of coils the other day that I am changing out as a last ditch effort.  The bike was at a shop for 4 months and they just finally gave up and gave it back.

I've replaced the crank trigger (twice) , coils (once), cdi (twice) spark plugs (twice), checked the harness, fuses, cleaned the carbs, made sure the cams were in time with the crank.

I'm at a total loss.  I'm about to give up on her and part her out.  

[Serados]

Let me know please how that goes, ive got roughly the same problem

Edited: Misread and thought this was the tech problem i posted

[dinger]

So, I had a buddy drop by last night for an unrelated reason.  He has built a lot of small block chevys and I though I'd let him listen to it. 

He made the comment that it sounded just like a chevy with the distributor in 180 degrees out.  I double checked that I had the wire harness wired to the primary side of the coils correctly, just as in the diagram out of the factory service manual.  Still had the issue.

So I said "what the hell?" and switched around the Bu/Y and Y/Bu to the wrong coils, backwards from how the manual shows.

And it started.

Is this a misprint in the FSM?

[clarkdw]

You are correct. The wiring diagram shows Y/Bu connected to coil 1-4 and Bu/Y to coil 2-3. The picture of the coils on pg 15-7 shows the opposite.  Good on your buddy for picking out the symptom correctly.

I sure hope that the bike runs great for you now.

[91cb-1]

Holy crap after all of that it was misplaced wires, that's something you're never going to forget, and hopefully there'll be plenty of people on here who will be able to learn from that!
Glad to hear you got her running again, back to the pure thorough bred enjoyment of the -1, just in time for winter...

[Jassen]

Aww, man, I was reading this thread because I'm having the EXACT same problem, and was all excited thinking it would have my solution. But alas, no, because I didn't touch anything between it running and it not running. Wednesday evening my '89 CB-1 was purring just fine, yesterday morning, she wouldn't start. But exact same symptoms as described here: Turns over just fine, will occasionally fire off for 2 seconds or less then quit, and is backfiring out the exhaust like a shotgun blast, but she just won't run. I have spark, I have fuel flow, have tried all the standard choke and throttle tricks.

Back to the searching I go!

-Jassen

[a_morti]

My bike died on the way to work this morning  felt like it ran out of fuel. I coasted to the side of the road, then set it on the main stand, stepped back and scratched my head for about 3 seconds before stepping forward, rotating the petcock, starting up and riding away 

[MinkeyMaster]

hi dinger
i hear it's worth a try to remove the rectifier,clean the back thoroughly and the part of the frame it attaches against.
then apply  thermal compound as used for computer processors.
then re-attach the rectifier firmly.

Chris