1983 XL600R - Clean Carb, New Stator, Good Spark - No Start!

[jonbobshinigin]

As title says...I went through a lot a while back trying to figure out a hard start issue. We cleaned the carb, replaced stator and she was running very well until one day it just quit (probably only a couple hours worth of riding). Since then I have checked spark, which is still good, cleaned carb. flushed tank, and adjusted valves. The only variable with the work I have done is the valve adjustment. I did not have the right angle on the clearance tool so I am not sure they are perfect. They were "tight" so it is better now, but perhaps not perfect. What else can this be??

[Horri]

Hmm,,Dunno tbh..So you were just riding along and it stopped,,Does this sound correct, You weren't thrashing

the heck out of it or anything at the time.??? Even though you still have spark I'm still tempted to say possible

CDI issue..You don't need to have a completely flogged out one that produces no spark what so ever to maybe

have a running issue,,This is just a guess,,I am not saying it is the problem. As far as I'm aware you have a couple

of these bikes..If you have a spare CDI swap it in from the other bike..

Edited May 13, 2014 by Horri

[jonbobshinigin]

No thrashing at all...we were stoked that it was so easy to kick over for a couple days after the repairs. Then I went to take it for a ride and it just cut off. It still kicks over fine and has bright spark.

We have swapped the CDI with another from the other bike. Prior to this issue BOTH CDIs did in fact work so I do not expect that to be the issue. We did swap it and it changed nothing.

Thanks for the help. I'm thinking it is a compression issue?

[brendo907]

just wanna check did you use a new spark plug? i have had many times (especially with old hondas) that the spark looked good but wasnt enough to light it up. its 2 bucks, its worth a try. Also make sure the spark plug cap is tightly threaded onto the wire. Or unscrew the cap and nip the wire and re thread for a fresh fit. for compression on a budget i usually just pull the plug, put my thumb over the hole and have someone kick it over, if its enough to push air around your finger it should run or have some farting or popping. 

[Horri]

A compression issue huh..Well I guess you could disconnect both the kickstart decomp cable and the one that goes to that 5th

valve and just use the handlebar decomp lever to get the bike to TDC so you can kickstart it..That;s if I'm thinking correctly

on how the system works..As far as I recall neither of those cables are needed to get the bike to start. If you then use only

the hand operated decomp with the kicker you should be able to feel whether you have enough compression to get the bike

to start by trying to kick it over without using the hand operated decomp. If you stand on the kicker and can't get it to go down

to me it means it has more than enough compression. If that's the case pull in the hand job and line her up at TDC and try starting it

using the stock method for bikes without an auto decomp or the excessive cable system..

Edited May 13, 2014 by Horri

[jonbobshinigin]

We have tried starting with the decompression lever and kick link out of the circuit and still no start.

[Backwoods-Bomber]

After a bunch of kicking is the plug wet?

[jonbobshinigin]

It is a new plug and I am pretty sure the plug is wet...the carb that was on it before caused a wet plug but no start. We cleaned out the extra carb very thoroughly and just put it back in. I need to check again for wet plug however.

[Horri]

Perplexing issue..If spark and fuel you should get some sort of fart at least from kicking it over. Don't know what to suggest .

Best I can say is go through the timing and rocker gaps again..(TDC compression stroke).,T on it's mark,.Piston top of bore..Lobes down..

check gaps..That's all I have..Maybe pull the top cover and have a look and see if the timing marks are still correct on the top Cam sprocket

in relation to the datum marks and head and the T on the flywheel,,No idea why they would suddenly shift unless the Camchains jumped a tooth or something..

Oh yeah ,,check that the keyway is still in the flywheel/Crankshaft slot..Maybe it's snapped off and thrown the entire timing out..That'd shag the entire

timing up completely..Other than those few things I dunno,,maybe pulse genny issue (Clutch side front of the motor),, wires hooked up to it..maybe swap

in your spare..I've never had one fail but who knows..

Edited May 14, 2014 by Horri

[Oldtech]

You're not alone here. I rebuilt my 83 over the winter and pulled it out a couple of weeks ago. Kicked it through a few times to prime it, turned on the ignition and if fired up first kick. I took it out for a spin then turned it off and haven't been able to get it to start again. Shoved it to the back of the shed in disgust and will pull it out when I get the cb550 I'm rebuilding finished. There's good spark but I tried another CDI anyway. The plug (new) isn't really wet so I'm guessing a fuel problem.

[jonbobshinigin]

Just swapped the CDI and she fired right up. Idle isn't perfect but I'll keep working on it and post back!

[jonbobshinigin]

Deleted

Edited May 18, 2014 by jonbobshinigin

[Horri]

Just swapped the CDI and she fired right up. Idle isn't perfect but I'll keep working on it and post back!

Er..Didn't you do that about 6 posts back and say it wouldn't go or nothing changed..Whys it suddenly running now??,,Did you get

a new CDI or have the other wired up wrong..You can't just use any old CDI in bikes..They have to be the correct one for the

machine unless someone tells you that they know for sure a different models CDI will work.

[jonbobshinigin]

I did it a while back and nothing changed. Funny thing now is this...I had solid blue spark, and it wouldn't start. Then my friend decided to swap CDI and that's what got it started after having not run for some time. So I checked to see what spark looked like with this CDI, and it's a weak yellowish spark!

[jonbobshinigin]

Okay, it's not starting up easily when cold and running for 3-10 seconds or so and then it cuts off. This is without choke. We started it today 3-4 times. When we turned the choke on it idles for a good 10 seconds well, then died. After that, we cannot start it again until it sits for a bit.

Carb is clean and we drained the tank and have been checking the jets. What am I missing?

[jonbobshinigin]

Bump! Help?

[Horri]

Don't know..If the jets are clean and the tiny holes on the sides of the emulsion tube and pilot jets side tiny holes are clear I have no idea. If it was a gas problem it should still run for longer than 10 seconds on a carb of gas,,a minute would be the minimum run on a carb full of gas. Sounds electrical

but as to what electrical I wouldn't know..