Just curious, if the bike dies and you try to restart, do you keep cranking till it starts, or do you wait a minute, try again, and repeat? I'm wondering if the bike would fire if you push started it? Also wondering how fast it cranks? (battery issue?) Also maybe wondering if the fuel line isn't blocked a bit??

Just cutting out doesn't make any sense unless it was always after you rode through a puddle or something.

Oh, check the starter kill switch. On mine, even if the switch is in the right position, if I bump it ever so slightly, the bike will cut out. IE, if the switch is down and I hit the part that is down, the bike will try to kill, but then stays running. as it is only a temp bump. If I tap it a bunch, the bike will die and I have to restart.

<Edit> since the side stand switch can also cut the ignition, make sure that switch is operating normally. If it cuts out right after a bump or when you shift, maybe you are accidentally doing it.

 

Ok, when it cuts out, it's like it's running out of gas.. and when I try to re-start it, I try for 10-15 seconds, wait for 30sec-1min, try again, etc.. It turns over just fine (speed wise) and sometimes sputters, but won't re-start immediately.. I took the tank off this weekend and blew through all the lines to make sure nothing was clogged. I haven't been able to re-duplicate the problem, since it never sits outside at home. Hopefully sometime this weekend I can put it outside for a few hrs and see if it'll do it again.

 

On second thought, maybe I should try to find another petcock. Maybe something in there doesn't like the heat?

I took off the vacuum line that goes to from the engine to the petcock and sucked on it and gas flowed out the petcock just fine, on both reserve and normal.

 

My money is on the fuel issue. Clean the carbs and drain the fuel. Put in new fuel and go ride

 

I've had 3 tanks of fuel in it so far, and I've looked at the carbs, and they're clean..

Odd thing is, it only does it once per ride.. after about a mile.. then after it re-starts, it runs fine for however long I ride it (30+miles).

What about vapor lock? Since it was sitting outside in the sun on 2 90+degree days, could that be a culprit? And if so, how do I fix that?

 

to be honest i never even heard about it :-)

 

Doubt it's vapor look since the fuel line is vacuum assisted and you did test it out. I have limited experience in this, so take this with a grain of salt. Maybe you are running too rich or something. The fact that you run it a mile first...means it's cutting out as it warms up...but once it is completely warmed up it is fine. I'd pull each jet to make sure they are clear. Also check the plugs. I saw a link on here how to read the plugs. How's the temp of the bike when this occurs? does it seem to cut out at the same temp? I personally don't know what it means if it does, but someone here might. How long do you let it sit before you go off riding? Maybe one of the needle valves sticks at a certain temp? Maybe the diaphragm is screwed up? Maybe you need ot synch the carbs? Check the valve gaps?

Maybe check "Dan's Motorcycle Repair Course" (linked in this thread: https://cbrforum.com/m_350599/mpage_.../tm.htm#350599) for possible troubleshooting tips.

 

Well it only seems to do it when the bike has been sitting out in the sun all day at 90+ degrees outside.

I rode it last night for a few miles, and it was just fine.

 

no kink right?

 

nope.. no kink at all.

I'm in the middle of moving, so I haven't been able to test it since I had the body work/tank off..

Next week sometime, I'll leave it outside for a few hrs in the sun and see if I can duplicate the problem..