Fire in the hole

[DVL1000]

Hello All,

I rebuilt everything on my 78 including the engine. (Getting 165 to 170 psi on each cylinder). Anyways, I went on a ride (50 miles) and when I returned the LH sportster muffler was glowing inside. Is this a sign of timing or bad carbs.

Thanks,

David

[salukispeed]

Are the sportster mufflers you are using of the catalytic converter type. If so you could have a rich condition and that would cause the ceramic matrix to run red/orange hot. Also retarded timing can make the exhaust run terribly hot. a lean mixture can also run hot. But if using new bike take off mufflers i suspect they are cat type.

[DVL1000]

Hi,

One side is not hot at all. Never thought of cat mufflers, thanks I will look into it. I am suspecting it is raw fuel, I will also look into advancing the timing, I am using Dyna.

Thanks,

David

[Track T 2411]

You could temporarily swap the muffs side to side (if you didn't weld them up) and see if it follows.
Don't just advance the timing, make sure it is correct rather than adjusting it to cover up the real problem. First simple tests would be to check header temps to make sure all cylinders are firing, check for spark at each plug, and pull the plugs and read for color.

[DVL1000]

Thanks. I'm going to recheck everything and try another set of carbs. Never thought of switching mufflers so I will try that too.

[tlbranth]

Same thing happened to me. I have Bonneville mufflers on my '75. I rebuilt the carbs a while back using Randakk's kit and dvd. #2 was fouling plugs and the left muffler melted my saddlebag and discolored the chrome. I've had the whole bike apart for 'remodeling' and checking the #2 carb fuel level was on my to-do list. What I found was, I'd left off the plastic gasket that goes under the round thingy the piston rides in. I'm pretty sure that's going to be what the problem was. Haven't got the bike together yet so I'll have to see. You might check that though. Also, just take a look at the plugs.

[DVL1000]

Hi,

Replaced the carbs with another set. Very strange, plug #2 was still wet. Re-checked the timing and valve clearances. I also checked for spark (all sparking).I then swapped plugs and started the bike and started to pull plug wires. At idle I can pull #3 and # 4 without changing the idle but will not rev up. With all spark plugs connected it revs good. I checked the advance and it seems Ok. I'm using DYNA with gl1000 coils.. any ideas????

[ericheath]

You have spark at 3&4 but no idle, so it's likely not enough fuel or too much fuel at idle. They're not wet so likely not enough fuel. Try turning the idle/air screw on those two carbs out a half a turn at a time to let more fuel mix in. If no change, you have not enough fuel getting to those carbs at idle.

If your floats were set really low it might cause this, but more likely it is a still plugged idle circuit.

[DVL1000]

Thanks, that makes sense. I'll let you know how it goes.