Topic: Power loss after warm up. Need help!

[hawkman]

CB750F 1976

Bike starts right up, idles great, get on the bike and take off....

After about 5 minutes, it loses about 50% power.   I gas the throttle and it accelerates very slowly with strage low pitch engine sound.

It almost feels like it loses a few cylindar.

I think it is ignition related.

Anyone have or had a similar problem, and what the problem was?

Any suggestions?

[clarkjh]

coil?  I'll let TT chime in about the regular tune up stuff

James

[HondaMan]

Me, too. A bad coil can do this after warmup.

Also, intake valves that don't have enough clearance can do this. Check valve clearances.

Finally, points gap can do this. The gap, if too small, becomes even smaller when the engine warms up, especially if the pivots are gettting worn (presuming, of course, you still have points..). 

[hawkman]

How do I check the coils, and if needed, where can I get them other than the dealer?

thanks.

[csendker]

Testing coils --> http://www.sohc4.us/forums/index.php?topic=5752.msg8383#msg8383