Pipes 81 cb750 dohc

[jmac]

Hey guys I want to chop my mufflers one is cracked right by the foot peg anyway so I have to do something. Will a straight cut efffect the motor, like burn the valves? Also I am having idle problems, the previous owner said bad gas any simple things to check other then draining the gas which I am doing this weekend.

[TOOLS1]

Cutting your pipes might require you to rejet your cabs. For the poor idling, try putting some Seafoam in the gas.
TOOLS

[Re-run]

As tools said, rejetting may be needed but I doubt you would burn a valve unless you cut within a few inches of the head.
It is hard to say what jetting may need to be done, if any. Exhaust changes are more flexible than intake changes though, going straight might be enough though.
You might take it in to be welded, brazed. At least till you can get a new exhaust system or slip ons for your headers.

[jmac]

Thanks guys for the info

[jmac]

Alright pipes chopped, rear suspension off ready for lower struts, tank and covers off ready for primer and paint, chain cover off, now for my latest questions...... OK so can I put my 1979 single disk break system on my 1981 model cb750 fairly easily? I am painting my mag wheels an orange red and want to show them off as much as I can so wont to lose the dual disk in the front.  I am painting most of the tank and covers black. Any tips on using engine enamel rattle cans for paint?

[Cabreco]

jmac wrote

Hey guys I want to chop my mufflers one is cracked right by the foot peg anyway so I have to do something. Will a straight cut efffect the motor, like burn the valves? Also I am having idle problems, the previous owner said bad gas any simple things to check other then draining the gas which I am doing this weekend.

Jmac, on my old '72 CB500 Chopper I had drag pipes that came just past the shifter with no real issues. I used to use chicken wire inside the tubes as baffles to give it a throaty sound.

[jmac]

awesome pic thanks

[Cabreco]

When you fire her up with the cut off pipes, let us know how it sounds.

[Re-run]

OK, so you want to put the single disk from a 79 onto the 81? Well, that should fit fine but to make it as easy as possible, I would swap everything from the forks, down. Your triple trees should work fine but switching the forks with the whole assembly would be easiest... If both wheels are mags.
As for paint, well rattle can might be ok. Prep the wheels very well. Get them sanded down nice and clean and then wipe things down with rubbing alcohol to clean any particles off. Lay a couple thin coats of primer on and lightly sand between each one by dipping fine sandpaper into water and gently rubbing.
 After a few coats of primer, then you should be able to lay paint. Masking will be the worst since you want to 2-tone it.

[jmac]

Tahnks for the info. I will have to switch the wheel the older bike has spokes  Thanks again