When going down the highway at average 80mph she eventually dies. Wait awhile on the shoulder and she starts. Never hassles when using side roads only highway cruising. So would think fuel not getting to carbs under constant heavy load. Changed fuel filters in case they blocked but suspect fuel cap breather as it hisses big time after a run. Cleaned the cap twice by stripping and using carb cleaner and compressed air but still get hissing noise after a run.

Has to be the cap Mc, if it hisses like a snake then your going to have to strip it back and see if the hole is blocked, other wise just drill it a bit bigger.

Also check that the sealing rubber is not positioned wrong, some need to be in exactly the right place to work correctly, should be a ridge around the out side that has a break in it to let the air in.

Edited August 20, 20159 yr by slice

Take it out a run along your highway. When it starts to fail release the fuel cap....That way you 'll know if it's the cap

Edited August 21, 20159 yr by jimmy
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