carbs

[IrishPatrol]

Did the 69 patrol come with different carbs other than the hitachi? GM rochester maybe? That appears t be what I have. doesn't seem to be easy to Tune.
Backfire! any ideas?

[Esteban]

Some other might have a better idea on what type of carbs were fitted. My Patrol came with me from overseas.

Regarding backfire, in addition to timing, it's possible that the acceleration pump is not working properly, so when you open the throttle, no fuel is injected to the carb by the acceleration pump, causing the backfire. Low fuel level at the reservoir can also cause this.

I found this troubleshooting guide for carburetors:

http://roncrawfordsholleyrebuilds.com/c ... oting.html

Good luck. Post some pictures of your carburetor.

[RiverPatrol]

The '69 did come with the GM Rochester carb. The switch was made from the Hitachi in about '67. You can still find rebuild kits for the Rochester, it was a common carb used on several GM products.

Backfire can also be caused by the points adjustment.

[IrishPatrol]

Thanks you guys are awesome! I'll give it a try. do most of you run the mechnical fuel pump (original) or have you went to the electric? I have the original on there plugged at both ends and a elevtric one was installed. Like the idea of an original. Any advice here?

[RiverPatrol]

I run the original mechanical pump. Just personal preference.