645 blizzard vacuum

buzzard82
New Member

Posts: 32

645 blizzard vacuum Mar 12, 2023 17:26:44 GMT via mobile

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Post by buzzard82 on Mar 12, 2023 17:26:44 GMT

Hello all rebuilt the carbs on my 71 645 new fuel and vacuum lines. Only fires on spray. Choke it and it will start on mag side only.

I noticed when i got it case halves all wet. I put a vacuum gauge on it and it makes 5inchs cranking. Same gauge on my 775 makes 10-11 inches cranking.

Almost sounds now like compression escaping somewhere pto side. That plug fouled too.

Im assuming it needs 8-10inchs in order to open the needle in carb correct?

Thanks

Assuming it needs to come apart and be resealed.

Compression throttle open 6 pulls each
Mag 150
Center135
Pto 145

Center cyl is 20 over

Last Edit: Mar 13, 2023 2:03:29 GMT by buzzard82

olyman
Global Moderator

Posts: 709

645 blizzard vacuum Mar 16, 2023 16:18:13 GMT

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Post by olyman on Mar 16, 2023 16:18:13 GMT

compression isnt even, but its not that bad and has more than enough to run.

If you have damp cases then you have a leak without doubt. If it hasnt had the base gaskets sealed up since then they will leak again.
Or its leaking between the case halves, and/or the seal(s) is leaking too.

Fix the leaks and move on from there

Last Edit: Mar 16, 2023 16:19:01 GMT by olyman

buzzard82 New Member Posts: 32	645 blizzard vacuum Mar 18, 2023 16:16:13 GMT via mobile Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by buzzard82 on Mar 18, 2023 16:16:13 GMT Yup next step is teardown and send crank out to get some 454 rods installed.then reseal it.

Post by buzzard82 on Mar 12, 2023 17:26:44 GMT

Post by olyman on Mar 16, 2023 16:18:13 GMT

Post by buzzard82 on Mar 18, 2023 16:16:13 GMT