Hello,
Have a 1976 JS400 and seem to be having caviation/pump issues. Got it running good but it won't get out of its own way and can't even get on plane. No major damage like chunks out of pump blades or impeller, but the impeller blade to pump housing clearance is beyond serviceable limit per manual (.036" shim fits loose in spots, service limit is .035"). My question is, what do you do about this? Best I can tell you can't shim the prop to adjust clearance, so am I stuck throwing parts at it? My plan is to pull pump case and measure ID at impeller location; if ID is beyond serviceable limit, replace the case, if its acceptable replace the impeller. Thoughts? Any other pro tips on pumps for these things? Any help appreciated. Thanks.
Have a 1976 JS400 and seem to be having caviation/pump issues. Got it running good but it won't get out of its own way and can't even get on plane. No major damage like chunks out of pump blades or impeller, but the impeller blade to pump housing clearance is beyond serviceable limit per manual (.036" shim fits loose in spots, service limit is .035"). My question is, what do you do about this? Best I can tell you can't shim the prop to adjust clearance, so am I stuck throwing parts at it? My plan is to pull pump case and measure ID at impeller location; if ID is beyond serviceable limit, replace the case, if its acceptable replace the impeller. Thoughts? Any other pro tips on pumps for these things? Any help appreciated. Thanks.