Fuel issue indmar 325

[ktrojcak1]

Got it fixed
One of the fittings on the water filter was just loose enough to let the impeller suck in some air with the water
I took off the intake line to inspect and tried to blow through it an some air came out around the fitting tightened it with Teflon and boat runs flawlessly now thanks for all the help and suggestions

[SupraDs]

Can someone explain ktrojcak1’s fix? I don’t see how letting some air in the water system would produce the rough engine performance? Especially if the water temperature gauge isn’t showing an anomaly.

I’ve been trouble shooting the same issue: after 30 minutes of wakeboarding, the boat backfires and stumbles... I’ve been focusing on electrical gremlins (suspecting that increasing heat is causing increasing resistance) and fuel delivery problems (BUT I get a solid 30 PSI even when it backfires).
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2001 Supra Launch v-drive with Indmar Assault

[tretter7]

Can someone explain ktrojcak1’s fix? I don’t see how letting some air in the water system would produce the rough engine performance? Especially if the water temperature gauge isn’t showing an anomaly.
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Have you ever tried to drink from a straw that's got a crack in it, and all you get is bubbles along with half the Coke you expected? Same thing. Easiest way to check if a temp issue could be causing this (and your gauge isn't picking it up) is to to the 5 gal bucket water flow test and make sure you have proper flow.