View Full Version : Kudos to Indmar Engine Nut?

08-16-2010, 12:11 PM
For all those that have the cat 340 engine, I just talked with Larry at Indmar about a engine temp problem I have been experiencing. Occasionally at idle my temp would spike up to 170, 180 and this past weekend 203 setting an engine fault code. I check my screens Water filter, and trans cooler all were clear. check my impeller previous and was fine , but decided to replace it ...the one i pulled out looked brand new but replaced anyways...(took 30 mins on my v drive silicone lube and large needle nose vise gips and back panel remover for easier access.
Anyways Larry explained that at lower rpm with the cat running so hot that the water vapourizes to steam in the jacket and enters the top of the water distribution and then the J tube gets sucked shut from the water pump sucking causing a popping sound of the tube compressing and expanding. Giving a little throttle in gear or neutral will increase impeller flow to cool the cat and stop steam.......an fyi for cat owners and thanks for the explanation.

08-16-2010, 01:09 PM
good info. thanks for the advice. have not noticed that issue, but I very rarely idle the boat. when swapping riders, it's an immediate shutoff to save hours..

08-16-2010, 08:10 PM
Good to know considering the CAT 340 engine is supposed to be the new stock engine for Moomba