Breaking in a 657x. Starts easily, but after the 30 minute runs starts w/ difficulty

[FPDeck]

I had a new 657x engine installed in a '95 Sportster. I'm new to PWCs (have always been an outdrive guy), so these engines are an anomaly to me. Anyway. I have the extra oil mixed into the gas for the 10 gallon break-in period and here is my problem: When the engine is cold, it always starts quickly. But after I do my 30 minute run and then the prescribed 30 min cool-down period, it is a big challenge to get it restarted. Acts flooded or something like that. By the way, I am cleaning the plugs between these break-in periods. I've done a total of 90 minutes of break-in running so far. Will this problem go away when I go back to having only the oil injector do its job without the added oil to the tank? Thanks. also, am I supposed to be cutting off the fuel supply switch when not using the boat (i.e. brief times of storage or trailiering?) THANKS!

[mtuned]

Re: Breaking in a 657x. Starts easily, but after the 30 minute runs starts w/ diffic

Whats your compression?

[dsolie]

Re: Breaking in a 657x. Starts easily, but after the 30 minute runs starts w/ diffic

Yes, you should turn off the fuel when the boat is not in use.

As far as the hard starting, can be caused by a few things. One would be excessive rotary surface clearance, the other would be a bad vent in the fuel (tank) system. Next time it does it, open the gas cap, and see if there is a pressure relief... If there is, you have a problem with a vent.

[easttenneski]

Re: Breaking in a 657x. Starts easily, but after the 30 minute runs starts w/ diffic

The vent is an issue a lot of times overlooked, been trying to figure mine out, bogged and similar starting issues, today when it was sitting on the trailer took the gas cap off and it launched about 5 feet over my head, that tells me there is something up with my vent system, so i imagine i am pulling a good vacuum on it while running, check that first its an easy check

[hpseadoo]

Re: Breaking in a 657x. Starts easily, but after the 30 minute runs starts w/ diffic

I have been having similar issues with a different boat and motor. Is there a strarting point for checking the venting?