2008 Tahoe Q5i 4.3 Mercruiser Engine

[Jmathis337]

So I bought a boat the owner said it had around 70 hours on it. I believe him it completely looks unmolested ect. It started in his driveway the day I looked at it no issues. I took it out on its maiden voyage and did some tubing. I shut the engine off multiple times that day but the last couple it dieseled. The engine however restarted two more times. Then it would start even with throttle set to WOT just would pop. So we got pulled back in. I trailed boat home the following day thinking I flooded the engine let it sit all day. Around 3pm I started boat it fired right up I let it run for 10 to 15 minutes idling. Even gave it a few revs and no issues turned motor off and then back on with no issues. The day after idling in driveway I took it to lake launched off trailer no start only popping ect had a couple fire balls when I had the air filter off. Took back home tried to start at home even used ether to try to start it. Then engine almost started but didn't I only sprayed like 3 shots down carb. Anyway what are your thoughts on what to do.

 

[Bondo]

Ayuh,.... Welcome Aboard,.... It ain't getting gasoline,....

 

[tpenfield]

A couple of pointers . . .

* 15 years and 70 hours is not a good mix. If the 70 hours are true, then the boat probably sat unused for extensive time periods

* Most folks sell nice looking boats for a reason

* Everything runs great in the driveway, but it means nothing.

I agree that it is probably a fuel problem, so you should go through the fuel system, run a heavy dose of fuel system cleaner, etc. Tell us a bit more about the engine (serial number would be good to have). Is it fuel injected or carbureted?

You should also check the ignition timing to make sure that is on spec.

 

[Jmathis337]

It is a carb tks fuel system. The reason they sold the boat is they are in their 60's and his wife had a real hard time getting in and out of the boat. I don't have the serial number on me to give. I told the old owner what happened and he was pretty messed up hearing that it wasn't running right. The dude took very good care of it. replace all kinds of things he is one of those ocd people. I even got 6 jugs of oil for the engine even. He had every manual for the boat all the way down to the stereo. The mechanic I took it too said possible ICM but he would make sure and that it would be cheaper just to upgrade to HEI.

 

[Jmathis337]

I thought fuel myself but I figure with ether it would have started I took the top part of the carb off and the had gas in it.

 

[tpenfield]

Cover the basics- timing, fuel, compression

 

[Jmathis337]

Yeah I sent it to mechanic to look at and check it hoping I walk away with only a 500 dollar bill lol.

 

[Jmathis337]

What is the solution if the ICM is in fact bad because you can't get them anymore

 

[nola mike]

What is the solution if the ICM is in fact bad because you can't get them anymore

eBay or conversion to Delco. But unlikely cause in your case. TB V (if that's what you have) is tough to find.

 

[Jmathis337]

Well the verdict came back and it was a bunch of corrosion on the rotor and cap due to condensation. Anyone know how to prevent that from happening?

 

[tpenfield]

Well the verdict came back and it was a bunch of corrosion on the rotor and cap due to condensation. Anyone know how to prevent that from happening?

Use the boat fairly often

 

[Jmathis337]

Yeah unlike it's old owner I will be on the lake often