Need help with runability problem

[WICKED FX4]

I have a 2005 bayliner 185 with a merc 4.3l and alpha one drive. I recently replaced the engine in my boat due to previous owner not winterizing and cracking the block. I just took it out today for the first time since putting the new engine in and it doesnt go above 1800 rpms. any help would be much app.

 

[gcboat]

Re: Need help with runability problem

The first thing I would look at would be your throttle linkage. Could be that something got a little out of whack on the install. Also go with a complete check of your timing. Fuel starvation, crimped lines - could be anything.
Just backtrack your moves and see if there might of been something you missed. Just a thought.

 

[WICKED FX4]

Re: Need help with runability problem

thanks, let me tell you what i have. installed new fuel filter, lines are not pinched, i have set timing per service manual and have used service manual to make sure all wiring is in proper place. i have gone by the service manual on everything during the install and checked and double checked everything.
Personally it is acting like the timing is off or the choke on the carb is stuck closed. any other suggestions on where else to check would be great. And throttle linkage is great goes smooth all the way to wot.

 

[Don S]

Re: Need help with runability problem

There are a lot oif things that could cause low WOT (Wide Open Throttle) rpms. Especially after a lot of rework.
Have a look at this.
http://forums.iboats.com/showthread.php?t=295070

 

[chiefalen]

Re: Need help with runability problem

You installed the heads ? How did you go about tightening the rockers ?

They to tight ?

I have to believe you followed the manual for everything , but what method for the rockers ?

 

[Bondo]

Re: Need help with runability problem

I recently replaced the engine in my boat due to previous owner not winterizing and cracking the block.

Ayuh,... Is this New motor a Known commodity, or a Shot in the Dark,..??

New,..??
Rebuilt,..?? By whom,..??
Used,..?? any History,..??

 

[Don S]

Re: Need help with runability problem

Surprisingly, I have had customers bring in boats that won't get proper rpm and tell me that it idles fine. Only when I start it up, my ear hears a different story. Compression check shows 1 or 2 cylinders with no compression, or spark plugs not firing, bad wires, vacuum leak, who knows. You have to check the basics, guesses won't help a bit in finding the problem

 

[Silvertip]

Re: Need help with runability problem

You can look at the carb and tell whether the choke is stuck shut! And if it was it would be gagging, wretching, shaking, and belching black smoke. All pretty obvious.

 

[Lone Duck]

Re: Need help with runability problem

Surprisingly, I have had customers bring in boats that won't get proper rpm and tell me that it idles fine. Only when I start it up, my ear hears a different story. Compression check shows 1 or 2 cylinders with no compression, or spark plugs not firing, bad wires, vacuum leak, who knows. You have to check the basics, guesses won't help a bit in finding the problem

Yeh! I've had people tell me their chain saw runs great but it just won't start.

 

[WICKED FX4]

Re: Need help with runability problem

I got the motor from Raul at Rapido Marine and it was just the short block used the same heads from the old motor after having them check for cracks and surface at a machine shop. The rocker arms use hydralic valve adjusters so there is no adjustment as far as valve lash. I am a mechanic so yes i followed the service manual and torqued everything to specs. And i never said that it idled good and it doesnt have a misfire.

 

[Don S]

Re: Need help with runability problem

I got the motor from Raul at Rapido Marine

He has had problems with a couple of his engines on this forum, and seems back up his product. Have you contacted Rapido yet. ???? Seems to me that should have been your first step.