97 3.0lx Mercruiser

[heyttown]

Had the boat in the mechanic for a carb rebuild and general check up to help solve a hard starting, and dieseling problem... Mechanic found engine 11 degrees off and reset timing and did carb rebuild. Took boat out and it had some problems at idle wanting to surge and after I shut it down after a 15 minute run to fish it didnt want to start.... So took it back to him, and he says he did some tuning on the carb? and found the timing off again, and asked me several times if I had messed with it which I hadnt. So he adjust timing and took it out on test run said it was all back to normal. I pick boat up and topped off the tank. Boat started great, got up to temp at dock...Backed out of slip and it stalled, hard to start again...I did finally get it started and proceeded to head out..

Ran into a stranded boat in the channel so I towed them to safer water as their buddy was already on his way out to help, and my boat stalls again, now its really hard to start, I tried pumping throttle(neutral) to give a few squirts of gas and finally have to peg the throttle and it fires up... I cruise around just burning up some gas,various speeds and throttle on plane off plane...no problems...I head into the ramp, slow down get off plane,idle in and it dies...and no matter what I do it will not start...Luckily the wind blew me towards the dock..

My question is, short of the mechanic not tightening the distributer nut down tight, what would cause the timing to be off again... And im assuming a 3rd time as its doing the exact same thing today when I was out.

Im starting to get discouraged about this boat and my mechanic.

Any ideas?

 

[Don S]

Re: 97 3.0lx Mercruiser

IF the timing is off again, I would be looking at the roll pin holding the gear on the distributor shaft. If it's sheared, the broken pin may be binding enought to allow it to run for a while before finally moving enough to not idle.

 

[heyttown]

Re: 97 3.0lx Mercruiser

Sorry for the long delay in response...The mechanic finally fixed the timing issue and said the bolt on the dist. wasnt getting tightened enough...So after 2 trips out the timing issue has been resolved.

I still however have the hard to restart issue. With the motor cold,it starts up better then it ever has since Ive owned it...Problem is after engine gets up to temp 165-170, if I shut it down its very very hard and sometimes wont even start. Lots of cranking over various # of throttle pumps to inject some gas to even holding throttle wide open until it finally catches and starts running.
A few yrs ago we found a crack in the block from improper winterization, There never has been water in the oil,both when we found the crack and every oil change since then, that cracked was repaired with JB weld(dont kill me please,its worked great for 3 seasons now)

The mechanic suggest taking the head off and having that checked, but as many times as I had to take boat back to him for a loose distributer bolt, and just the way he talks leads me to believe he is just guessing and drawing straws right now..

Is there anything I can check myself that would help explain a hard to start after my engine warms up. Pulling the head just seems like to big of a jump and im missing(hoping) its something alot simpler then a cracked head.
Thanks for your time.

 

[Maclin]

Re: 97 3.0lx Mercruiser

Pumping the throttle is probably just loading it up with fuel and flooding it some, then holding the throttle wide open clears the flooded condition and it catches. I would try just opening the throttle 1/4 to 1/3 open next time and crank for up to 10 seconds and see if it can start that way. After that first try I would then open the throttle up to near full open and try for another 10 seconds, be ready to throttle down. The carb may be flooding slightly when sitting, pumping it won't help in a flooding condition but open throttle will. Just something to try next time.

 

[heyttown]

Re: 97 3.0lx Mercruiser

Thanks for the reply. I have tried every throttle position on a restart and nothing has seemed to work better then the rest.Im sure I have flooded it in the past. Keep in mind that the boat could sit turned off for as little as 1-2 minutes after a run, and is hard if not impossible to start.

I think he did a good job on the carb rebuild as once its running I have no problems at all,no hesitation and no bogging down at any speed. The mechanic was unsure of the problem at hand and to try and eliminate any guess on my carb being rebuilt wrong, he installed one of his carbs that he had...I took it for a test drive and had the same issues(hard to restart) with his carb.

I will say it seems to consume more gas then what I remember, we used to ski and tube with it for hours a day and go about 3 days before having to fill up...I just burned about 5 gallons in less then an hour of various speeds from idle to WOT. It could be that Im just looking so hard to try and find out whats wrong and the gas consumption is the same it used to be, but right now any and all info I can give to this forum the more informed help I get back.

Thanks again

 

[heyttown]

Re: 97 3.0lx Mercruiser

Anybody have any more ideas? I hope because Im at a loss and boating season is fast coming to an end this season.

 

[achris]

Re: 97 3.0lx Mercruiser

A long shot.... Check the exhaust manifold and elbow... If you have freeze damage on the engine block you could also have it in the manifold or elbow... If water is getting into the cylinder/s after you shutdown, then that could explain the hard starts....

Chris.........