hard to start mercruiser

[XWIND11]

Hello All,

OK, this is whats happening I have a 1993 renker cuddy 21' mercruiser 4.3l with alpha one outdrive. When Im on the hose and muffs boat starts fine typical carb start three pumps of throttle turn key. but when im in the water the engine just turns over and over for about 6 trys holding the key about 8 sec a try. After about 6 trys then it sounds like it goint to start for another 6 trys then it starts up and runs fine until you cut it off again. any suggestions.....

P.s. I had trhe carb rebuilt about 2 months ago

 

[cc350]

Re: hard to start mercruiser

Try neutral to full throttle then back down to 1/4 throttle and start.

 

[rockyman]

Re: hard to start mercruiser

you may try pullimg the throttle out and then pumping one time to full throttle to set the choke.

 

[Bondo]

Re: hard to start mercruiser

typical carb start three pumps of throttle turn key.

Ayuh,... With the throttle Where, at the turn of the Key,..?? 1/2,..?? 3/4,..??

 

[XWIND11]

Re: hard to start mercruiser

I do try that and set the choke. I pump it three times then put the throttle handle straight up in nuetral same way I do on the hose. I also do the full throttle to 1/2 to 1/4 to set choke when this happens on the water and same thing happens im going to go out and try it today without wife cause she freaks when this happens even though I know its going to start.

 

[intrepidvoyager]

Re: hard to start mercruiser

ok .....out of water starts fine ...in water won't $%$#@% !!

well seems that there are only 4 things that are diff .... one is that prop is in the water so make sure there is not drag on the drive system somehow ....obviously you're not actually in gear ......you could try taking the prop off and try starting in water. ........ also check your battery condition and cables for corrosion. two is that the boat is at a different trim ...... trim the boat on the trailer the same as it sits in the water and see what happens ....could be a carb issue. three back pressure ......to overcome back pressure you gotta have good battery power ...... four maybe you have a leaking exhaust issue ....you put the boat in the water and water starts leaking from the exhaust system into the engine and it takes the engine a few turns to clear the water ......good luck !

 

[havasuboatman]

Re: hard to start mercruiser

5, maybe you are just pumping the throttle lever too many times.
Sounds to me like you are maybe flooding the engine a bit. You have a rebuilt carb. That means you have a nice strong accelerator pump.
When it does start, is ther a strong fuel smell? If so, there you go.
And before you ask me why it starts fine on the hose with 3 pumps, it's because your exhaust is full of water to the water line. It takes several revoultions just to clear that, meanwhile, you are drawing more fuel into the cylinders with each revolution.
Try starting with one pump.

 

[XWIND11]

Re: hard to start mercruiser

Cool,

I will try all suggestions tomm and get back.

Thank you

 

[intrepidvoyager]

Re: hard to start mercruiser

OK ...its a 93 Rinker ....some Rinkers sit real low in the water. if you have had the boat since new and never changed the riser ..... that's probably the issue ..... when the boat is on the trailer no problem ....in the water problem. Risers and some manifolds should be changed every 4 to 7 years ...4 in HI can toast them and maybe you'll get 7 plus if you are running in fresh water.

Cheers

 

[intrepidvoyager]

Re: hard to start mercruiser

forgot ...check your oil for any trace of water ...if not sure if its slightly discolored compare to fresh oil.

 

[Don S]

Re: hard to start mercruiser

OK ...its a 93 Rinker ....some Rinkers sit real low in the water. if you have had the boat since new and never changed the riser ..... that's probably the issue ..... when the boat is on the trailer no problem ....in the water problem. Risers and some manifolds should be changed every 4 to 7 years ...4 in HI can toast them and maybe you'll get 7 plus if you are running in fresh water.

Cheers

Huh ??????????

If the riser was the problem, it would be because water was getting into the cylinders, which would cause a hydrolock. The same thing would happen on the hose.

Xwind, you might also want to check your timing. It possible to have the timing so far off that it won't start in the water because of the back prressure on the exhaust system. But out of the water the engine "Sounds" like it's running fine, but really isn't.

 

[intrepidvoyager]

Re: hard to start mercruiser

You need a fair amount of water to cause hydrolock ...what i am talking about is a small leak in the engine side of the riser that does not clear due to substantial back pressure when a Rinker is dumped in the water, enough to momentarily ground plugs . Had exactly this stuation in a custom build. Depends on position of leak and how the boat sits in the water etc. In any event its good practice to check your oil before and after you go out.