150hp starting problems

[steve bain]

hey guys,

bit of a newbie question i'm afraid. its my first boat and as of yet i have been able to get her running consistantly.

I have a 150hp Mariner from early 90's. same as this one with oil injection. http://www.jeffsoutboards.com/Apr ... Mariner.JPG

anyway, its having trouble starting. i drained the carbs, new fuel, new fuel lines, new bulb, cleaned spark plugs and primed the bulb nice and hard. throttle at max (not engaged), choke (push in key type), and start. it cranks and cranks and cranks. eventually it started and i took the opportunity to spray in some 'power tune' all was good and i thought it was fixed. it starts fine. went to use it this weekend and back to square one again. couldn't get the thing started. it seems once it gets going its fine and sounds smooth, but it hates cold start. what may be the problem? or is it my start up procedure?
often it starts and runs far a few seconds and dies again

prior to this it has stood for the winter.

any advice or ideas appreciated on how i may be able to sort this out. i am going to check the compression this weekend.

thanks in advance. sorry about the newb question. steve

 

[borderboat]

Re: 150hp starting problems

Me x2 on this one, except mine is a 115. Took it out on the lake yesterday, after finally getting in started after launching and went to a fishing spot. Half an hour later I wanted to try a different spot and no go. Wound up flooding the darn thing & had to take out the plugs on the water, #2 & 4 were very wet. Let me know if you find a solution.

 

[j_martin]

Re: 150hp starting problems

The link is obsolete. It would really help if you just told us what your motor is, ie carb'd V6, XR4, etc.

I'll assume it is a carb'd V6 as this is the most common 150 hp from that time. In that case, be sure the enricher valve is working properly. It is operated by pressing in the key switch.

The enricher valve drains some fuel from the top carb to ports behind the valve plates, all 3 when cranking, just the bottom 2 when not cranking.

My song and dance, which results in life in about 3 seconds.
1. Pump primer till firm
2. Be sure engine is level, not too low (buried exhaust) and not too high (carbs too far off level)
3. Turn key on, and press enricher valve for 5-10 seconds, depending on weather.
4. Raise idle lever about half way.
5. While pressing key (enricher) crank to start.
6. If weather is cold, baby it with enricher for a few seconds.

hope it helps
John

 

[steve bain]

Re: 150hp starting problems

it lives!!

heres the advice i was given and thanks for your advice jmartin also. it was indeed a v6 carb.

'To overcome your problem, pump the bulb until hard, with the engine all the way down, press the choke button for 5 seconds. Squeeze the bulb until hard again and wait a few minutes. Move the throttle to the neutral start postion which should be just barely cracked. Trim the motor up level and crank the engine until it tries to fire, press the choke for two seconds and crank again. Repeat the two second choke sequence until it runs. It may smoke a bit when it starts but it should clear fairly quickly.'

once it started i then pushed the key in ad more choke again to keep it going. very pleased! it was the waiting a few minutes bit that made the difference as it gave the fuel time to get to where it should be

'The enrichner is just a solenoid valve that opens when you push in the key switch. It gets it's fuel from #1 carb set and delivers it behind the butterflys on carb sets 2 and 3. #1 set never gets choke fuel but can be drained by the choking process.

If the engine is older and the leakdown is not up to snuff the crankcases tend to dry out. The oil stays but the fuel is gone which is why they smoke after a cold start.

The fuel from choking has to get past the reeds and into the crankcase pretty much via gravity. This is why I learned the trick about re-squeezing the bulb and letting it sit a few minutes. Because of the extra oil in the crankcase you have to be careful about additional choking because it will be oil rich and that makes for a lot of cranking.'