Mercruiser 130hp will not idle when cold and other bits...

[donie]

Hi all<br /><br />I've had this problem since I got my boat where it just will not idle when cold. I have to leave it running at 1500 for a while to heat it up and then whack it into reverse to get it out of the slipway. Once she's moving she's fine and when she heats up she's perfect. No hassles for the rest of the day... (almost)<br /><br />When I try to take off when out of the speed limit area I just try to power up and she immediately start to die. I throttle back and stabilise and do it again. She goes. This ALWAYS happens but only ever on first power up.<br /><br />The other small problem is the engine keeps firing after being switched off but I guess this is due to carbon build up as I'm in Ireland and we get crap grade unleaded petrol. I'm gonna run some redex through it to clean it. I guess that will solve this problem. Does anybody know of any product that I can use on a permanent basis to keep the engine clean?<br /><br />I've done a few things to solve the problem and one was to strip the carb down to clean it. There was no noticeable muck in there so I just blew out the jets and stuff. Put it back together and she was more or less the same. I still have to tune it though as my idle mix might be off as it was late when we started. But I had done this before and it didn't help.<br /><br />New plugs so it shouldn't be a plug problem. Runs fine all day and is a sweet enough engine. It's a 2000 model.<br /><br />One other issue I've had sine the end of season is that I topped up the transmission reservoir and it was fine at the end of the season last October. I've noticed that it's completely empty now. Oil is in the bilge though so I guess it must be the oil line is the problem as it goes into the outdrive through the transom. If it was leaking in the gearbox I guess it would leak into the water? Could this be a gearbox problem? However, it looked like there had been a leak as the alternator looks like some oil dropped on it but the reservoir looks OK and line connections are tight. Need more investigation but if somebody could tell me if this is serious or not I'd be grateful and maybe what I could check to eliminate some things?<br /><br />Thanks for any help.<br />Regards<br />Donie

 

[Ryoken]

Re: Mercruiser 130hp will not idle when cold and other bits...

sounds like a choke issue... <br /><br />more specifacs on the boat? what motor and carb setup?

 

[donie]

Re: Mercruiser 130hp will not idle when cold and other bits...

The boat is a Maxum 1800 SR and the carb is a 2BBL on a 135hp 3.0ltr. Outdrive is Alpha 1<br /><br />Year 2000 Model boat and engine and outdrive.<br /><br />Thanks<br />Donie

 

[mercrewser]

Re: Mercruiser 130hp will not idle when cold and other bits...

Gear oil is probably coming from upper seals, thru the bellows and into the boat. Pull the drive to see if bellows are full of oil. As for engine, did you shoot the timing light on it?

 

[airman]

Re: Mercruiser 130hp will not idle when cold and other bits...

Your starting problem sounds like choke to me, too. The run-on can probably be solved by allowing the engine to idle for a minute or so and running the blowers before shutting it off. You are trying to cool the engine before shutdown and this is a common problem on boats with tight engine boxes. The throttling up problem is likely either a weak shot from the accelerator pump or a slightly weak spark. A small amount of oil usage is normal for the drive but it sounds like you have a static leak. Pull the drain plug on the drive to make sure the oil isn't getting milky - it should be changed anyways. If there's lots of oil in the drive and it's clean then don't worry. Pull the drive off too and grease the splined shaft - it's really an easy job and the gaskets are about $5. Take a really good look at all the bellows, too. They aren't as cheap or easy to replace but after 3 years they're likely due and its way cheaper to replace them before they leak. Have fun and keep posting.

 

[donie]

Re: Mercruiser 130hp will not idle when cold and other bits...

Hi<br /><br />Carb Q: Does the idle mix only affect the mixture when the engine is idling? I'm wary of moving it but I think I need to adjust this as the running is quite rough when idling normally at the moment.<br /><br />Other other quick thing. It says in the manual to set the idel speed to 750ish rpm when the boat is in gear and not powered up. What RPM should I expect the engine to be at when it's taken out of gear? I guess it goes up to 1000 or so?<br /><br />I'm not qualified to do this stuff but I'm pretty handy. <br /><br />Thanks<br />Donie

 

[rattana]

Re: Mercruiser 130hp will not idle when cold and other bits...

Yes the idle mixture only affects the idle circuit. The other circuits (high speed circuit, etc) are metered by jets, and aren't affected. You can use a tachometer to adjust the idle mixture. Make sure the engine is warmed up fully. In neutral, adjust the idle mixture screws for the highest idle. Start at 1 1/2 turns from lightly seated. On a 2 barrel, both screws should be turned out roughly the same amount. Adjust out slowly alternating between the two. If you turn out too far and the idle starts to drop, turn back in again. Once you have reached the best smooth idle, you have to turn the idle screws back in to drop the idle approximately 100RPM. This is called lean drop. This will prevent the mixture from being too rich and fouling your plugs. Don't make it too lean, but 100 RPM drop is no problem. That may help your runon problem. Also, I think 1000RPM in neutral is a little high and maybe that is why it is hard to get into gear. I try to idle at 750RPM in neutral on my engine.

 

[donie]

Re: Mercruiser 130hp will not idle when cold and other bits...

Hi rattana <br /><br />What I'm wondering is though is what the idle speed in gear is becasue that's the way to set the idle speed I think. I can do this no problem when I get around to it but what I'm wondering is; will the engine idle at a higher rev when it's out of gear?<br /><br />Thanks for all the help<br />Donie

 

[rattana]

Re: Mercruiser 130hp will not idle when cold and other bits...

Hi Donie<br />It will idle higher out of gear. In gear there is the load of prop turning in the water trying to push the boat.