straight 4 mercruiser questions

[nick.wright]

Bought a boat with a straight 4 mercruiser and have a few questions. First off, when I change the oil, do I let it run into the bilge and out the drain hole? What weight oil should I replace it with? Can I pick up a filter down and Advance Auto (is there an auto filter that will work)? I also think my plugs wires might be crossed (engine spits a little with starting fluid, but never actually runs) Can anyone tell me what the cylinder order is from the front to rear? First of many questions.....

 

[Don S]

Re: straight 4 mercruiser questions

The answer is NO to draining it into the bilge.<br /><br />Mercruiser has been using 4 cylinder engines since 1965, care to tell us what model you have there, Year and model number would be handy.

 

[nick.wright]

Re: straight 4 mercruiser questions

Well, I'm new to boats. The boat is a '79, so I'm guessing the engine is from the same time period. I'll look tomorrow and get the pertinate info from the engine. HOW DO I DRAIN THE OIL????

 

[Laddies]

Re: straight 4 mercruiser questions

Get a pump and pump it out the dipstick, once it's dry you can purchase a kit that attaches a hose on the drain plug to reach the rear drain plug to drain the oil in the future. If you drain in the bilge you will have a mess that lasts forever

 

[nick.wright]

Re: straight 4 mercruiser questions

Thanks Laddies. Don't want more of a mess than I already have. As for more engine info, I can't seem to find any more on the engine itself. The Mercruiser decal is partially missing. If it helps, it has a Mercruiser 120/140 outdrive attached.

 

[DHPMARINE]

Re: straight 4 mercruiser questions

Even a Clymer manual will help you out,and I feel you really need one.Firing order is 1-3-4-2,but now you'll need the distibutor rotation.And the wire locations.<br /><br />There should be a fitting on the oil dip stick that looks like what your garden hose screws onto.This is where the pump attaches.But I reccommend warming the engine up first,which means you need to get her running.<br /><br />So I think you need amanual.<br /><br />DHP

 

[nick.wright]

Re: straight 4 mercruiser questions

any chance that chevy might have made this engine for mercruiser? If so, I have a couple of chevy s-10 manuals from 1980 that depict the 2.5 and 3.0 engines.

 

[Don S]

Re: straight 4 mercruiser questions

With the 120/140 drive, your engine should be the GM 4 cylinder engine. Now, to determine if it's a 2.5 or a 3.0L is going to be the question.<br />Here is a service bulletin from Mercruiser that should help you determine what engine it is.<br /> http://www.boatfix.com/merc/Bullet/97/97_06.pdf <br /><br />Also, if you're lucky, look back by the starter, there MAY still be a metal tag with the Mercruiser Serial number on it. That will tell the story.<br />Since the engine won't start, (BTW, loose the starting fluid before you destroy your engine) I would sure check for spark and good gas. Possibly hook up an outboard gas tank to the fuel pump instead of the boats tank till you get it running.<br />Also, do a full tuneup. Points on boats don't last as long as they do on cars. Do you get gas out of the accelerator pump? <br />Do you have ANY kind of a manual to help you with troubleshooting and the tuneup?<br />How much do you know about engines?<br /><br />Just noticed your previous post. NO, the S10 did not have the same engine. Besides that, you need a marine manual. Lots of different things on marine engines than automotive engines.

 

[DHPMARINE]

Re: straight 4 mercruiser questions

Compare your manuals to what you have <br /><br />It's a GM block .... Doubt the S10 used it.<br /><br />DHP

 

[nick.wright]

Re: straight 4 mercruiser questions

No marine manual yet. Where can I get one from? Engine does have spark at the points, not too sure yet how bad the plugs and wires are. That is my before church project tomorrow am. Cap and rotor look almost new from the inside. No corosion, cracks, or moisture. I've already chunked the starting fluid. There is a circut breaker mounted to the engine. The leads were loose this am. After tightening, the engine is now "trying". Also, where can I find a pump to suck the oil out of the dipstick?

 

[whywhyzed]

Re: straight 4 mercruiser questions

there's a link at the top of this page -below the "file folder tab" links where it says "manuals". Click it.<br />S10 engine totally different. 1964 ChevyII more like it. Marine manual more like it.<br />Clean and gap the points. Check compression.

 

[Bondo]

Re: straight 4 mercruiser questions

If the motor has a Harmonic Balancer on the front of the crankshaft,......<br />It's a 3.0l.........<br /><br />If there's No harmonic Balancer,......Just a pulley,...<br />It's a 2.5l........