merc 4.5hp

E120B · Sep 15, 2004

hey i got a old merc 4.5hp and it's been sitting a while.. im trying to get it going. but the pull start is on the engine cover!! how do i pull it over to check spark?? the serial # is 4599632 and it is a mercury 4.5hp longshaft any help is help full!

Merc805 · Sep 15, 2004

Re: merc 4.5hp

And.. You don't have the engine cover ? Don't quite understand. You can use a cord and wrap it around the flywheel.

E120B · Sep 15, 2004

Re: merc 4.5hp

i have the cover but when i put it on i can't see the motor... and there is no spot to wrap a rope around it..

Merc805 · Sep 15, 2004

Re: merc 4.5hp

I see what you mean.. This is a 1980 4.5 and when the cover is off..

I would start it with the cover on.. let it warm up.. then use a 14v cordless drill on the centre nut (one with a clutch to avoid broken wrist) a warm motor will kick over real easy. Suppose a push start would be difficult..

E120B · Sep 16, 2004

Re: merc 4.5hp

could i just use the drill to check spark?

Merc805 · Sep 16, 2004

Re: merc 4.5hp

Take out both plugs to eliminate compression and it should work. You need to take them out to check spark anyway.

E120B · Sep 16, 2004

Re: merc 4.5hp

it's only a single cylinder 4.5 hp how do i get the lower unit off... i took the one bolt out but it doesn't want to fall.. i have a seloc manual but it don't help very much

Merc805 · Sep 16, 2004

Re: merc 4.5hp

There will be more than 1 bolt. Have a look here http://www.dougrussell.com/partscatalog/collections/index.cfm?fuseaction=collectdetails&colid=01 You will find detailed diagrams. After you get the 2 or 3 bolts out, you will need to use a rubber mallet or a hammer and block of softwood the whack the L/U off. It should have a S.Steel driveshaft and should eventually fall. Replace the impeller as a minimum requirement since you have the L.U off. The drill and large socket should work with the plug out, the hard part will be finding a suitable drive 1/2" for the socket to the drill. You may have to make one.

dajohnson53 · Sep 17, 2004

Re: merc 4.5hp

Referring to photo posted by outbored: I think you could "rope start" it with the cover off. Use a broad strap instead of a rope - like a leather belt or broad nylon strap. If you wrap the strap around itself a couple of times, there will be enough friction to turn the engine, I'd wager. I started a snowmobile out in the middle of nowhere way back when with my belt, using this technique. Similar situation - no "notch" for a rope start. Give it a try and let us know.

accord_guy · Sep 17, 2004

Re: merc 4.5hp

I have this same engine. You have to get it started and carefully remove the cover. It's near impossible to start with a rope or strap due to the tight clearance around the flywheel. Hint: You can use a harmonic balancer puller to pull the flywheel. ($10 @ Pepboys). A tip for removing the cover is to slowly lift while moving the cover forward. I've been restoring a 1977 4.5 for about a month. It was a kicker motor for 10 years (barely used). Then it hung on a stand for the following 17 years in a barn. The wasp had made mud nests thru-out the engine compartment and eaten the wiring. I have about $200 in it. Check the wiring for the kill switch if no spark. This is a great little motor and well worth the restore. If you can't get it running, piece it out on e-bay. The lower unit parts aren't available anymore and go for big bucks.

E120B · Sep 20, 2004

Re: merc 4.5hp

well the i got it fired up. it doesnt seems to be pumping water but i blew out the tell-tale stream and it pumped for a few seconds, than stopped. how hot should this lil 4.5 get? it's getting hotter than my 50hp merc

Merc805 · Sep 20, 2004

Re: merc 4.5hp

Don't run it without a water flow, or it will get very hot.. then stop.. permanently. What technique did you use for the pull start.

E120B · Sep 20, 2004

Re: merc 4.5hp

once it was warn i could spin it with a clutched drill and it would start. it's not getting hot. it just a little bit warmer than i like. (I worked at a evinrude dealer for 8 weeks) im guna try cleaning the tell tale out. should water come from the exaust on this motor? some rude's it does and others it don't

E120B · Sep 20, 2004

Re: merc 4.5hp

also is there a thermastat on this motor if so were is it. my seloc manual doesn't cover this motor very well

E120B · Sep 21, 2004

Re: merc 4.5hp

there's only 2 bolts in the lower unit right?

merc 4.5hp

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