August 12, 2020 at 9:47 am #211416
Hi all, two questions about starter motors. (1992 merccruiser I/o serial # d805173).
1, when getting new one the best way to figure out CW or CCW rotation ? Difficult to understand which part is the direction referring to and which side your looking at it .
2, lubrications. Do you grease, oil or nothing to the starter shaft—the shaft bunion turns on. Opinions seem to differ.
Canada Member - 2 Years
Topics: 432August 12, 2020 at 11:16 am #211420
I’m not positive but I believe Mercury views their motors from the rear instead of the front as is normally done. In other words, what the rest of the world would say is a CW rotating motor, Mercury would call it CCW rotation.
You’ll have to double check but I’m sure this was the issue I had a few years ago when I rebuilt twin 470’s and had to get the correct starters for them. Both motors ended up being standard rotation with one of the outdrives being reverse rotation.
August 12, 2020 at 12:04 pm #211422
- This reply was modified 1 month, 2 weeks ago by Mumbles.
Well I looked up the part number on marinengine.com using the mercruiser serial number, got starter 18-5911 Sierra…it says it’s cw rotation. I ordered few days ago and got part….but something in the back of my mind remembered cw or ccw rotation…started looking into it and got more confused and worried I got wrong part.
On the boat, looking aft to the pulley it turns cw , if I imagine myself at the back looking forward then it would spin ccw.
The starter sits low starboard side with the point/binion pointing aft.
I’ll take the old one out tomorrow and see but I think I screwed up and ordered wrong part..but marinengine.com part number was specific to my engine serial number…August 12, 2020 at 12:23 pm #211423
Looking at my Mercruiser shop manual for my 1996 4.3 Liter V6, They define engine rotation as looking at the engine from the stern end – that’s where the outdrive hooks to the flywheel, and the rotation of the V6 engine is counter-clockwise, as probably is all the other engines they use.
I also have the shop manual for the outdrive , and it shows reversing rotation is done by the the outdrive, so it doesn’t affect the starter or the engine. Note that the engine and the outdrive have separate serial numbers.
For starter Lubrication, you didn’t say which engine you have, but if it’s based on a general motors engine like my 4.3 liter is, it’s probably the same. My shop manual says that if you disassemble the starter, internal bearings and internal gear teeth (yes there are some gears inside you can’t see) should be lubricated with Quicksilver 2-4-C Marine Lubricant. There is no required maintenance regarding this, so unless you have disassembled the starter, don’t worry about it. It’s like a car starter and you don’t periodically lube them. The shaft end that sticks out has the “Starter Drive” on it.. This is the gear that rises up to engage the flywheel and there is a ratcheting mechanism right behind that gear that is part of the starter drive assembly. If your starter spins but doesn’t turn the engine, the ratchet is shot (a common failure) so that starter drive assembly is all you need to replace – take the old one, or your whole starter to any auto parts store and they will have it, and it will look similar to the one in the link below: The manual says to lubricate the starter shaft that this slides on with 10W oil when you put on a new starter drive. My personal experience with cars is lube that shaft very sparingly because excess oil attracts dirt and that will cause problems.
If you have a MerCruiser with a Ford-based engine, recommended lubrication may be different, but I don’t think Mercury has used Ford-based engines since the 1970s.
link to Typical starter drive below.
August 12, 2020 at 12:29 pm #211425
- This reply was modified 1 month, 2 weeks ago by outbdnut2.
I looked up the Sierra starter you bought and yes – it’s definitely a GM starter, so the stuff I just posted applies.
DaveAugust 12, 2020 at 12:43 pm #211427
Thanks Dave. I just found this post with pictures…it helps… I think I got the right starter.August 12, 2020 at 1:15 pm #211434
Thanks Dave. I just found this post with pictures…it helps… I think I got the right starter.
Interesting. It does say “Inboard engines” onthe diagram you found, which makes sense that there would be reverse rotation engines for dual prop setups on inboards with shaft-driven props under the boat, not on an outdrive. Now maybe some V8 Merc I’Os do have reverse rotating engines, but with the V6 I have with the Alpha One outdrive, the shop manuals say reverse rotation is done in the outdrive.
DaveAugust 12, 2020 at 3:15 pm #211442
i used picture to follow the rotations: the starter rotates clockwise (CW)-looking head onto binion. since it faces aft, will turn flywheel CCW which in turn will turn pulley CW when facing it from the front looking aft. And that is the correct direction. you follow? at least i think i follow…ill see tomorrow.August 12, 2020 at 3:21 pm #211444
i used picture to follow the rotations: the starter rotates clockwise (CW)-looking head onto binion. since it faces aft, will turn flywheel CCW which in turn will turn pulley CW when facing it from the front looking aft. And that is the correct direction. you follow? at least i think i follow…ill see tomorrow.
It sounds like you have a good handle on it now! Hope the starter cures your problem! Just curious as to what engine you have? HP? V8?
DaveAugust 12, 2020 at 4:37 pm #211453
ya i’ll see who has a handle on who… also not looking forward to taking it off and putting new one on…heavy and in tight position..we’ll see…it almost left me stranded on the lake …starter spinning but not engaging…a couple of whacks on it got it to engage and started to go home.
I used that picture to only figure out if it is the right starter turning engine in the correct direction…not think about the outdrive that you were talking about.
its a 1992 mercruiser alpha one 3.0L, serial # d805173. not sure but i think 150hp.
US Member - 2 Years
Topics: 41August 12, 2020 at 4:48 pm #211454
Starters are confusing. They should name them the same rotation as the engine they go on, but I don’t believe that is the case. All 3.0 liter Marine GM ENGINES are left had rotation. Marine nomenclature views the engine from the stern looking forward. To be sure you have the right starter, look at the teeth. You will see the end of the gear teeth have tapered edges. If your new starter has the same taper as the old one, then the rotation is correct. If the taper is on the opposite side of the teeth, then you have the wrong rotation starter.
Long live American manufacturing!August 12, 2020 at 4:58 pm #211455
I used to have a mid 1970s 3 liter. The 3 liter is the basic 4 cyl Chevrolet engine that was the base engine in the first Chevy II’s (later called Novas), but gas was cheap then so nobody bought the 4 in the Nova. That base engine, bought from GM and built up by Mercury for marine use, has been a very reliable, long life marine engine for many years. The ones I’ve seen are 120, 130 , and 140 HP models. Mine was 140 HP. Bought the boat used in 1984 and ran the hell out of it every summer at dad’s lake cabin until 1999.
US Member - 2 Years
Topics: 15August 12, 2020 at 5:19 pm #211456
another thing if it mounts from the front or rear. make a difference.
US Member - 2 Years
Topics: 41August 13, 2020 at 5:54 am #211494
By the way, as for lubrication, I have always put a VERY THIN amount of light weight grease on the shaft. Usually I am replacing a starter that was a big ball of rust; so I tend towards putting SOMETHING on the shaft, even though nothing is really specified. I’ve been doing it for a lot of years an there haven’t been any problems from it, that I know of.
As you might guess, the trick to keeping the starter working is to check the operation of your automatic bilge pump, all the time. If you don’t have one, install one. And don’t launch the boat with the plug out. Ha ha, I know, but it happens. All it takes is for water to get as high as the lower teeth of the flywheel one time, and then the count down to starter failure starts. I know that Mercruisers have a supposedly sealed flywheel housing but this is sketchy.
Long live American manufacturing!
- You must be logged in to reply to this topic.