Distributor placement, drop - Maxum Boat Owners Club

oneradride · 09-13-2011, 10:37 PM

Are boats designed to be 180 out? Unless I'm on crack I have always gone to TDC on #1 and the rotor points to number one...... the new cap I just bought is 180 off from that, point past the starter?
This pic sucks but ONE is right of the wires that are showing? I just want to make sure I have this dropped in correctly. Any help would be awesome.

tjwieseler · 09-14-2011, 01:21 AM

Don't feel too bad, I don't care how hard I try, I am always 180deg off. Nothing bad happens, just a little back firing, then turn it 180 deg, and all is good.

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mcoffey · 09-14-2011, 01:22 AM

That looks right to me based on this diagram from the Mercruiser Manual (#17).

oneradride · 09-14-2011, 01:31 AM

Awesome diagram THANKS! I'll turn it 180

mcoffey · 09-14-2011, 02:49 AM

Hold on now, I think you are good. The diagram shows #1 on the cap at the 5 o'clock position if looking from the rear (where the distributor is). Looking at your pic it seems to be right there right next to the blue butt splices (and right at the engine stand mount which is rear). So it seems like 5 o'clock there too unless I am looking at something backwards here

ss3964spd · 09-14-2011, 01:39 PM

But don't forget that there are two TDC's at #1. In other words, you can have #1 at TDC, but NOT on it's compression stroke. If #1 isn't on the compression stroke the dist rotor will actually be pointing 180 out - which I think is #6 on the cap. Remember the cam rotates only 1/2 a turn to each full turn of the crank.

Are you pre-priming that thing before installing it a lighting it off?

Dan

oneradride · 09-14-2011, 08:37 PM

http://www.youtube.com/watch?v=YdIGZ-tVuZA

@ about 2:05 in this video is my concern.

UNDER the cap.. the rotor is pointing at number ONE, because that's were I put it...... The cap on the other hand SAYS 6 (where the rotor is now, pointing at the number one cylinder under it).

It's just a GM 350... wondering why number one is not were number one always is.....? I can pull it and do a 180 and the rotor will match the cap on one, not a big deal.. just strange if you watch the video and this is the same thing I've done for 20 years.... It's just weird doing something new I guess....

oneradride · 09-14-2011, 08:38 PM

Absolutely will be primed prior to firing........

ss3964spd · 09-14-2011, 08:50 PM

Doesn't make any sense to me either. The reality is that you can call any one of the dist cap posts #1, and line up the rotor to point to that post, and have cyl #1 at TDC on the compression stoke, so long as you wire the rest up following the firing order.

seapuppy · 09-14-2011, 10:00 PM

in order to find tdc..it's best to have the valve cover off so you can see the rockers moving..then move the crank by hand until you see the intake open and shut..that's compression...tdc fires on compression....as dan stated...any post can be assigned #1..but the rest of the firing order needs to be correct as the distributor spins...

SP

oneradride · 09-15-2011, 12:36 AM

I get all that and I really appreciate everyone's advice. There just a right way to do things and then there's the 'other' way...... Both will get me where I need to be.. I just was hoping someone might know the reasoning/logic behind the difference. It's not going to keep me awake at night.

And SP I agree, I found TDC comp- with not only the valve covers off but the intake also.... I know that parts right...

ss3964spd · 09-15-2011, 12:44 PM

Quote:

Originally Posted by oneradride

It's not going to keep me awake at night.

Lucky you - that kinda crap drives me outta my mind. LOL

Sounds like you've got you arms around it pretty well. I'll likely be dealing with the same task this weekend as it looks like the 489 for my '66 will finally be going in.

Good luck...

Dan