TOPIC: carb difference 1350 - 1400

Would I gain anything going from stock 1350 carbs to stock 1400 carbs? I'm not sure I need to, just curious.

Thanks!

Frank

I can't seem to get a number for the 1400's but the 1350 has the WMK-4 carburetors and they have the same main jets etc... as the 1400's
I am sure others can pipe in and tell you how to juice her up a bit more.
As far as cyl # 3 being 118 it could be lower from sitting or the rings could be carbon'd. I sprayed some sea foam into her real good and rolled her over easy every now and then. I used to be of the mindset to think they will free up once she runs but I tend to open em up for a look so I know. If they just need to be free'd up and the grooves cleaned then it is worth it.

1. 122
2. 125
3. 118
4. 125
5. 132
6. 124

Sounds good, thanks Jim.

I don't know. Those compression #s seem good, even between the lowest & highest, there's just a bit over 10% difference. I'll keep spraying sea foam or marvel into them, see what happens while I'm working on other stuff. I think 1st I'm gonna do that manual thing I suggested to ya, i.e., just make up a 1350 manual from my original merc service manual that covers those motors by scanning pages specific to the 1350.

Enjoy yer evening!

Frank

Jim is a smart man. I would pull it down and look for stuck rings. Ive ran a few motors that I thought would "free up" that had "ok" compression for a year or so. Then when I finally had time to pull it down and replace top and bottom seals nearly all the rings were stuck on one side of the piston.

I have had good luck replacing top and bottom seals, loosing up old rings. Doing a very light hone and putting them back in if I dont have new rings. I tore down my 900 just to check on it and put new top and bottom seals in. Low an behold the rings were stuck :0 !

By the way the 1350 is a pretty potent motor in stock form. I would not waste much time trying to make it better. You would be better served splitting the case to see how things look quick replacing seals and rings if you have time. A 1350 has high dome pisotns in it. So 118-125 is getting tired.

Usually when #3 is lower than the rest it needs some sort of help FYI. Its worth the 1/2 day to look inside

You will see a LOT of performace gain from your 1000. Get ready to hang on.
Conrad

First of all, I gotta agree with ya Conrad, Jim IS a smart dude. I almost hate saying that cause I don't want his head to swell and cause him more trouble...

I hear ya. I'm not in a rush, as the old 1000 runs good, and I don't need the 1350 ready next week, or the week after. I was gonna take time and pretty it up anyways. I'm a bit short of cash right now for parts anyways, too many other things demanding my time & money, but I love working on motors.

Thanks for the advice Conrad, it is much appreciated. I'll keep y'all posted!

Frank

milkdud wrote:

Doing a very light hone and putting them back in if I dont have new rings.

Conrad, if it's two ring, I can get a set from NAPA (i.e., they can get them). If it's 3 ring, I can't get a full set (from NAPA). So if I pull it part and let's say the rings are not bad, are there tricks or tips to the honing process? I've never done it before, but can get a hone from NAPA that does 2-7" for a very reasonable cost. And if I did get new rings, is it the same deal - lighlty hone?

This is all a ways off, but I like to be prepared! I have more than enough to do.

Thanks for the help, I do appreciate it.

Frank

Frank:

Keep in mind these motors also have a tendency to egg shape cylinders and pistons, this does not always show up with a compression test. It should be line bore gaged to check for this condition.

About fifty percent of the motors I do that have a direct charge piston configeration has this problem, which will show up when putting the motor under a strain. Now your boat is very light so that may not be a issue. The reed blocks also need to be checked for wear.

Take the time to do it right Frank, you still have the other motor to use in the mean time.

Darrell

ClassicMerc wrote:

It should be line bore gaged to check for this condition.

How does one do this, or who does this?

[/quote]The reed blocks also need to be checked for wear.[/quote]

How does one check reed blocks for wear?

Thanks Darrell. Yes, I have time, actually much more of that than $!

Frank

Frank,

Id dig into it and pull the rotating assembly out and look what you got. I think most/all of those 1350's are the 3 ring pistons.

Judging by your PSI numbers you will want to put new rings in and not waste time on the old ones. When you hone you want to get an even cross hatch pattern on the entire bore. Honing is more of an art then a science. I use a cheap hone from NAPA and it works.

Darrell is correct on the out of round holes you will find with these motors. When you put your hone in and make a few passes you will see how bad it is. Your highs and lows will become immediatly apparent because the flat stone will not reach the low wore spots. When really wore the only thing you can do is move up a piston size. Then your talking $$$$$. Remember the latest power port low domes will be available for this motor. And the High Dome power port pistons will work too. You probably will never find original 1350 pistons, which is not a problem, because the later power port pistons are a direct replacemnt.


Now when I did my 1500 last year. My bores were borderline. But I honed them put new rings in and ran it. It does very well, but another mechanic may have bored it and put 6 new 15 over pistons in it.

The reed blocks will show wear, by the grooves being flattened down. If the grooves look crisp and no sign of major rubbing then they are fine. If they are wore down or mushroomed down then they have a problem.

All of this starts with cracking open the block and looking at the rotating assembly.

Conrad

Thanks Conrad, great advice once again, and very helpful. Some of this stuff I will be back to you guys on, but bear with me, money is tight but so is time. I guess maybe the 1st thing I should do before pulling the parts motor apart or making up a 1350 specific manual is to tear this baby down, get a hone, and see what I have.

This block I have is #29999927, i.e., an early one. Funny that NAPA only shows 4 of the ring sets for 3 ring pistons in the country, and a boatload of 2 ring piston ring sets. I suppose I could find a couple more 3 ring sets somewhere.

So this art of honing - hmm, maybe NOT buy a hone, and have somebody else do it?

"Remember the latest power port low domes will be available for this motor. And the High Dome power port pistons will work too. You probably will never find original 1350 pistons, which is not a problem, because the later power port pistons are a direct replacement." What you're saying is there are pistons available, just not OEM. Got a Sierra # (or #'s)? I could check with NAPA.

This project could take a while if it gets expensive, just because I am not "loaded," and toys get paid for with cash, not credit. I don't mind, I would rather do it right, or as right as makes reasonable sense. My 1000 has treated me real well the last couple of years, I have no complaints.

Thanks again for the help, I appreciate it.

Frank

If your lucky, you hone it. (not that hard really) put new rings in put new top and bottom seals in then run it...

Top and bottom bearings just check if they are smooth. If they have any roughness or catches to them replace. The bottom is cheap and the top is a bit more.

The 3 ring varient is available from ishopmarine.com and crowleymarine.com I beleive.

There are Sierra, Wiseco, and Mercury pistons still available for this motor. They will most likely be low dome 2 ring power port pistons. I find new high dome pisons on ebay all the time.

But hopefully you dont need pistons or maybe just one.

Good luck, I may start working on my 1350 someday as well. It needs new rings etc....
Conrad

Cool, thanks Conrad. When I put my 1000 back together I put new seals, bearings and o-rings in. Let me see what I can do. First I got a compressor system problem I gotta figure out. Got plenty of pressure at my 90 gallon tank, but when I run my impact wrench, it goes zing!, then dies right off. I got two of 'em, same thing. Tried my blower nozzle, same thing. Got me puzzled to say the least!

Frank