4.3L Merc questions

[denhajm]

4.3 mystery water hose

Hello, I would really appreciate help in identifying this hose while I have the exhaust off as I'd like to replace it. I believe it takes water from the outdrive, to the engine. I've looked through both the engine and outdrive exploded diagrams as well as the online tech manual 7 and so far cannot identify it (p/n). Engine s/n: 0C861086, Drive s/n: 0D305493. Please see the photo with the arrow pointing to the hose. It comes up through the transom then runs to the port side of the aft part of the engine, then runs forward under the port side--perhaps to the power steering cooler. Thanks!

 

[denhajm]

I'm changing the exhaust manifolds and risers on my '90 4.3L mercruiser, engine s/n: 0C861086. The middle exhaust port on the port side of the engine has much more fouling on it than do any of the other 5 cylinder exhaust ports. Is this a sign of bad oil rings? Insufficient combustion/spark?

 

[denhajm]

4.3L starter, replacing with what kind? New bolts p/n = ?

Hello, I have my exhaust manifolds off for replacement and thought I'd clean all the electrical connections I can now access. When cleaning the starter and solenoid studs/connections the stud securing the yellow wire with red stripe on the solenoid broke off quite easily. Based on the appearance of the starter, its has been on this 1990 boat for some time (engine s/n: 0C861086) I removed the starter from the engine and would just as soon replace the starter/solenoid assembly. It has 11 pinion teeth, and some starters I'm seeing have 9. Per the parts diagrams, the superseded starter I need is p/n: 50-863007A1
This appears to be the new permanent magnet type of starter, which is smaller? I'd like to replace the starter bolts too, but with this different starter, do I need bolts of a different length then my existing starter? I'm not having any luck with ID'ing the starter motor bolt p/n I need.
So 2 questions: 1. does 11 teeth vs 9 teeth matter? 2. what bolt p/n do I have, and what bolt p/n do I need if I go with the new type starter that I hear is smaller? I want to have an easy, drop in, bolt up situation here. I've heard of folks dealing with shims, and would like to avoid that if possible. Thank you!

 

[alldodge]

It's item 18 if you have the old design
http://www.mercruiserparts.com/bam/subassembly/31478/951/150

Or item 21 if you have the new design
http://www.mercruiserparts.com/bam/subassembly/31478/951/160

Easy to tell, look at the thermostat housing in the diagrams

 

[Bondo]

I believe it takes water from the outdrive, to the engine

Ayuh,.... That's correct,.... Transom to P/S cooler hose,.....

Let's keep all yer various questions 'bout yer motor in One thread, rather than many threads,.... Ok,..??

I'll merge the 2 ya just posted,....

 

[Bondo]

The middle exhaust port on the port side of the engine has much more fouling on it than do any of the other 5 cylinder exhaust ports. Is this a sign of bad oil rings? Insufficient combustion/spark?

Ayuh,.... The spark plugs will tell the story of what's goin' on in the cylinders,....

When ya pull 'em for inspection, do a Compression, 'n Leak-down test, for the full story,.....

 

[Bondo]

So 2 questions: 1. does 11 teeth vs 9 teeth matter? 2. what bolt p/n do I have, and what bolt p/n do I need if I go with the new type starter that I hear is smaller? I want to have an easy, drop in, bolt up situation here. I've heard of folks dealing with shims, and would like to avoid that if possible.

Ayuh,..... The critical issue with Chevy starters is the bolt pattern, Staggered like yer's, or straight across like some,....

Pinion tooth count don't matter,.....

Merc is now usin' starter bolts that have a shoulder, 'n extended smaller heads on 'em,....
The hex head is 'bout 3/4" long, 'n uses a 1/2" wrench, rather than a 9/16" wrench as most 3/8" bolts,...

Don't have the part numbers, but other posters might,......



'n, Yes, go with the new mini-motor starter, no shims should be needed, nor used,....

 

[denhajm]

Mystery Hose: AllDodge--thanks for your help! I have the 'new design'. I think the hose I have is actually item 22 on that drawing, 'hose, fluid cooler, 3/4" ID'. That seems to be the one coming from the transom area and its longer than 21. I'm now armed with a p/n! Thank you.

 

[denhajm]

No Title

Starter bolts-- mine that came out are exactly the same length...not different length. 9/16" head, overall length just under 5". See attached picture.

 

[denhajm]

No Title

Exhaust fouling/spark plug. Pulled the center port spark plug (which has higher exhaust fouling at head exhaust port) and the spark plug right in front of it (this plug's exhaust port is also in the photo higher in this post). They look essentially identical to me.???

 

[Bt Doctur]

plugs look good, a bit on the hot side or the carb is running lean, starter looks like it went swimming too.

 

[Bondo]

Starter bolts-- mine that came out are exactly the same length...not different length.

Ayuh,.... My bad, I changed the post, was thinkin' one thing, 'n typed another,....

Straight pattern starters use a short bolt,.....

 

[denhajm]

a. So now I'm trying to zero in on the p/n for new starter bolts... For whatever reason, the starter bolts aren't on the mercruiserparts.com starter page drawings. As for the starter taking a 'bath'. I'm not sure if the engine compartment was that flooded prior to me owning it or not. One possibility is a cooling water leak dripping down on it over time?... But, it certainly can't hurt to swap it out with a new one.
b. I'll have to research how to do the compression and leak down tests...May be in the late Don S's adults only section.

 

[denhajm]

I believe this is the proper starter bolt: http://www.iboats.com/Starter-Bolt-18-8402-Sierra/dm/cart_id.969415050--session_id.345675188--view_id.345612
This should work with the new PMG starters?

 

[denhajm]

Here are the compression test numbers: #1 152psig, #2, 152, #3 162, #4, 164, #5 150, #6 154. With these seemingly good numbers, is there any purpose in doing a leak down test?

 

[denhajm]

Okay, did the leak down test using a OTC #5609 cylinder leakage tester kit I got off Amazon. I've never done this before so it took me a while to get the proper piston positioning for each of the 6 cylinders. #1 10%, #2 8%, #3 6%, #4 7%, #5 10%, #6 11%. This was done on a cold engine, due to the state of partial disassembly (no exhaust manifolds/elbows). This is on a 1990 SeaRay BR200 with (as far as I know) the original engine. Looks good, no?

 

[alldodge]

Yes, looks good

 

[denhajm]

Installed Merc exhaust manifolds and risers this morning. After the day's activities, came back home tonight, looked things over, checked engine oil level, hooked up to muffs with water on and the thing started right up (new starter might be a strong one)! It jumped right to life which is not what I expected after sitting winterized for several months. I had a pegged oil pressure gage to turned off the engine, checked and cleaned the sending unit connection and that solved that. Started/stopped engine probably 5 times, all at throttle stick straight up, no choke or anything. Started great a purred at about 800 rpm on the dash tach. After about two minutes at idle, I pushed in the neutral button and eased the throttle forward. I wanted to get from 800 rpm to about 1200. The thing never got there. Started running rough, shuddered and died. Tried to restart several times. Finally got it started but only with near WOT position in neutral to get it going then quickly dropped throttle back to 1,000-sh rpm. Thing ran really rough. Blue/black smoke coming out of exhaust (absolutely clear exhaust for the first few runs this evening when it purred). I had this happen a couple of time last summer where at the dock, it was running rough at low rpm and smoking, but then it ran fine when we actually got under way. However, now I cannot get beyond 1,000 rpm (again on the muffs, not in water) without it dying. Old gas from last September, 1/2 tank. What might be causing this rough running at low speed and blue/black smoke in the exhaust? Could 1 or 2 cylinders not be firing for some reason and I'm blowing out partial burned or unburned fuel? I never got any real heat into the engine tonight due to only running 2-3 minutes.

 

[alldodge]

blue/black smoke in the exhaust?

Your carb is flooding the motor with gas. It needs rebuilding or at least the float level reset.

 

[saltydogjeff]

I think that makes sense with the fouling too because the heavier gasoline doesn't travel out to the outer cylinders.