Boat is at the shop.....still no smoking gun.....

[gidds]

Merc Model 1350 1971 Inline 6.....

Upon numerous folks replying to the following pic and me chickening out on the link and sync (not the proceedure but thinking I would mees something up further).....I took the boat to the shop.

I removed these plugs to replace and tested comp. and got 115,125,125,117,125,120 respectfully.

So far the shop has performed the following:

Mech called and said he also checked compression, checked spark, checked throttle (repaired the retention body where cables enter engine), adjusted timing- max was high so he adjusted to low 20's (I will verify exact setting when I talk to him this week), checked carb needles and said they were close to perfect, checked throttle opening. He said it ran great at the shop and was impressed with the way the engine ran for its age. He said it was quite "peppy". He said he had about two hours labor into it and I was albe to pick it up and try it out or he could take it to the lake and see for himself. I bit the bullet and asked him to take it to see how it does under load.

I then got the "your boat is sick call" and he gave me some options and asked what I wanted to do. He and I agreed to look into the fuel delivery first then into the carbs. I had rebuilt the carbs a while ago along with the previous owner and we were extremly careful to make sure everything was OK, however I agreed to have him check them also. I spoke to him Friday and he was waiting on gaskets. He mentioned that one of the floats needed to be adjusted but the carbs did not look that bad.

So far I have less then $100.00 parts and about 4-5 hours labor into it. He mentioned two things that bother me 1) he said he has not found the smoking gun and that 2) the inline 6's have a hump at about 3000-3200 rpm (something about the tuning of the exhaust, etc.). I have never seen the boat run over the "hump". He also mentioned that there is an exhaust plate that may be damaged that leaks exhaust back into the engine not allowing 100% fresh air into the carbs (I may not have relayed this correctly), however he didn't think this was the issue.....

My question is -- what to do next? how far do I go? Any ideas?

Thanks a bunch in advance!!!!!

A little more info....mostly ran about 2700 to 3000 rpm at 25mph max with a 19" pitch prop. 16' glastron trihull. Mech also stated that the tach (original merc.) seems to be correct. He was suprised that it did not run good in the water after running good in the shop.

 

[Texasmark]

Re: Boat is at the shop.....still no smoking gun.....

How'd he run it in the shop? Did he run it on muffs, or did he put a test wheel (prop replacement) on it and run it in the tank.

If on muffs, he didn't load the engine like you do in the real world. If he ran it in the tank how good did it run? Could he get 6k rpm's out of it? Normally you are fuel starved if it will run in N and won't take a load.

Personally, I can't believe your plugs are that diverse in color which indicate what's going on in the cylinders. They just aren't all hitting the same. Did you install them all at the same time? Have you started over with a new set? Only one looks fireable (#6) and it looks like you just put it in and never fired it.

Mark

 

[Chris1956]

Re: Boat is at the shop.....still no smoking gun.....

GIDDS, The spark plug colors indicate that cylinders 1,3 and 5 are running too lean, and cylinders 2 and 4 are running too rich. Number 6 cylinder is likely not firing due to water ingestion. I cannot imagine why you have such a difference between cylinders 1 and 2 (which share a carb) and 3 and 4 (which share a carb). My only guess is that the carb is flooding slightly, and gravity caused this extra fuel to settle into the lower cylinder, making it run rich. I think a carb check is in order. Make sure the inlet needles are good and the float level is set properly, and the main jets are clean.

On number six cylinder, the water injestion could be caused by bad crankshaft seals in the lower end cap, or by a hole in the exhaust baffle. Both require that you remove the powerhead to fix properly. Both are therefore fairly expensive.

If you cannot get it to run properly, you might give Clams Canino a shout and see what he would charge to rebuild it for you.

 

[gidds]

Re: Boat is at the shop.....still no smoking gun.....

I think he ran it at the shop with mufflers on it. But he took it to the lake and thats when the "your boat is sick" statement was made.

The plugs in the picture were removed in late october. They were all installed early in the year, at the same time.

Again, he said the needles seemed to be close if not right on and the only thing that he saw may be a problem was one float was out of adjustment. He didn't think that this was the smoking gun.......

I am expecting a call tomorrow saying that he got the gaskets in and is going to complete the carbs....

I don't know how much further to have him go? Should I wrap it up with him and call Clams......

 

[Texasmark]

Re: Boat is at the shop.....still no smoking gun.....

Follow along with what Chris said.

Forgot, but his comment about water ingestion could easily explain #6. That could possibly be caused by a "corrosion" hole between the combustion chamber and the water channel cooling it.....had an engine with it once.

Being a '71 steers me to a magneto ignition, points and all which says if fire to 2 and 4 were weak, beins they share carbs with 1 and 3 as Chris mentioned, it might be due to the plugs fouling (they look horrible) or bad sparkplug wires, distributor cap (fouled terminals, insulation tracking) sort of thing. You could ohm check the wires and run it at night looking for lost spark, sparking cables, plug insulation things. Your compression test results provide no clues here.

Don't know if #6 is getting water (sure looks like it) nor how much.....too much to support combustion hence you lost that cylinder.

Don't know how this engine on your boat would respond to 5 cyl operation.

Did your mechanic put new plugs in it and these are just what you/he took out or is this what he's running now and basing his comments on? Hopefully not. If new, why not pop all 6 and look at them since they have a little time on them. Maybe some clue there.


HTH

Mark

 

[Yepblaze]

Re: Boat is at the shop.....still no smoking gun.....

#1 plug is the color of piston.

 

[daveswaves]

Re: Boat is at the shop.....still no smoking gun.....

Heres another interpretation, 1,3,5 are firing normally, 1 has been running hotter due to advanced spark and location in block, your mechanic has brought the spark advance down to low 20,s (read 21) so should be OK. You likely have reeds that no longer close completely (worn,tired) and the carbs have been adjusted rich to accommodate, as a result, 2,4 6 are running rich and fouling at idle. You never get above 3000 rpm so 2 and4 never get burned off, there is water ingestion, likely from exhaust cover/water jacket at number 6 which is getting steam cleaned.
Only you can decide what to do but if it was mine it would be time to pull the block apart and rebuild or replace.

 

[gidds]

Re: Boat is at the shop.....still no smoking gun.....

I spoke with him (the mech.) again today. This is what I understood him to say....he spoke with another gentleman who has worked on Mercs for years and he thought that it sounded that the exhaust extension may have an issue and exhaust is re-entering the carbs / engine.....

Does this sound possible?

Also......what is a budget for a rebuild? $1000, $5000, $10,000......

 

[Chris1956]

Re: Boat is at the shop.....still no smoking gun.....

Gidds, I never heard of the issue your mechanic thought up. The exhaust extension is a simple aluminum casting, that should have no effect. Now I did have an exhaust leak into the cowling, which did stave the motor for oxygen. But that was easy to find - motor ran better with the cowl off.

As for rebuild cost, the pistons are $100 ea, and boring is $50 each. Labor will be 4-5 hours at $100/hour, as a minimum.

I just bought a '93 Merc 135V6 for $1K. That motor has the newer PTT, a 40A regulated charging system and more power than any inline six, especially low end power. So unless you have some sentimental attachment to that motor, pick up an newer used one!

 

[daveswaves]

Re: Boat is at the shop.....still no smoking gun.....

I would have to agree with Chris, time for a change. Your mechanic is guessing. I said that I would rebuild it, but I have an emotional attachment to the inline 6 and all its quirks.

 

[gidds]

Re: Boat is at the shop.....still no smoking gun.....

I'm starting to get the feeling that I am going to spend $400-$500 just to get my boat/motor back and the mech telling me it needs to be rebuitl. Granted the mechanic has been ok I think that the consensus is that the engine is soon to be done. With that being said should I run it until it dies? It runs good in the 3000K / 25mph range.....

Do I trade it? keep it and take it apart for learning sake? part it out?

I enjoy the fact that the enging and boat are both 1971 original and both are in great shape. I also like the idea of having an inline 6. This situation sucks.

 

[Texasmark]

Re: Boat is at the shop.....still no smoking gun.....

Just for grins why not do a decarb......see archives. Won't cost but a few bucks, won't take long and you surely won't make things worse. May even be pleasantly surprised.

Years ago I did an overhaul on a 3 cyl OMC. Pulled the powerhead and had a mech do a .030 over. I did all the rest of the labor. Cost was $750 for that and $250 worth of incidentals to give you some idea of cost.

Just dust your plugs off with some Berryman's chem tool when finished rather than replace as mentioned as you just replaced them.

Mark

 

[Chris1956]

Re: Boat is at the shop.....still no smoking gun.....

Gidds, Unfortunately there comes a time of dimishing returns on an old outboard. This is due to the deterioation of the block and its associated parts. Even if you can do the work yourself, you will at best patch the thing until the next time(soon).

In your case, you need assistance from a shop. Modern shops are not familar with the inline sixes, distributors etc., and will not be able to do the work cheaply, and may not want the business.

Let's take your specific case. I think you have water infiltration into no 6. I think it is likely due to bad lower seals, a leaking exhust baffle, a leaking inner water jacket cover, or all three. To buy new seals is $25, inner exhaust cover $100, Exhaust baffe $125, and to have them installed, means puling the powerhead ($250??). If you fix them all it will cost $500. If the pistons need work, add $2-300 more. Oh yeah, if you break some bolts due to corrosion, it will cost more to get them drilled and tapped.

You will have spent $700 on a motor that is worth $300 (max), and you are now waiting for the trigger and/or switchbox to break ($2-400).

For a bit more money, you can get a better motor, with inherently more reliable subsystems, mechanics who can work on them and more readily availible parts.

 

[daveswaves]

Re: Boat is at the shop.....still no smoking gun.....

Additional info that may help you decide.
http://cgi.ebay.com/ebaymotors/Merc...ryZ26455QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[Texasmark]

Re: Boat is at the shop.....still no smoking gun.....

Here we go again. In dave's ebay ad, the guys who overhauls I6 Mercs for a living talks about the '88 115 being prop shaft rated. Yesterday I was fed that Merc always propshaft rated their engines.

I wish people would make up their minds which it is.

Mark

 

[daveswaves]

Re: Boat is at the shop.....still no smoking gun.....

Mark, the early mercs were indeed measured at the flywheel. As Clams says in his dialog, early 80,s is when they started measuring at the prop shaft. For example, the 1984 90 hp inline 6 is exactly the same powerhead etc as the 75 115.

 

[gidds]

Re: Boat is at the shop.....still no smoking gun.....

OK....So I called a couple of local dealers that said a used mid-hp engine on good working order is a needle in the haystack. I could get a modern used 90 HP 2 stroke in the $3K-$4K range and a new 115 in the $10-$11K range. Now I keep in mind that they are wanting to sell a new engine...... there are not alot of local dealers that have used engines around.

I emailed Clams and with the "ebay" powerhead, install, hotel, gas (4hr trip), cheap dinner, 6 pack, etc. I could probably have the power head replaced replaced for less then $2000 (guessing and including the current bill from the shop). I know that this may be a band-aid but I could probably squirrel up this as opposed to a new engine.

Any input......

One more question...."Powerhead".....does it include the water jacket, exhaust baffles, reeds, etc.?

 

[daveswaves]

Re: Boat is at the shop.....still no smoking gun.....

One more question...."Powerhead".....does it include the water jacket, exhaust baffles, reeds, etc.?[/quote

This is a question you should ask directly of Wayne, (Clams). Call him, his number is in the ebay ad. In no way is this a bandaid fix, the rebuilt power head will be better than new, IMHO.

I would negotiate with your current shop on the bill since they have not really performed any work of specific value with regard to your problem.

 

[Texasmark]

Re: Boat is at the shop.....still no smoking gun.....

Thanks dave on the hp rating question.

On the shop repair, I used to repair things for folks and barring any parts I installed, which had to stay installed, I didn't charge the customer if I could do him no good. I chalked up my losses to the cost of getting educated.....seems you learn something every time you attack a problem.

Course the other side of the coin works too. After getting educated, If I could fix a problem in 5 minutes, the customer still paid the flat rate (book rate to fix a certain problem) for the work......I mean fair is fair.

Some shops charge regardless......course with that philosophy, the quest to fix the problem is not as intense....little human nature.

My 2c,

Mark

 

[Chris1956]

Re: Boat is at the shop.....still no smoking gun.....

Gidds, I ran into exactly the same issue when trying to find a used 115-150HP. I visited the new boat/motor shops and they had nothing used that wasn't $3-4K. In addition, I needed a 20" shaft, which is hard to get these days, because all 115+HP motors have a 25" shaft.

I finally ended up at a used boat dealer. He gets boats and motors in trade for other used boats/motors. It took a bit of discussion with him, since he is a crusty character (slimedog is his first name) but I was able to find a motor he took in trace, which fit the bill.