Need help 94 Mercruiser 305

[JustJason]

Re: Need help 94 Mercruiser 305

I know what you mean john.
This thread reminds me of a guy i had about this time last year.
I had this guy call me up and say he had a merc 350 blah blah... overheats. Tells me he had a buddy put a waterpump in, but still overheats....
So i go down...(waste of time) The guy has something... i don't know what it was... but it was something that had 8 cylinders... it was a gm small block, painted black. An osco manifold on 1 side and a glm on the other. The thermostat housing (after some research) turns out to be off a crusader. Theres no serial numbers on anything.
I took 1 look and said nooo way jose... see ya later, bye.
Moral of my story.... i never believe anybody anymore when they tell me they have something... unless they back it up with a serial.

 

[Bry21317]

Re: Need help 94 Mercruiser 305

Logic would say... it ran cool before the new parts, and now its running hot. So why is this guy tearing into his waterpump? Logic would say the waterpump was plenty fine on the factory parts. Also... this guy says that whatever his mechanic does he's going to tear down and double check.... what's the point in that???

Jason,
Yes the boat ran cool before this mechanic touched it. The boat has 145 hours on it. It runs like a champ. The compression, after the mechanic worked on it, is 145-150 across all 8 cylinders. What I had the mehcanic do for me was install my new Intake Manifold, Carb, Distributor cap, Rotor, Spark Plugs, Prop Shaft(old one was bent) and a New Water pump. Some this, I just had the parts and was going to do myself, but had him do it all while he had the boat. This is why the Impeller was replaced, I am the type of person that will replace that every year to make sure, its not messed up. I did not know when it was last done, as I had just purchased the boat last April. Ran it for one season, then had all the work done. This is why I had a new Impeller put in.

Hope he's not paying this guy.
This is what you get for playing around with motors that you know nothing about.

Yes, I did pay him, the first time for all the work as described above.


This is where i'm at right now......
1. Incompatable parts- I got all Merc Parts, rather that is what he put in or not, I am not yet sure.

2. compatable parts installed incorrectly- MOST LIKELY!

3. Incorrect plumbing- I double and triple checked this last night to the Merc Service Manual, all correct.

4. bad head gasket -Would not think this is the case with the Compression numbers. I will run my own Compression numbers again this weekend.

5. bad circulating pump- This is possible, I will not rule this out.

I'd be curious if clear hose was put inline from the water input hose... bet it hasn't been yet.

Not that I know of. I can do this myself now, I have the boat back. Tell me what to do with this, tie the clear hose into the Power Steering Cooler and watch for Air bubbles?

Overheating with a thermostat is one thing... overheating with no thermostat is a different animal.

There was a damaged gasket, that he said was in the water pump. Did not have the Silicone bead on it, or something of that nature.

1. because this is now a frankenmotor... he should grab a notebook and pencil and start drawing out a cooling system diagram for the motor.

The cooling system is still identical in diagram to the Merc Service Manual for a 6 hose Thermostat housing. I have checked and rechecked this.

2. replace water inlet hose with clear test hose.[/quote
I will do this, tell me what to Look for and I will do it this weekend.

3. pressure test the block

I will do this again, I have a pressure testing kit in my garage. I will do it myself and write down all numbers. He did this, but I do not trust his readings now. They all came out 145-150.

4. leakdown the cylinders

Can you tell me what this is? I have not yet found or seen this in the Manuals.


Now for what is up with the boat. After answering all the questions above from Capt. Jason. I got the boat back last night, so of course I had to fire it up. Well hes what happened on the Muffs, these ar ethe circular mercruiser muffs with the rod that goes through the lower unit, the water hose was put on 1/2 pressure.

I fired up the engine and it ran like a champ, started right up, and water started coming out of the Thru Hull Exhaust within 10 seconds, as it always did before. The water stream was good and it was flowing nice. The Exhaust risers were staying nice and cool. The temp started to creep on the gauge, and finally got up to 175, then it went a little higher. So I did not like this. Well I took the Thermostat out to make sure that he had not removed that or the spacer again. Well come to find out, I find there is NO Freaking O Ring under the Thermostat.

This O Ring was put in by me and was in there with the thermostat. So my guess is when we were at the lake last Friday, when he pulled the Theromstat out, he did not pull the O Ring out. So now, where the hell is the O ring? Would it be stuck in one of the hoses, or would it have made it all the way out of the Exhaust and into the lake? This is my main concern now, where it went.

So the boat ran like a champ but it did get a little warmer than I would like. I think it should be back at 165-170, which is where it always ran before. Now its a little higher and I checked and the Thermostat is still the Mercruiser 140 Stainless Steel one.

I am going to get a new O Ring today from the dealer, and some new Gaskets for the Thermostat housing.

Thanks for all the help. I should know more by this weekend for sure. Once I get the temp to stay steady on the Muffs, I will retry at the lake and work on the carb.

I also noticed that he turned the Fuel pressure up on the Regulator from 3 to 5.5 which I was going to do anyways, which is stated Directly in the Manual of the Edelbrock Carb.

Bryan

 

[Bry21317]

Re: Need help 94 Mercruiser 305

Here is My Merc Serial number, if you wish to have that to back it up: 0f266510.

All stock other than the New Edelbrock RPM Air Gap Intake and the Edelbrock 1409 MARINE Carb and the K+N Flame Arrestor.

Here is a picture

Thanks for all the input. I can do the work myself also, so I am not to worried about it. Just pissed I paid someone that screwed my crap up, it will be the last time it is taken somewhere.

Bryan

 

[JustJason]

Re: Need help 94 Mercruiser 305

will write more later... but that's no flame arrestor... that's an air filter.
That's gotta go....

 

[Bry21317]

Re: Need help 94 Mercruiser 305

CaptJason,
No Prob. I know that I wrote a book, trying to answer everything.

Here is where I purchased the Flame Arrestor from, I gave him this part http://store.summitracing.com/partd...art=KNN-59-3364&N=700+311144+115&autoview=sku

It states CG Aproved.

Bryan

 

[bomar76]

Re: Need help 94 Mercruiser 305

will write more later... but that's no flame arrestor... that's an air filter.
That's gotta go....

Another of the many things you have been wrong about...

K&N has marketed USCG Marine Certified flame arrestor for a very long time...
http://store.knfilters.com/marine/boats.htm
and it certainly looks like this one:
http://store.knfilters.com/search/product.aspx?Prod=59-3364

 

[bruceb58]

Re: Need help 94 Mercruiser 305

will write more later... but that's no flame arrestor... that's an air filter.
That's gotta go....

That is a K&N marine spark arrestor. I wouldn't necessarily pay the money for one but that is definitely one.

http://www.knfilters.com/search/product.aspx?Prod=59-3264

 

[bruceb58]

Re: Need help 94 Mercruiser 305

Bry21317,

Have you double checked your temp with a portable IR gun? I would definitely do that and also check your exhaust riser temps.

 

[John_S]

Re: Need help 94 Mercruiser 305

The CG numbers will be stamped somewhere along the rim. I made sure they were there on mine, just in case I was boarded for an inspection. I could see that an untrained person questioning what looks to be a paper element. The county sheriff and DEC patrols our lake, not the coast guard.

If you know that your old stat was a 140, than you might have had an issue before the work was done. 175 would be too high for a 140 stat. If anything, while running on the muffs you should be lower than what you would typically see at the lake. Low rpms plus constant "cold" temp water.

 

[Bry21317]

Re: Need help 94 Mercruiser 305

Have you double checked your temp with a portable IR gun? I would definitely do that and also check your exhaust riser temps.

I will check this as I have an IR Temp Gun.

It is warm at the very bottom of the thermostat housing below the thermostat, as I did put my hand down there last night to check the temp and it was alot warmer than the top half of the thermostat housing.

I do not know what Thermostat was in there, but I know this is the one that the Dealer said was for my engine, by Serial number, so this is what I have now put in there.

I just got back from the dealer and got new the 2 new gaskets for the Thermostat housing and the new oring.

I am guessing that since there was no Oring below the thermostat, that it was leaking, and that could be causing it to heat up higher than it should. I guess I will find out tonight when I get home and put the oring and new gaskets in.

I will also check the temp with the IR Temp gun. Where should I get readings from?

Bryan

 

[JustJason]

Re: Need help 94 Mercruiser 305

My bad... i didn't realize that product existed. (k&n) I does look like an air filter from my house... but as long as its cg certified i guess it doesn't matter.

Byran... shoot the sides of the block, right around the freeze plug location. Shoot the manifolds and risers. and shoot the hoses before and after the t-stat.

 

[JustJason]

Re: Need help 94 Mercruiser 305

Not that I know of. I can do this myself now, I have the boat back. Tell me what to do with this, tie the clear hose into the Power Steering Cooler and watch for Air bubbles?

Look and find where the water inlet hose comes from the the transom plante and comes up and connects into the t-stat housing. Disconnect it and measure it... its 5/8ths or 3/4s.. i don't remember. Then run to home depot and get some clear line of the same size and a nipple to put 2 lines together, along with a couple of hose clamps. Splice in the new line to do your testing, and hook it back up to the t-stat housing. when your done, remove the clear line.

 

[bruceb58]

Re: Need help 94 Mercruiser 305

I would measure right at the temperature sender. That will verify if what you are reading on your guage is accurate. Measure the risers themselves. If you don't have a good flow of water, these will get very hot.

 

[Bry21317]

Re: Need help 94 Mercruiser 305

Well I put the new Oring and Thermostat housing gaskets in, and that made no difference it is still running right on up to 175. I then found a hose leaking some gas around the Regulator, so I need to take that back off and work that issue out. I shut it down when I found this.

I will get the clear hose and try that this weekend also. I will also shoot all spots with the IR gun, to make sure it is really overheating. I also pulled the wires off both of the sender units on the Thermostat housing and put them back on, trying to remove any corrosion that might have been on there.

So where should I look for the old Oring gasket, any takers on this? Where it might have gotten pushed and stuck? I looked in the Thermostat housing and its not in there. I am thinking I need to pull all the hoses from the Risers and Manifolds and see if I can find it in one of those hoses. I do not think it would have blown out the exhaust pipes but I do not know.

Bryan

Bryan

 

[wca_tim]

Re: Need help 94 Mercruiser 305

Is there any chance at this point that it would run up to 175 and stay there? If so... could be that the thermostat is opening there and worth simply trying a new one. it's not absolutely unheard of for one to open at the wrong temp... could either change it out or reat it up in a pan of water on the stove with a good thermometer...

 

[Bry21317]

Re: Need help 94 Mercruiser 305

Wca_Tim,
I tested the thermostat on the stove before putting it in the boat. I have another one that is the brass model that also opens at 143 degrees. So this is the second one.

I will try the clear tube this weekend to see if I see a bunch of bubbles. I have a full new water pump kit with all gaskets and a new SS housing also. So I might have to end up putting this on, to make sure there are no air leaks anywhere.

I am also using the Mercruiser Round muffs with the rod that goes between the two halfs, this is not leaking when it is running. When I look down from the top of the boat, the water is all going into the lower, so they are working right also.

Bryan

 

[Bondo]

Re: Need help 94 Mercruiser 305

the water is all going into the lower,

Ayuh,..... I've bout Never seen That,......

You should have Water running out the exhaust long before you even turn the Key......

 

[wire2]

Re: Need help 94 Mercruiser 305

I've just this am read the 3 pages in this thread, there's a basic check I'd be inclined to make to isolate the problem into 1 of 2 areas.
Loosen the hose clamp on the hose that supplies the thermostat block and wiggle the hose to break the bond. Idle the engine with muffs on, pull the hose off and verify an adequate volume of water flowing, (I'll guess ~1 quart+ in 5 seconds?) if that looks ok, partially block the hose with a thumb or palm of your hand to verify that there's *some* pressure there.

The missing O-ring mentioned earlier would allow some leakage past the stat, and tend to cool the engine rather than contribute to overheat.

 

[buggiedad_67]

Re: Need help 94 Mercruiser 305

by any chance did you check your water pump belt to see if its tight or slipping

 

[Coors]

Re: Need help 94 Mercruiser 305

Hoses have to be hooked up wrong, if thu-hulls not blowing out water.