Motor Runs New t-stats but still over heating?

[MercBlackMax1]

Hey everybody!! Now that i figured out that my Foot was the Problem i took it off and put back the heads and water cover wth new gaskets for the head and cover and put in some new t-stats. The motor started up great in the drive way with the garden hose plugged up to the main water line and the tell tale was going. For some reson the !#@?%$#%# still seems to want to over heat went over the 180 f on the gauge so i shut it down Whats going on with this?

I see alot of posts about running lean can cause over heating but im sure i mixed it 50:1 because i have a counter bottle for mixing. I didnt change the poppet valve but it seemed to work great the spring moves up and down no prob!

Anything else to check?

Thanks agin matt

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

Hey everybody!! Now that i figured out that my Foot was the Problem i took it off and put back the heads and water cover wth new gaskets for the head and cover and put in some new t-stats. The motor started up great in the drive way with the garden hose plugged up to the main water line and the tell tale was going. For some reson the !#@?%$#%# still seems to want to over heat went over the 180 f on the gauge so i shut it down Whats going on with this?

I see alot of posts about running lean can cause over heating but im sure i mixed it 50:1 because i have a counter bottle for mixing. I didnt change the poppet valve but it seemed to work great the spring moves up and down no prob!

Anything else to check?

Thanks agin matt

Oh another question maybe water is not getting to the block because im not plugged into the pipe from the bottom and also does the temp gauge plug onto the SENDER ASSY-TEMP or the one thats touching the outside of the cover?

 

[coastalrichard]

Re: Motor Runs New t-stats but still over heating?

Can you remind us what motor you've got...I'm assuming it's a Black Max (my bad, maybe)...but what year and HP?

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

Can you remind us what motor you've got...I'm assuming it's a Black Max (my bad, maybe)...but what year and HP?

soory man guess im getting to comfortable! merc blackmax 200hp year 85

 

[coastalrichard]

Re: Motor Runs New t-stats but still over heating?

I re-read your first post and I'm a bit confused. You say you took the LU off and put the heads, etc back on. What did you do to the LU when you took it off. Replace pump housing, impeller, etc?

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

I re-read your first post and I'm a bit confused. You say you took the LU off and put the heads, etc back on. What did you do to the LU when you took it off. Replace pump housing, impeller, etc?

i busted the gears in the lower unit and i thought i blew the crankshaft. somone suggested taking off the lower unit too see if it was the motor or the LU. i took the heads off to see if i could see damage in the cylinders therefor ruining the gaskets so i replaced them and reassembled the motor.

I thought that i had blown the motor at first because i pinned it and the hole thing seized up and i overheated. I tested the compression with the lower unit off and its good on all cylinders so i rebuilt it back upp and fired it up in the drive way with no Lu on and a garden hose to my water hose.

Motor runs good but it seems to want to get hot again even with water pissing from teltale but maybe my wire to the gauge is in the wrong place i have two places i can put it on the ouside of the block and anothe spot thet goes to the cap on the inside of the block.

 

[oldman570]

Re: Motor Runs New t-stats but still over heating?

Sounds as tho the wire goes to the sender on the outside of the head for head temp gage instead of water temp. Senders have diffrent values of resistance for diffrent gages that has to match up. You probly have a head temp gage.
Oldman570

 

[Faztbullet]

Re: Motor Runs New t-stats but still over heating?

Does your hot horn work? Is it sounding? Have you tested the temp sensors? Throw that %&@3 temp gauge away and install a water pressure gauge as temp gauges are known to cause imaginary problems....

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

Does your hot horn work? Is it sounding? Have you tested the temp sensors? Throw that %&@3 temp gauge away and install a water pressure gauge as temp gauges are known to cause imaginary problems....

hot horn doesnt work i guess never heard it. I have a temp gauge and a psi gauge. the reason i agree with the gauge is cause the heads get to hot to touch,but then again now that i now the foot was the problem the boat worked amazing before i blew the gears up in the foot.

 

[Faztbullet]

Re: Motor Runs New t-stats but still over heating?

The heads will get hot to the touch, should be able to lay hand an it and count one, two and you will have to remove hand. Fix the horn as it will tell you if its hot and whats your water pressure if you have a psi gauge?? Temp gauges are worthless in my opinion as I can make it read cooler by just backing it a turn or two off the cylinder head.

 

[BonairII]

Re: Motor Runs New t-stats but still over heating?

I see alot of posts about running lean can cause over heating but im sure i mixed it 50:1 because i have a counter bottle for mixing.

Having the correct premix doesn't prevent a motor from running lean. You can have the correct amount of oil mixed with gas, but if the carb(or injectors) aren't pumping the correct volume of fuel(premix) into the cylinder....a lean condition exists.

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

The heads will get hot to the touch, should be able to lay hand an it and count one, two and you will have to remove hand. Fix the horn as it will tell you if its hot and whats your water pressure if you have a psi gauge?? Temp gauges are worthless in my opinion as I can make it read cooler by just backing it a turn or two off the cylinder head.

hey thanks where is the horn located in the dash im guessing? doesnt the psi gauge just tell you if you water pump is working. I dunno what the pressure is because i dont have a lower unit on. and i never noticed when i went out with it that one time,

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

Having the correct premix doesn't prevent a motor from running lean. You can have the correct amount of oil mixed with gas, but if the carb(or injectors) aren't pumping the correct volume of fuel(premix) into the cylinder....a lean condition exists.

Wow i hope this isnt the case because that sounds like a tough problem to fix. i took my plugs out after running it for a while and there is a drip of premix on all of them. maybe too much oil?

 

[BonairII]

Re: Motor Runs New t-stats but still over heating?

Too much oil isn't a bad thing(within reason). All it will do is make the motor smoke more.

Very clean carbs go a long way toward preventing a lean condition. Old fuel lines will clog carbs in a hurry.

 

[j_martin]

Re: Motor Runs New t-stats but still over heating?

There should be a bit of unburned oil on the plugs. That's normal.

The phrase "running lean" has nothing to do with the oil-gas mixture. It has to do with the gas-air mixture. In fact, too much oil can cause the gas to flow slower and cause the engine to run lean.

That said, Water delivery and control (t-stats, poppet) has to be right. About the only way I know to sort that all out is with a water pressure gauge. Water temp will vary considerably under different conditions. It isn't like a closed cooling loop automotive engine.

After that, being out of tune, timed significantly late, and on this engine, even overloading by too steep a prop can cause them to run hot. Lean fuel mixture can cause overheat also, although the problem usually will affect only one or 2 cylinders and cause piston damage in those cylinders.

If it seized up when you first blew the LU, the engine is damaged. Overheat can be caused by significant ring leakage, not always detected by a compression test. A leak down test can sort that out.

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

There should be a bit of unburned oil on the plugs. That's normal.

The phrase "running lean" has nothing to do with the oil-gas mixture. It has to do with the gas-air mixture. In fact, too much oil can cause the gas to flow slower and cause the engine to run lean.

That said, Water delivery and control (t-stats, poppet) has to be right. About the only way I know to sort that all out is with a water pressure gauge. Water temp will vary considerably under different conditions. It isn't like a closed cooling loop automotive engine.

After that, being out of tune, timed significantly late, and on this engine, even overloading by too steep a prop can cause them to run hot. Lean fuel mixture can cause overheat also, although the problem usually will affect only one or 2 cylinders and cause piston damage in those cylinders.

If it seized up when you first blew the LU, the engine is damaged. Overheat can be caused by significant ring leakage, not always detected by a compression test. A leak down test can sort that out.

hey thanks for all the help i appreciate it. i took of the air intake just before and everything in the carbs seems spotless im actually suprised at how clean they where.i think im being foold by the gauge but who knows. i dont really have anything to do a leak down test. tommrow im going to stitch my gauge wire to the inside of the block and see if i get a better reading

im also wondering whether i should plug my garden hose on the bottom of the mtor or straight to the hose that goes to the tell tale and t-stats?

 

[aussieflash]

Re: Motor Runs New t-stats but still over heating?

Carbs need to be removed and dismantled for cleaning/inspection and rebuilding.Removing air box and looking down Carb throat will tell you nothing.

 

[MercBlackMax1]

Re: Motor Runs New t-stats but still over heating?

Carbs need to be removed and dismantled for cleaning/inspection and rebuilding.Removing air box and looking down Carb throat will tell you nothing.

i understand that but if i take them off to inspect them i read that i have to rebuild the carb with new everything id be pretty dissapointed if i did that and everything checked out then had to put more $$ and tell the truth im kinda sketched out of playing around in the carbs because its a pretty important part of the motor.

should i buy the seloc manuel.

then id probly stop asking these "stupid" questions
really like this forum though the guys all seem to know what they are talking about.

probly better than the manuel

do you know what the litle hose/tubes are that go all over the motor they are about a 1/4 inch dia and there is about 5 6 of them?

 

[aussieflash]

Re: Motor Runs New t-stats but still over heating?

They are your bleed lines.They recirculate unburnt fuel.
If you can only buy mercury service manual.

 

[j_martin]

Re: Motor Runs New t-stats but still over heating?

I'd use the Seloc manual........ in the back house.

Look up your manual part number in mercury's online parts service by your specific engine and serial number. Then look for one at Amazon or eBay. They're pricey, but you won't be tempted to wipe your ....... with it.

Usually the only things that go wrong in the carbs are gaskets and crud. Other parts, like needle, and float can be inspected and replaced if needed, which would be rare. Gasket kits are about 8 bucks, 3 needed, plus 3 carb base gaskets at about a buck each. You can re-use the horn gaskets, they aren't critical. Spray can carb cleaner is fine for the job.

I just noticed the year of your engine. The original floats might have been foam, and the new fuels sink them. If that's true, find a set of used WHnn carbs off anything V6 from 135 hp up and 1988 or later to get the floats. They are NLA, and I don't think there's enough market for anybody to make aftermarket ones. One company put up a part number, but never actually made any. If your floats are hard plastic, yer golden on that point.

The WH series carbs are very simple. If you pay close attention to details, including torque order on the bowl, you shouldn't have any trouble going through em. Maybe buy an extra gasket set. If you have to go back into a carb after it's torqued, you should replace the gaskets again.

After the carbs are rebuilt, you need to go through the linkage and timing adjustments. It's pretty intimidating for a newcomer, but actually not difficult. There's just a lot of steps that don't make sense until you go through it a couple of times.

You do need to get yourself educated so you can at least identify the parts on the engine.