Bleed system port differences replacing 210 with a 240

[jjb325i]

Hi.

What engine do I have? Every one I see has these oil ports at the cylinders.

Ive been searching but cant find any info.

I have purchased a used replacement 210 hp(im told) M2 sport jet(no plate on the engine..how do I identify?) which looks almost the same as my blown 210 but is missing the ports on each cylinder and the ports on the reed block are in different locations. I believe its a 240 block and ive swapped out the crank cover/reed holder block and my carburetors but dont know what to do with the hoses .
I am trying to replace the engine, have removed the oil system and am going premix so what do I do with these ports,hoses? are these ports oil or vacuum ?

Also The port on the block that connects to the pulse port on the fuel pump is a smaller port than what was on the 210 HP (3/16 vs 1/4" ?) so the pulse hose on the pump is too large for the block fitting .(option?)
Thanks in advance for your help.

John

 

[Dr Honda]

Post some pics. We can't ID it without seeing it. BUT... the Merc 2.5L engines were almost all the same, and very interchangeable. (even to the outboard engines) so, if there isn't a tag... it will be hard to tell exactly what you have.


The bleed hoses are at places were oil will pool. The system will suck the pooling oil out, and re-introduce it, to be burned. Regardless of if you are going pre-mix... those hoses have to be there.

 

[jjb325i]

Tony,
Thanks for the response. Here nare a couple photos . One of the original 210 and the other the suspected 240?
Note that each cylinder of the 210 has a port where the 240 appers to have one in the middle and when you see the routing it is different . The question is when I mix the Carb of the 210 with the EFI 240 block how do I address the bleed function? Should carbed engines have a port on each cylinder(I hope not)?

Thanks again,

John

John

 

[jjb325i]

sorry about the duplication. Im new to this uploading fiunction

 

[Dr Honda]

They run better when the connecting rod stay in. (sorry, had to be said)


Yes... the second block is an EFI block, or an early carb outboard block. So... if you are going back to a carb engine, using the second block... then just plug off the bleed ports that would have led to the cyl's. Keep the others hooked up.


Basically, the system works via the pressure in the lower half of the case. On the EFI, it pushes the extra fuel/oil into the vapor tank, and the carb version, gets the extra pushed into the bypass ports on the cyl.

 

[jjb325i]

As evidenced by the 10 seconds I heard it run before the birth of the beautiful baby connecting rod.
So the fuel puddles differently on the EFI block. So is that one port, on the 240 EFI engine, where all the fuel puddles? It seems the 240 bleeder routing connects many of the ports together on the carburetor end with one line going back to the block. I was thinking I should try the same or should I block them as you suggest.
Thanks for your continued expertise.
Ill attach a couple more photos you may like.

John

 

[Dr Honda]

I feel your pain. Below is my engine from 7 years ago. I got lucky I guess. My rod came though the bottom half, so I was able to weld it up. The sleeve was busted in the bad cyl... but the block had enough integrity, that I was able to put in a new liner.

The fuel doesn't puddle in different places EFI Vs Carb.... but where they return that fuel to does. On the carb block... you could take the ports that are mid block... put them together on "T-Fittings", and feed them back to the base of the carbs. I guess if you feel brave... you could install the Cyl fittings back into the newer block. Just be carful that you aren't drilling into the water jacket.

 

[jjb325i]

Wow . you were able to salvage that? How could the mercury team approve that plastic gear design? No I am not that brave and will not add the ports. So the puddling oil comes from the cylinders but each cylinder does not require a bleed point? It makes sense to me that each cyl would need one but I dont have a functional understanding of the design. What if the puddling doesnt get routed back to the carburetors or intake? . Does that design provide equal dispensing to each intake point? Why would the 210 have 6 points and the 240 have 1?

Thanks again Tony.

 

[Dr Honda]

The puddle isn't in the cyl.... the puddle is in the block. (around the reeds and the crank seals) It re-injects it into the cyl. With the EFI engine... it's easier to just re-inject it back into the fuel reservoir.


The plastic gear isn't an issue at all. It's just the failure point... like a fuse. (You don't blame the fuse when you have an electrical problem... do you?) Anyway... the gear normally fails because the engine has been overheated multiple times. SO... generally, there is a bigger issue that is being ignored. When the engine overheats, the bushings (bronze bearings) that the long drive gear ride in, will swell. In turn... the metal drive gear binds up... and that takes out the plastic gear. If it was made out of metal... both gears would wear, and fail faster. The plastic holds a little oil, and actually can run longer. (over all life) My engine didn't fail because of the gear. The gear on my blown engine looked brand new. My engine failed because a bolt came out of the connecting rod. (and ate itself) On that note... the new gear in my engine is plastic... but the new style gear is a glass filled plastic, and is much stronger. BUT... if the oil pump binds... it will wipe out the gear regardless of what It's made of.



With that all said... Mercury should be absolutely ashamed of it's decision to remove the pump sensor !!!!!!!!!!!!!! In the earlier engines... they had a sender on the block, that watched the pump for rotation. If it stopped... it would sound an alarm, and (I believe) shut off the engine. The place for the sender is still in the 2.5L blocks... they just didn't machine them open. But lets face it... the electric pump can still fail. (or lose power) Although... they are not known to have an issue.


As a final thought... your gear looks ugly... but it doesn't look like it failed. 2 stroke engines, sometimes just eat themselves. As they wear, the ability for that small amount of oil, that is mixed with the fuel is just unable to keep the parts lubed. OR... the pistons wear, and they crack, and fail. You have to remember... unlike a car engine... a boat engine lives it's entire life in the upper RPM range. I'm guessing 4500 to 5500 rpm is it's normal RPM. In comparison... your car lives most of it's life at 1500 to 2200 rpm. (running down the highway)

Here's the original gear from my engine. As you can see... after 9 years of hard use... it was fine. FYI... my boat came from a rental shop. It had +500 hrs of hard use before I got it. (with the bad engine)