Universal engine expert? -M18

[Skipper]

Howdy,

Went to change out the dipstick tube. It has rusted plenty from a long-term drip from the raw water pump. I've replaced the water pump, but the rust didn't go away

So, I back out the screw holding the top of the dipstick tube (not the base), and it just keeps coming out. So much so, that I'm afraid it's attached to something else inside. I pulled it out an inch and a half after the threads let go. Why would a screw holding a tiny mount-flange go 2 inches into the motor? I looked at the tech manual, and none of the drawings show the screw.

Anyway, I screwed it back in, instead of removing it. It's just my luck that there would be a booby trap, and some mechanism would drop into the oil pan or be otherwise rendered inop.

Anyone ever replace the dipstick tube on an M-18, M-12, etc?

Thank you

 

[Skipper]

btw, it's the dipstick type where the top comes to the front of the motor, not the side.

 

[Tim R.]

You are likely safe from something being attached on the inside of the engine. Engines generally are not built that way. I would guess that is one of the bolts attaching your intake or exhaust manifold. I forget which side of the engine the dipstick tube is mounted. You should see many other bolts on that side of the engine at a similar level. Should not be a problem to remove and reinstall when the engine is cool. Just make sure you properly torque that bolt to the manufacturers specs.

All of the engines I have seen online show hte dipstick tube on the side.

Just read your follow-up. Send a picture if you can. Could be mounted with one of the water pump bolts.

 

[Skipper]

Thanks, Tim.

I've attached pictures. One is of an M-18 in a Tartan, which has a similar setup to mine, except the Tartan has full frontal access; mine is partial to port. Side note: The front-mounted setup is hugely better for checking the oil. The side-mounted version would require my climbing into the cockpit locker, after removing the engine side panels, and any stuff in the locker.

In the picture, you can barely see the dipstick ring just to the upper left of the raw water pump. The other pic is a drawing that shows the side of the engine an the tube running forward.

 

[Tim R.]

The bolt is clearly going thru another component before hitting the block. What is that component? Maybe the injection pump? The photos help but we really need a detailed close up of the actual bolt and where it bolts thru the other component.