2003 Challenger 1800 Mercury power head rebuild

[Twtherrien]

Hello All,
So the good news is my buddy got bit by the boat bug, but the bad news is I need some assistance. He found a 2003 challenger 1800 for a great price, but has some damage to the cylinders. I have seen a couple threads on th 240 EFI powerhead rebuild, but If there is anyone who can help us gather some information in order to tackle the rebuild I would appreciate. All I have been able to find is the installation guide for the mercury 200/210/240 jet drive installation manual, but this only covers installation and removal of powerhead. I am looking for the shop manual that details the rebuild of the power head and cylinders. There is a local machine shop that I'm hoping would help if I need to. Thank you all in advance. Also if you know of some good threads on here documenting the process please reference them here.

Thanks!!

 

[Dr Honda]

My thread is about the most complete. (link below) But, there isn't a "Step-by-Step" on a rebuild that I know of. As far as the manual goes... there are Merc Manuals on this site, but you need to be a premium member to access them. I'm not pushing you to become a supporting member, but it does go to keep this site running.

Dr Honda's Islandia Project. (Engine rebuild, and other stuff)

As far as using a local machine shop... unless they are set up for big 2-strokes, they may not be able to help you. These engines are known as "Blind" engine blocks. On a standard engine, and even 2-strokes used on motorcycles, and other watercraft... the cyl is open on both ends. So... when you cut the cyl... or finish it with a hone... you pass the tool though the cyl completely. The bottom of these cyl's are closed with just a slot for the connecting rod. Because of that, standard tooling can't cut all the way down. Also, if they have automated machines, they will just slam the bottom of the engine block. If you have someone with the right knowledge... the right tools... a GOOD CNC machine... a digital probe... and knows how to write a program to compensate for the bottom measurement... they may be able to help. When my shop was open, I would cut Merc blocs for people. Unfortunately, I sold my equipment about 4 years ago.


With that said... if you post questions... I will be happy to give you direction with the project.

 

[Twtherrien]

Thanks Dr. Honda for the info as always. Yeah we understand we need a special ahop. My friend said there is one nearby that has done tons of work on his car block. We are going to do compression test and pull head to assess how bad the damage is. We are hoping they caught it and shut it off with minimal damage. If we think it’s feasible we may tackle it ourselves with a rebuild kit, but trying to do as much research as we can to make sure we do everything right.

On a side note while I have you. I have seen some other threads you are involved in in regards to steering cable. My 2001 utopia is having troubles steering right on plane. Upping investigation the outer flared sleeve has come loose and slides back and forth. Am I correct that you sometimes can pop it back in place. I’m hoping to remove the clip holding the rubber boot slide it back into place and then reclip. Is there a temporary fix I can try or do I need to replace the cable?

 

[Dr Honda]

............. Yeah we understand we need a special shop. My friend said there is one nearby that has done tons of work on his car block.................

That's my point. A shop set up to do car engines won't be able to work on this block. So... before you assume they can... ask if they can do machine work on a "Blind" cyl engine. If they don't understand that question... the answer is NO. AND... DO NOT let them use your engine as a test.

On your cable... if you can push the sleeve in, and it snaps back into place... it may work for a while. OR, if you have enough outer housing of the cable coming out of the hull, you could try to use a chunk of fuel hose, and a couple clamps to hold it in place. But basically, you need a new cable.

 

[Twtherrien]

Just wanted to provide an update. We got power head off. Opened it up to assess the damage. Anyone know if the sleeve can be changed or is it cast around it? It seems like we are going to buy a rebuild powerhead and swap everything over.

 

[Dr Honda]

Since you don't have a hole in the block itself... you are in luck... Yes... the sleeve can be changed. LA Big Bore (LA Sleeve) makes replacement sleeves. They are around $90 last time I checked. If you are brave... you can do it yourself at home. BUT, you will still have to send it to a shop to trim and finish bore.

Yes... that is my home oven being used to change mine. The wife wanted to choke me when I brought the engine into the kitchen. LOL