QuestionQUESTION: Friend is working on Cm400E,On the bottom side of the cylinder on left side their is Groves cut in from timing chain to center head bolt holes , This is on front an rear head bolt holes only on left side ,If you was to look in the front center of cylinder it is open from front to rear ,If you was to stick something in their it would hit the head bolt area this is from the out side ,So if this open to the air and the timing chain area has a grove to this same bolt , Then the oil is going to blow out this grove an run out front an rear of engine .The cylinder to lower crank case gasket doesn't go in this grove , Looked on Micro fish and don't See anything that would go there, Called Honda ,They had No Answer.Engine isn't burning oil it's just leaking out front and rear same side as grove only .Center bolt area only.I also Looked on EBAY at used cylinders and they have same groves ,Maybe You can answer
ANSWER: It sounds like someone has run the engine with a realy loose camchain (either not adjusted or badly stretched) and the camchain has worn through from the camchain tunnel (square hole between the cylinders) and the outside.
The grooves that are worn through are not normal and wouldn't be sealed by any gasket or seal.
A really good welder might be able to TIG weld it to fll the grooves, but replacing the cylinder block is probably a better option.
There's one on Ebay right now (Item number: 350157853715) that looks OK in the pic, but I would call around to the wreckers first - if you can pick it up yourself you can make sure it's OK before you pay for it.
You must be in Canada if you called Honda Canada. If you are in central Ontario, Peterborough Cycle Salvage is one of the best.
Make sure you replace the camchain and the tensioner & guide blades and adjust the new camchain properly to prevent the same thing from happening again.
---------- FOLLOW-UP ----------
QUESTION: It's not the timing chain, If you look at the bottom side the gasket area on left side you cam see two little groves factory cut in the cylinder from bolt to timing chain area ,It's the lower cylinder gasket area,You have to look at the cylinder bottom on left side look really good and you should see what I'm talking about .And I live in USA in Florida called Factory Honda dealer here ,I think it looks like their should be a O ring their,That would go around both of the center cylinder bolts on left side kick stand side,It would have to go under cylinder to block gasket only on left side Their's no groves on right ,I think You are talking about a different area then Me ,It's Got Me lost,I have no answer to why Honda would have made them groves .I hope You can see the groves I'm talking about ,Good answer But that's not the problem it's not something that was worn through .It's factory grooved ,I just can't see any reason for it .Thanks for trying to help
AnswerSorry. I was pretty tired last night and I was sure I read "Honda Canada".
I don't know if I can help you. I have never worked on one of these bikes and I don't have any pics of what the head should look like.
Please feel free to ask someone else.
