Help! Stuck 400EX Jug!

[TheDocs400ex]

Hey,

Im new to this forum although I have gotten alot of of useful info from here, but first time to post.

Recently I started taking my top end apart due to some oil burning. Started out not so bad then quickly became worse. Well I have been following the Clymers manual which is a the best $30 ive ever spent and everything has been going smooth but then the cylinder is stuck and i cant get it to budge for anything. What do you guys suggest?

Thanks in advance!

Also when it started smoking it was continuous and didnt stop, any suggestions on what it might be. It started not long after i crossed a creek but it never died, but i do run with no airbox lid, could water getting in the carb cause this?

[honda400ex2003]

rings are usually bad if it smokes all the time. so a hone at the very least is in order with some new rings. Im not sure if water getting in there could cause it but a very hot engine that hits cold water can warp and cause issues such as this. make sure all nuts and such are loose on the cylinder to get it loose. otherwise you can try to tap around the cylinder lightly with a rubber mallet to help loosen it up. steve

[TheDocs400ex]

Well my intentions are the have it bored to a 416 wiseco with hotcams stage 2, crf450 cam chain, and gt thunder hd head studs. I hear that's the best bore for the 400ex and to keep the reliability. What about penetrating oil or wd40 around the joint where its connected?? Would this or could this cause some damage to the motor?

[honda400ex2003]

that shouldnt hurt it any, give it a shot. steve

[TheDocs400ex]

Thanks!

One last question, with a wiseco 11:1 416 piston and a hotcams stage 2 cam, are hd head studs necessary? I hear they are and I hear they arent. I also hear that wiseco pistons arent actually the full compresaion and the hotcam will lower the compression, so yes or no? Also I plan on getting the Cometic EST gaskets, will this eliminate the need for hd studs?

[honda400ex2003]

imo they arent really. your setup will be good to go. you will def enjoy the machine with all of that on it. steve

[honda400ex2003]

imo they arent really. your setup will be good to go. you will def enjoy the machine with all of that on it. steve

[fauxamish]

I am currently running the same setup as you (11:1 416, etc) and don't have HD head studs. You should be fine.

As for the stuck jug, I had the same problem the first time I took mine apart. Try tapping all around the jug with a soft mallet or deadblow hammer. Make sure the 2 small bolts on the cam chain side are removed. If you still can't get it off, try using a pry bar and GENTLY tap on it to try an pop the jug up. I had to do this and just kept rotating around the jug and very gently tapping and prying it up. Eventually the gasket let go and I could take the jug out.

[fmftrx300ex]

you dont need the studs but if u plan on going for higher compression in the future it couldnt hurt to do it now

[TheDocs400ex]

Thanks for all the info guys!

What about a cam chain? I believe mines was slapping, or at least i was hearing a ticking noise from the right side of the motor ( the noise got louder the longer I rode it and the sound sped up when i revved it) I know the crf450 cam chains will fit so I plan on picking up one of those. How hard are they to install? I have a Clymer manual and i am pretty mechanically inclined but are there any special tools i need? I know I can look and read the manual all day long but I'd like to get some opinions from people with hands-on experience.

[honda400ex2003]

The chain isnt bad to do, esp with the manual handy. you should have no issues with getting it in there. as a side note, the 02 crf chain will work. steve