400ex Remodel

[hondarider95]

I started tearing down the engine. I got the head off, and will finish the tear down tomorrow, and take the necessary measurements so I can order my piston,rings, cam chain, and a gasket kit. There is some black stuff on top of the piston(see pictures), is that normal?

Does this look like a good cam chain to get?
http://cgi.ebay.com/ebaymotors/Honda-400EX-Heavy-Duty-Cam-Chain-Timing-Chain-BRAND-NEW_W0QQcmdZViewItemQQcategoryZ43977QQihZ007QQitemZ170071871327QQrdZ1QQsspagenameZWDVW

Also will it it be difficult to get the timing correct again? How will this be done?

I finally got some pictures up. Here they are:







Also how many cans of primer, paint, and clear coat should I need to paint the frame/sub-frame and a-arms?

I will keep you all updated on the project.

[Mrs.Nightbreed]

All I see are red X's.

That link is a CRF450 timing chain. You can buy them from anyone that sells Honda parts. We put them in all the 400EX's that we  rebuild.

Did you take pictures of the sides of your piston and inside the cylinder?

[hondarider95]

So I can use the timing chain that is in that link? Is that better to use than a stock 400ex timing chain? I have not pule the piston from the cylinder yet. I will do that tonight and get some more pics up asap. What do you mean red x's? You cant see the pictures?

[hondarider95]

Do I need to measure anything before I pull the cylinder? Or should I go ahead and pull the cylinder out?

[hondarider95]

Ok, I pulled the cylinder and piston. Now what? What do I need to measure? The cylinder wall looks smooth as you can see in the pic below. Let me know what to do next asap, so I can get these parts ordered tonight.

Here's the pics:





Thanks

[Mrs.Nightbreed]

I can't see any of your pics or I could help you....

[klutchbuster400]

Email them to z400warrior@yahoo.com

[hondarider95]

pics sent.

Thanks

[Mrs.Nightbreed]

OK I can see them now. Your cylinder is wore slap out. It should not look like a mirror like that. It needs bored out to a 406 or at the very least it needs honed to get your crosshatch back. I need to see the intake and exhaust side of the piston, but judging from the cylinder I would get a new piston too. The best you could hope for is putting new rings on it, but you are better off replacing it.

What area are you in?

[hondarider95]

How come the engine runs fine, does that maybe mean all I need is a hone. Were can I get a hone or bore? How much is it usually? I want to get everything ordered soon so I can get her up and running asap. I am in Montverde, its near Clermont, which is just outside of Orlando.

[jocolo]

honning tool $30 at autozone

[PREDOCROSS]

Get yourself a shop manual and take your cylinder to a good dealer. They will measure the cylinder and tell you what size piston and rings to order. They will also rebore and hone the cylinder for you. At this point you don't want to do a half way job or you will be just throwing money away. The shop manual will answer all those questions like timing and torque specs. It also shows pictures of how things are supposed to look. Trust me, you will kick yourself if you try too hard to save money or time and end up doing a poor job. However, do it right and you will know more about small engines than 90% of the people around you.

[gery350]

dont know what the tolerance is. you can check it with a micrometer or another rule of thumb is to put a piston ring in the cylinder and measure the gap at the ends of the piston ring with a feeler gauge. im not sure what the tolerance is though.
good luck.

the nightbreeds are good people. i would take their advice.

[xr100racer]

put a piston ring in the cylinder and measure the gap at the ends of the piston ring with a feeler gauge.

Yes, put a compression ring in there and square it up with the piston so it sits even, then find the gap with a feeler gauge. I have not seen any pictures but from what nightbreed said you wont have to do that if your just getting a new piston and bore. Also, I wouldnt try and hone it yourself, the machine shop will do that for you when you get the sleeve borred.

[xr100racer]

You will need to gap your new rings for your new piston, that can be done by using the method mentioned above. The rings will come tight so you will need to measure them and file them down untill you get the desired gap.

[hondarider95]

I have about a 1mm gap and it says the service limit is .5mm. I would think the worn rings would cause most of that gap. I think the new piston and rings shold make up for this right? Let me know what you all think.

Thanks

[gery350]

im not sure but more then likely you will be ok.
i guess youd have to check it with the new rings.
at least you know your on the right trak.

[klutchbuster400]

For those who cant view them

[klutchbuster400]

whoops bit too small, im resizing right now.

[klutchbuster400]

[klutchbuster400]

[hondarider95]

Thanks klutchbuster. I just got a new computer and haven't gotten photoshop yet.

[klutchbuster400]

[exrider]

#1 you need to buy a service manual. Next you need to mic the cyl to check if it is within specs"THE PICTURE'S DONT SHOW ANY DAMAGE " Make sure you take 4 sep. readings,one on each side by the wrist pins, the other two 90 deg from them.If this is beyond your exper. a machine shop is your best bet. Only then can you decide what your next step should be. 

[hondarider95]

Ok, I got a service manual, well the pdf anyway. How do I mic the cylinder? What tools do I need and where can they be found?

Thanks