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RKDad

2003 400EX custom

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oh i was looking forward to a new treasure ..... you seam like a fellah who can take a joke, but i have to say this build will impress me, (I'm  tuned in! ) i reckon shade holds the book on located hacks and mistreated bikes .. some he's chose to rebuild have been for the book, but he's always pulled them back.... 

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I'm going to give it my best. I've built plenty of motors in my day but this will be my first complete bike rebuild. 

 

RK

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Anyone happen to known what the stock cam chain length is and the service limit? I can't find anything in the repair manual at all on cam chain other than the tensioner. I want to check mine to see if it's even worth keeping as a spare.

 

Thanks

RK

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3 hours ago, RKDad said:

Anyone happen to known what the stock cam chain length is and the service limit? I can't find anything in the repair manual at all on cam chain other than the tensioner. I want to check mine to see if it's even worth keeping as a spare.

 

Thanks

RK

Nope they dont have measurements or spec's anywhere. If you go to the crf450r timing chain you will never need another one. Believe me it will be the last timing chain it will ever need. But if you are dead set on measurements i would measure the new one you get and compare them.

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That figures, every other bike I have has it but this one. Oh well, I took your advise as soon as you posted that number I had it ordered,,👍 I think brakes will be next after I find a new steering shaft, I don't like the tilt and twist version I have now. Had a ! of a time getting the tank and plastic out from under it. I had read that a lot of stuff swaps over from the 450. Good to know.

 

RK

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4 minutes ago, RKDad said:

That figures, every other bike I have has it but this one. Oh well, I took your advise as soon as you posted that number I had it ordered,,👍 I think brakes will be next after I find a new steering shaft, I don't like the tilt and twist version I have now. Had a ! of a time getting the tank and plastic out from under it. I had read that a lot of stuff swaps over from the 450. Good to know.

 

RK

LoL. Yeah i have just about everything you can put on a 400ex from a 450. All my brakes front and rear are all 450r. The master cylinders and everything. Im running a yfz450r carb. My nerf bars are designed for a 450r. Axle and swing arm are 450r. My hood is 450r. I have a custom subframe that is made to work with 450r grab bars. The list goes on and on haha

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Hello Ranger, I had a question regarding the cam chain upgrade. Does it work with the stock chain guides? I keep finding mixed reviews on weather they need replacing. Pretty sure some of them didn't have the proper guides to begin with.

 

So I have a few updates, I went ahead and ordered this top end kit, I ordered this because it has what I hope is the Wiseco piston and rings. That's what I was going to use anyway. It states that it's 11:1 comp ratio but i doubt that. Probably closer to stock 9:1. Which is fine, I prefer closer to stock for comparison reasons later.

https://www.ebay.com/itm/324427778436

 

I got a set of rocker arms and shafts as well. I went with valves from Shindy. They seem to have great reviews so why not. Only around $50 for all 4. I haven't decided if I'm going to reuse the valve springs, they are all .12- .18 above the service limit. I'm considering my ridding style and age. I like to rip but rarely if ever rap the motor out on any of my bikes. But I do have kids that are, well, kids. They like to go fast. Maybe keep for a good spare set. 

 

I also got a moose gasket set on the way. Hopefully by the end of next week I'll have enough tools and parts to reassemble bottom end. Crank is back and looks awesome. I thought they were putting roller bearings for the wrist pin but just got a brass sleeve. I could be wrong, I've searched so much stuff it's becoming a blurr at times. 

 

Thanks

RK

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2 hours ago, RKDad said:

Hello Ranger, I had a question regarding the cam chain upgrade. Does it work with the stock chain guides? I keep finding mixed reviews on weather they need replacing. Pretty sure some of them didn't have the proper guides to begin with.

 

So I have a few updates, I went ahead and ordered this top end kit, I ordered this because it has what I hope is the Wiseco piston and rings. That's what I was going to use anyway. It states that it's 11:1 comp ratio but i doubt that. Probably closer to stock 9:1. Which is fine, I prefer closer to stock for comparison reasons later.

https://www.ebay.com/itm/324427778436

 

I got a set of rocker arms and shafts as well. I went with valves from Shindy. They seem to have great reviews so why not. Only around $50 for all 4. I haven't decided if I'm going to reuse the valve springs, they are all .12- .18 above the service limit. I'm considering my ridding style and age. I like to rip but rarely if ever rap the motor out on any of my bikes. But I do have kids that are, well, kids. They like to go fast. Maybe keep for a good spare set. 

 

I also got a moose gasket set on the way. Hopefully by the end of next week I'll have enough tools and parts to reassemble bottom end. Crank is back and looks awesome. I thought they were putting roller bearings for the wrist pin but just got a brass sleeve. I could be wrong, I've searched so much stuff it's becoming a blurr at times. 

 

Thanks

RK

Yes stock guides work perfectly fine. The chain actually fits tight between the side walls and i have been running one in my quad for 5 years with 2 rebuilds for power upgrades between. Have checked guides both times for any wear and they are like new. As for the crank wrist pin having a roller bearing. I think years ago gt thunder and poweroll were doing that upgrade. But all stock and aftermarket cranks and rods for this quad made today do not. Just a brass bushing. It is a constantly oiled bushing though so as long as the oil hole up the rod doesnt clog up it should have no issues from that area. Most used quads sold today have been rode hard and put up wet. And ran out of oil many many times. Luckily this particular quad can handle that for a good long while before getting real bad.

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No doubt about low oil damage. This had less than a quart when I drained it and it was like maple syrup as well. Good to hear on the guides. Mine are like new as well. I thought for sure the knock was as you mentioned, from cam chain slap. Turned out to be low oil burned the wrist pin and the piston was dancing away in the cylinder. Still can't believe it ran, for about .2 sec. Fast as I could turn it off. Hey at least I got one and I don't mind working on them at all. 

 

Thanks,

RK

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1 hour ago, RKDad said:

No doubt about low oil damage. This had less than a quart when I drained it and it was like maple syrup as well. Good to hear on the guides. Mine are like new as well. I thought for sure the knock was as you mentioned, from cam chain slap. Turned out to be low oil burned the wrist pin and the piston was dancing away in the cylinder. Still can't believe it ran, for about .2 sec. Fast as I could turn it off. Hey at least I got one and I don't mind working on them at all. 

 

Thanks,

RK

No problem! Always glad to help! One last thing i noticed. Dont use that head gasket that comes with that niche kit. Those gaskets are junk. Go with a MLS gasket of any kind. I prefer cometic myself. But i know that there are a few other options of MLS gaskets out there. Factory honda would have even been MLS. But you cant do a big bore kit with oem. I wanna say Vertex was one of the others. And maybe wiseco.

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