Finished with build

[hondaREX]

Finally got all my parts and was able to put the bike back together. Was working on it till 330am but thats the only time when the kid isnt running the show. I didnt have time for a picture build or any in depth one but ill rattle off what i did and how it went. Ill try to post some pics of the bike tomorrow.

Dropped my cylinder off to BCS Performance for a Wiseco 11:1 407cc bore. While they had that i found that one of my exhaust valves wasnt seating right after a hand lapping so i dropped the head off to BCS as well for a SERDI 5 angle valve job. Took them awhile but im not holding it against them, they have a very successful race team and that takes up all their time. But i got it all back and it looked awesome. Replaced the valve springs, stem seals, and the 2 exhaust valves.

I also replaced the cam chain with the CRF450 chain. Installed a HC Stage 2 while i was in there. I did notice, unless i bagged it wrong, that the half sealed cam bearing was reverse of what it should be, but i also noticed that the manual showed it reversed as well. So i put it in the right way when i re-assembled.

I had a full Hinson 8 plate clutch setup and Hinson quick change cover. I mocked up the whole thing in both the Hinson quick change cover with modded XR400 cover and the stock EX cover to see if both fit and operated correctly. They both worked perfect. I ended up only using the stock EX cover though. The 8 plate was bought used so im unsure of the brand. I have a brand new Sparks 8 plate set so i used that set of springs and left the new clutches for the future. Using Rotella 15W-40 now.

I got a sweet full Sparks X6 in the fall. Packing a little blown out but useable. Mounted up nice.

Swapped in my TRX250r rear brake setup. Used the 250r caliper, bracket, and rotor and hub. 400EX locknut, axle and carrier were used. All mounted up and functions perfect. Also added a SS line. Changed gearing to 15/36.

Many years ago when i built my 250r, i picked up a set of EX front hubs that had aluminum spindle nut covers. So i threw them on my current hubs. New Pro Armor chassis skid. Great fit and mounting.

While in the engine i did all necessary gasket and seals. Cometic MLS top end gaskets. Cam chain tensioner and guides all looked and functioned perfect so i left them alone.

So i broke it in today. Slight warm up and i was off. 20 or so minute beating and i changed the oil. Even tipped the bike to drain the lower end real well. Filled it and was back on the trail. MAN....what a sweet sounding exhaust. I wish i had the patience to install one go-fast part at a time so i could comment on each as i went along but that just doesnt happen. But with the exhaust, cam, HI comp piston and 450r carb, it is a new animal. Initial jetting in the 450r is 180 main, 50 pilot, 3rd clip on needle. I couldnt seem to get a stumble out of WOT but i was focusing on hard accel and decels in 3rd and 4th in trails. Im going to put a 182 in and see if it stumbles. But it ran great. Pilot seems pretty close and main is nice but i want it to stumble so i can go down from there.

Overall, the build was a success. Not sure on the gearing yet. Clutch was nice, again was focusing on some things and not others so ill try to pay attention to more tomorrow when i actually go for a ride. Exhaust is awesome!!! Not sure i can keep it as loud as it is but we'll see. Didnt do HD studs so fingers are crossed. Hope you like even though its not a picture build!!

[Blodg]

Awesome! Sounds like we got our quads running on the same day man. Our builds are similar but I guess most people build them about the same way. I will be curious with your temp dipstick how your oil temp is now versus when it was stock. I went to a cooler spark plug on my build, it didn't seem to run too hot today and I will get some temp readings with an IR gun in the next few weeks. I did notice more vibration when revving it while sitting still in my 416, it was not noticeable when riding it though.

I like the 250R rear shock conversion. I spent enough on mine this year but on my list for next winter is to do a 450R brake conversion. But after reading your info maybe I will consider doing a 250R rear brake instead. And the fact that I have a 250R makes that option more attractive as I could swap parts between them if I had to when something broke. Also on my list for next year is maybe a spal fan, I am going to play with the temp gun and monitor my temps this summer and try to decide if I think it will be worth it.

I rode mine for about an hour in two 30 min sessions before I changed the oil. I wanted to ride it hard for break in like as in the "motorman" method and that was not a problem! It was a blast hammering it and feeling the new power and not to mention it was my first time riding a quad since Nov or Dec of last year.

Thanks for the update on all the work you did, I can definitely relate. Keep us updated on how she is running.