Top end rebuild has begun!

[Gibson]

I have a few questions. I'm in the process of taking my valve cover off and some of the 8mm bolts are seizing up on me and i'm afraid they're going to break. i've got them far enough out that i couls spray some penetrating oil into the holes. but what should i do if i can't get them out? if i go ahead and try to get them out with a ratchet, they're gonna snap.

[Ruby Soho]

if you got them backed out alittle, spray in some pb blaster, and work them back in, out alittle, back in, out alittle more etc.. itll come out

they are weak bolts though so don't be surprised if they break

[Gibson]

thanks. i finally got them out, i'm gonna get a clymer's manual before i go any farther though. i want to make sure i take it apart right so i dont mess anything up. this is the first four stroke top end i've done.

[blankenship]

yea u dont want to break any of the 8mm bold i have broke 5 of them and found out the hard way its not easy to get the broke bold out i also had to heli coil one of them aswell

[Gibson]

the one that gave me the most trouble almost broke on me, the shank was turning and it finally broke loose. i'm gonna go ahead and take the cam out and take the head off. i'll post some pics later tonight

[Gibson]

alright i tore the whole top end off earlier and was surprised at how clean this motor was to be 11 years old, turns out it had the stock piston in it so the guy we bought it from lied about the high comp. piston. i'm ordering a 11:1 406 complete top end kit in the next couple of days along with a stg. 3 hotcams. Since my dad is helpin pay for this, he's orderin what he wants.

http://i276.photobucket.com/albums/kk34/crg10493/100_1186.jpg

http://i276.photobucket.com/albums/kk34/crg10493/100_1200.jpg

http://i276.photobucket.com/albums/kk34/crg10493/100_1193.jpg

small ring groove and some scoring
http://i276.photobucket.com/albums/kk34/crg10493/100_1187.jpg

its hard to tell, but the cam bearing spun in the valve cover, is this ok?
http://i276.photobucket.com/albums/kk34/crg10493/100_1201.jpg

that's all for now, should have some pics later this week, next week is spring break so i'll have the whole week to break it in if we get it finished in time. Have any questions or suggestions let me know. jacob

[matt14c]

The stage 3 cam is really drastic for a 406. You may want to look more into that.

[Gibson]

Originally posted by matt14c
The stage 3 cam is really drastic for a 406. You may want to look more into that.

i like mid-top end power, and i don't need a lot of bottom end on most of the trails i ride. i dont think the stg. 3 will take all of the bottom end away either. but that's what my dad said he wants to put in it, i'm not arguing with him cause i'm finally gettin my motor rebuilt:D

[brian76708]

Originally posted by Gibson
i like mid-top end power, and i don't need a lot of bottom end on most of the trails i ride. i dont think the stg. 3 will take all of the bottom end away either. but that's what my dad said he wants to put in it, i'm not arguing with him cause i'm finally gettin my motor rebuilt:D

my stg 2 took away from my bottom end if i was to do it again i would have gotten the stg 1. so the stg 3 is def gonna take away your bottom.

[Gibson]

i'm still wanting to try it. i have gobs of bottom end so i don't think it will hurt to lose just a little bit. i'm going with a bigger bore in the future so that'll give some of my bottom end back

where you getting the 406 11 to 1 kit?

[Gibson]

Originally posted by SuicideMFNdoors
where you getting the 406 11 to 1 kit?

look on ebay, it's a whole top end kit, comes with every gasket and o-ring, valve seals, and piston for like 180 bucks

[dariusld]

Replace these bolts.

[brian76708]

Originally posted by dariusld
Replace these bolts.

may i ask why i just put locktite on them

[dariusld]

When I first rebuilt mine those two bolts backed out, even with loctite.Luckily there was no damage. I replaced them with new ones, and its been fine since. I don't know why it happened,but I should of replaced them the first time.

[F-16Guy]

Originally posted by brian76708
may i ask why i just put locktite on them
I was wondering the same thing. Just clean everything well and use thread locking compound (and a torque wrench if you have one).

[scuzz]

Originally posted by F-16Guy
I was wondering the same thing. Just clean everything well and use thread locking compound (and a torque wrench if you have one).

Man if you (the proverbial you, not you F-16) put a motor back together without a torque wrench you're really asking for problems later.

[Gibson]

i don't see any need in replacing those bolts, just use loctite and a torque wrench. i talked my dad into getting a stg. 2 hotcam this morning. we found a brand new stg. 2 for 125 bucks on ebay last night, i'll probably order it when i get home today

[F-16Guy]

Originally posted by scuzz
Man if you (the proverbial you, not you F-16) put a motor back together without a torque wrench you're really asking for problems later.
I totally agree, but I know it happens.

[F-16Guy]

Originally posted by Gibson
i don't see any need in replacing those bolts, just use loctite and a torque wrench. i talked my dad into getting a stg. 2 hotcam this morning. we found a brand new stg. 2 for 125 bucks on ebay last night, i'll probably order it when i get home today
I think that will be a good choice. There is such a thing as too much lift and duration for any given engine combo, and with the mods you're going to have, I think a stage 2 HotCams or similar cam will be plenty. The 400ex engine will never rev like a 450r, so, IMO, I think it's better to take advantage of the awesome bottom and mid it has to offer.

[Gibson]

here's the top end kit i ordered earlier
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=400039109978

I'll order the cam probably today. My dad called the local machine shop and it's $50 for a cylinder bore, and $50 for head work (ground valve seats, valve guides, valves/springs) We're taking the head and jug to them as soon as my piston comes in. I'm hopin to have this together by next week

Originally posted by Gibson
look on ebay, it's a whole top end kit, comes with every gasket and o-ring, valve seals, and piston for like 180 bucks

sounds like a pretty good deal

[Gibson]

Originally posted by SuicideMFNdoors
sounds like a pretty good deal

we called the local cycle shop and it was gonna be $265 for them to order the same kit.

[Gibson]

My piston kit came in today. We're taking it to the cycle shop tomorrow. I finally get to order my cam and CRF timing chain tomorrow since we'll have money in the bank.

http://i276.photobucket.com/albums/kk34/crg10493/100_1203.jpg

hopefully i'll have it together by the end of the week

[Gibson]

The cycle shop said it'll be monday before they start working on my cylinder and head. So i was bored earlier and started painting stuff. here's what i've done so far

http://i276.photobucket.com/albums/kk34/crg10493/100_1212.jpg

[Gibson]

well, this has been the longest week of my life, lol. I called the cycle shop earlier today and they said everything would be ready to pick up in the morning. My Hotcam came in this morning, so as soon as i get my cylinder and head i'm gonna put it back together. I'm hoping to have it together and running by tomorrow afternoon, i'll post a sound-clip when i get it runnin.:D

[F-16Guy]

Don't rush it. Here are a few things to do/check during assembly:

Use a TORQUE WRENCH (inch/pound scale) during assembly!! Especially for head and cylinder bolts/nuts.

Stuff rags around the connecting rod and crank assembly so nothing can fall down into the bottom end. Nothing sucks worse than that.

Ring end gap -- Follow the directions that came with the rings. Carefully slide one of the top rings down about 1/4 way into the cylinder and use the piston to square it up. Use a feeler gage to measure the gap and ensure that it's within limits (usually about .004" per inch of bore, so about .012" as a rough guide, but follow the manufacturer's specs if different). If the gap is too tight, carefully file a SMALL amount of material from the end of the ring and remove any burrs or rough edges with fine emory cloth or sandpaper. Repeat until the gap is within limits. Repeat with second ring. Don't gap the oil rings.

Gasket surfaces -- I like to use a straight edge razor, a small wire brush, and some solvent (MEK, isopropyl alcohol, etc.). Make sure the gasket surfaces are as clean as possible. Prep like this makes all the difference.

Installing the piston -- Buy a cheap ring compressor from your local auto parts store. Install the rings onto the piston, making sure you stagger them according to instructions. Install one of the circlips into one side of the piston's wristpin hole. Oil up the sleeve, piston, and ring compressor with a light coat of motor oil. Use the ring compressor to install the piston into the bottom of the sleeve just far enough so that the rings are in but the wristpin hole is accessible. Ensure that the base gasket is in place on the engine case. With a helper, hold the cylinder/piston over the connecting rod, line up the wristpin hole with the connecting rod hole, and insert the wristpin in the side of the piston that doesn't have the circlip. Slide the wristpin all the way in against the pre-installed circlip, and then install the remaining circlip. Ensure that the cam chain gets fished up through the cylinder and any rags are removed from around the rod, and then lower the cylinder assembly down to the case and ensure that the piston moves smoothly in the bore.

Cam timing -- Once the cylinder is bolted to the case and the head is bolted to the cylinder, you'll want to rotate the crank CCW until you line up the "T" mark in the timing window on the stator cover. With the "T" mark lined up, the cam will be installed properly when the lobes face down toward the head and the cam gear has two lines parallel with the gasket surface and the third pointing up. Don't forget to coat the cam and rockers with assembly lube. Also ensure that the cam bearing with the seal is on the right side of the engine with the seal facing out toward the right side of the engine. That seal creates a little reservoir and forces the engine oil through the cam journals. That's very important to get right, because it could cost you a cam and rockers, or even a whole head.

Cam break-in -- Get your carb jetted close before your first start up. I would stay on the rich side with a 42 pilot and a 165-170 main for the first start. Don't worry about the piston while breaking in the cam, it will be fine. Start the quad and as immediately as possible bring the RPMs up above about 2,000. Don't let it idle for the first 20 minutes!! Check for leaks or other problems. If there are no problems, and if you can, ride the quad around easily for about 20 minutes, keeping the revs above 2,000 and avoid lugging or over-revving the engine. If you don't have a place to ride, try to break in the cam outside and/or with a fan in front of the engine to keep it cool. Things will be tight at first, so it will run hotter than usual until it breaks in a little. Once the cam is properly broken in, just ride normally (but not too hard) for the first tank or two, and it should be ready to rip. At that point, lean the jetting out and have fun.

[Gibson]

THANKS! that was the kinda reply i was looking for. I didn't plan on rushing cause i know something will get forgotten. I DO have a few questions though.

1-what if my jetting was just a little on the rich side to begin with? will i still have to rejet it?

2-What type of oil should i use to break it in? Conventional or synthetic?

3-After the cam break-in, how fast can i get it? about 1/2 throttle?

[Gibson]

oh, i'm pissed off now! :mad: the idiots at the cycle shop messed up the bore and they had to bore it out to a 416, and idk if they even ordered a 11:1. So now its gonna be another day or two before i can get my stuff back. I'll be glad when i get my own equipment and can do this on my own and do it RIGHT.

[F-16Guy]

Originally posted by Gibson
THANKS! that was the kinda reply i was looking for. I didn't plan on rushing cause i know something will get forgotten. I DO have a few questions though.

1-what if my jetting was just a little on the rich side to begin with? will i still have to rejet it?

2-What type of oil should i use to break it in? Conventional or synthetic?

3-After the cam break-in, how fast can i get it? about 1/2 throttle?

1- A stock engine and one with a high compression piston and cam are going to require much different jetting. Do you know what's in there right now? If it's not at least a 162 main and a 40 pilot, I wouldn't even try it. Just spend the $10 on the right jets and be done with it. That's somewhere you don't want to skimp.

2- Conventional. Most people agree that synthetic is too slick for the engine to break in properly. You actually want a certain amount of friction during break-in so that the parts can mate together properly. I would run at least a few tanks through it before thinking about going synthetic. I've run my 416 solely on conventional oil and never had a problem. My top end is several years old and still very strong.

3- After the cam break-in is done, I would go easy at first (no WOT for longer than a couple seconds, no hard acceleration, no lugging, etc.) and then ride progressively harder as you burn through the first couple tanks. By the end of the second tank, it should be pretty much broken in and ready for an oil change and jetting.

[F-16Guy]

Originally posted by Gibson
oh, i'm pissed off now! :mad: the idiots at the cycle shop messed up the bore and they had to bore it out to a 416, and idk if they even ordered a 11:1. So now its gonna be another day or two before i can get my stuff back. I'll be glad when i get my own equipment and can do this on my own and do it RIGHT.
You'd better call them and make sure they're getting you exactly what you want. If you don't, and you end up with the wrong piston in there, you'll only have yourself to blame.
Did you have the first piston (406) with the cylinder when you took it to them to have it bored? How did they mess it up?

[Gibson]

yea we took the piston when we took the cylinder. The boring bit broke while they were boring my cylinder (just my luck). We called them back earlier and they ordered a 11:1 87mm(416) piston. so everything is fine but i'm still aggravated cause i have to wait longer. They better not try to charge us extra for their mistake.

[F-16Guy]

It sounds like an honest mistake. Things break sometimes, and there's not much you can do about that. As long as they don't try to charge you more, then I would call it good. It sucks having to wait, but you could take the extra time to organize and clean things to get ready for assembly. What gasket set did you get? Cometic?

[Gibson]

I'm calmed down now, it was just the fact i have to wait longer. i've been cleaning and organizing things on it. i stripped the paint off my clutch & stator cover, and painted several engine parts. I think the gasket kit is factory honda, the head gasket has factory part numbers on it.

[cam19aro86]

Well I figured I would throw my 2 cents in. Definately use a torque wrench on putting your motor together. You can get one at sears for $30 and it will save you the heart ache. Second, those cam cover bolts... get new grade 8 bolts the same size-they are junk. The manual tells you 10 ft. lbs. for these bolts, they will break before you ever get there. It's about another $20 investment and well worth it. I would replace them so next time you rebuild the old girl you don't have to get your jug drilled and tapped. If you don't get new bolts just don't try to get 10 ft. lbs out of them, they will snap I can almost promise you. Just tighten them until they are snug.

[Gibson]

my dad has a Snap-on digital torque wrench that reads in inch lbs., foot lbs., and newtons so we're all good:D. i'm gonna reuse my valve cover bolts, just put a little anti-seize on the threads. i went to the cycle shop to look at my cylinder and it isn't messed up bad, but it needs to be bored out for sure. They're not charging us any extra, cause it was their mistake. so while i have to wait another week, i'm re-painting alot of stuff on my quad.

[justin1022]

dude you should be happy you went with the stage 2 cam and not the stage 3. the stage 3 is for strokers. and for jetting my quad has a stage 2 came 440 12.5:1 big bore kit a hd timing chain hmf pipe stage 2 rev box and a few little other things and i run a 180 in it. so you should probably need like a 165 ish.

[Gibson]

well, everything is finally coming together after two and a half weeks:ermm: i picked up my cylinder and piston today and my head will be done tomorrow. Turns out my intake valves were shot, the edges were sharp as razors. i got as far as i could today. so by tomorrow afternoon, it will be running:D

here's a few pics of my progress....
http://i276.photobucket.com/albums/kk34/crg10493/100_1228.jpg
http://i276.photobucket.com/albums/kk34/crg10493/100_1231.jpg
http://i276.photobucket.com/albums/kk34/crg10493/100_1229.jpg
http://i276.photobucket.com/albums/kk34/crg10493/100_1230.jpg
^^still a little paint left on the cover but i'll get that off with steel wool.
http://i276.photobucket.com/albums/kk34/crg10493/100_1234.jpg
^^endcap i made for my e-series
http://i276.photobucket.com/albums/kk34/crg10493/100_1235.jpg
^^my dad fixed my mid pipe, it was cracked all the way around.

[Gibson]

well i got it running today, i've already ran one tank of gas through it:p We had to let it set for about five minutes at a really high idle to break the cam in, and then i rode it around the rest of the day. I never got it past half throttle but i can already tell a HUGE difference in power. Have a couple of questions. Is it normal to run a little hot during break in? and does the Hotcam produce more topend chatter than a stock cam? If so, how much more noise does it make?

[rob_990]

yea its normal for it to tick louder with a cam in it.Did you adjust the valves for the cam?

[Gibson]

yea, we adjusted them to spec.

[F-16Guy]

Did you re-jet before you fired it up?