[Shadow91]

Okay, so about a week ago at the dunes and noticed i had oil leaking from the head gasket. Finally got around tonight to tear down the inspect the engine and measure the bore. PO told me it had a stage 2 hotcam and a 440 kit but as i just found out, he was lying out his rear end. After measuring the bore, its an 85mm piston and looks to be a stock (very worn) camshaft. All in all, exactly what i was hoping for. Was also extremely surprised with how well the bike ran and how much power it had. When i removed the crank plug to rotate the piston, with the spark plug still in, i was able to move the piston with nearly just the weight of the ratchet.. I assume there should be considerably more compression on these..

Anyways, I want to do at the very least a top end rebuild. Thinking about doing a 416 kit and stage 1 cam. But from the looks of my head i need a new one.. center bearing has some pretty good grooves in it and i dont think there is much that can be done to save it (correct me if im wrong)

I want the best balance of power and reliability. So just off my head what i need is:

Wiseco 11:1 piston
Hotcams stage 1 cam
GT Thunder head studs
Cometic gasket set




Anything else I should worry about right now? What about valves and springs?

Anyways, few pictures of the parts..

First off the cam

The head

and the piston/cylinder

 

[Shadow91]

Okay, so i currently have in my cart;

JE 87mm 10.8:1 Piston kit (Piston, rings, pin, clips)
Cometic 87mm top end gasket kit
Stage 2 Hotcam
Hot cam HD chain
New OE chain tensioner
GT Thunder HD studs
Cylinder head from a XR400R (Ive read its the same, also has same part # according to bike bandit)
Lexx slip on exhaust
Carb rebuild kit
K&N Airfilter with pre filter




Anything else i should order? Trying to order everything at one time.

 

[Shadow91]

Clean your head up with Emory cloth and polish. If you put the bearings on the cam and place it in the head you will see that the cam does not touch the head. Under heavy torque it may flex a little but if you clean that up you'll be ok. I've done it before with no issues.
Use a UNI filter too Much better for off road than a K&N
Also replace the timing chain with Part# 14401-MEB-671 this is a 02-08 CRF450R/X, Replace the guides too and tensioner.

After sending out my head to get repaired, decked, and valve job done, found out the intake valves were toast. Would i be best off to get the kibblewhite intake valves by themselves? Or should i get the exhaust valves and their springs, especially if im going with a stage 2 camshaft, or will my stock springs and exhaust valves (which are in good shape according to the machinist) be fine with the new cam and bump in compression?

Also from friends that have done piston jobs and from reading online, Im told to do the JE kit over the Wiesco kit? Any input on this?

And lastly, Should i just go with a manual chain tensioner? Keep reading horror stories of tensioner failure. Planned on buying a new OE one, but if manual is a better option ill go that route.


Thanks for all the input

 

[Shadow91]

Okay well i finally got around to ordering my parts last night and somehow slipped up when ordering my gasket kit... I ordered a C7826-EST kit which is supposed to be for a 89mm bore. I needed to order a C7924-EST which is for the 87mm im going with..

Can i just order the correct HG from cometic or are other gaskets different with the kit?

 

[Shadow91]

Well sent Cometic an email asking about the difference in the kits and was informed it is only the head gasket itself. If anyone is wondering, a 87mm (416) head gasket is part #H0401SP2027S

All in all its actually cheaper this way, the 89mm kit was only $50 and the head gasket is $28, where as the 87mm kits i was looking at were $90 and above, so actually worked out better for me! haha

Also, definitely going to have to rejet, any one have any recommendations for what jet sizes? Im completely tearing the carb down to reseal it, Will have an open air box with an uni filter, stock header and Lexx slip on.. And then the obvious 416 kit, 10.8:1 compression with a stage 2 hot cam..

 

[Shadow91]

Okay, so the time has finally came for me to finish the build i started nearly 2 years ago. Going to start the build on the this thread and try to keep it here.

Sending out my cylinder tonight to get bored and HD studs installed.

Going with the JE 10.8 piston and hot cams stage 2 cam. Already have the HD Chain and kibblewhite valves.

Right now i have the stock carb and exhaust. Trying to get this at least running but on a budget. Can I get away with the stock carb and header with a slip on right now or are those going to be a necessity?

And what is the proper way to rebuild this engine? Just follow the factory service manual for timing and then rejet as i go? Whats a good starting point with the jets?

Thanks!

 

[Shadow91]

Would I be better to just order a dynojet kit or single jets? Sorry carn tuning is all new to me.

And then about to make a parts order, going with the lexx slip on and factory header should be okay correct?

 

[Shadow91]

Okay so I dropped the cylinder off to get bored on Thursday and am told itll be about a week turn around. Should be the correct size and have head studs installed just after Christmas! :yeahbaby01:

So I have a Honda powersport dealer right down the road from my work, i would assume i can just go through them for new jets? You said you're running a 170/48 in your 416? So would that be a good starting point for mine at sea level (Seattle, WA) or would you recommend any thing else? Im sorry, tuning a carb is foreign to me.

When i ordered my top end cometic kit, i accidentally ordered one for an 89mm bore. I keep seeing ads like this one that show they work for 87, 88 and 89mm bore sizes. Would the HG for the 89mm bore size work with my 87mm bore or am i just better off dropping the $45 for a new (correct) gasket? Would rather do it right the first time, but dont want to needlessly spend money if the other gasket will work.

 

[Shadow91]

So got my freshly bored cylinder back this weekend! Looks like its about time to start putting her together. From kinda going over the web i realized i was throwing away money - or power - with leaving the factory exhaust, so i ordered a Yoshimura exhaust and figured i would start with a 42 pilot and 160 main. Curious however if i should move the needle or not, right now its clipped centered. Using only Keihin jets.. thanks guys!

 

[Shadow91]

Well scratch the Yoshi pipe, got a great deal on a Duncan racing fatboy4.. should have it monday!!

 

[Shadow91]

Well go to install the head studs and find out that they were not drilled to the correct depth! Measured every hole and they all came out to be 1.82 inches! Spec is 2-2.22 inches for the GT Thunder studs!!

After some VERY CAREFUL drilled and tapping i was able to correct the depth and am awaiting some peratex sleeve retainer from the parts store.

So now time to rip the clutch cover off and replace the chain. Other then the case gasket, any other gaskets i should get for that or look at while its apart?

 

[Shadow91]

Well got to cleaning and rejetting the carb, having access to a ultrasonic cleaner is nice haha

Got the freshly bored cylinder back and head studs installed to exact depth.

And then finally got her to the shop to start this whole process! Man is this thing dirty haha

Should have the rest of my parts next weekend, hopefully burning gas by next sunday!

 

[Shadow91]

Yikes! That front stud looks nasty in the pic!

The head slides right over and it appears to be square in person tho.

However, I put the front/rear studs in backwards so I gotta swap those around.

All the parts should be here this Friday, if I do this right it should be burning gas by the weekend!

Quick question, I see a ton of post about porting the head, and a bunch of people saying that I’m gonna lose a ton of power out of the cam and big bore due to a stock head. Is the gains really worth it? I’m no

 

[Shadow91]

Okay. I might grab the dermal and just smooth the cast marks. Don’t think I’ll port it really. I don’t have the skills nor the cash flow, haha

Let’s talk about cooling mods real quick.
Different cooler, Different tank, Air scopes, etc.

Just don’t wanna overheat this after I’m done.

Rev boxes worth it with the cam and big bore?

 

[Shadow91]

Thank you misterclean59. Ive been googling, searching and looking at FB groups and these are all over the place. And then i find post from 10-15 years ago and just want the most up to date answers as possible. Im currently bidding on an aluminum oil tank so hopefully ill get that and scoops to start with.

Guess ill see how she does with all the new parts before i start messing with a rev box and all that.

Anyways, bought some used nerf bars last night. and my uni filter, oil filter and spark plug came in today!

Friday needs to hurry up. Should have my parts from them and my exhaust friday afternoon. My end goal in to hear this sucker fire friday night haha

 

[Shadow91]

Got the cylinder and piston put back on! But go figure i left the bolts at home lol

Clutch case removed

Chain off

and my parts!

Can someone provide me the torque specs for the clutch basket, the big bolt on the crank and basket as well? my stupid manual i ordered online wont be here until mid next week and was the first thing i ordered!

 

[Shadow91]

Yeah mister that’s the plan, just run it for now and if I fee I want/need a box I’ll get one later.

Gonna focus on cooling mods and suspension next. I’m sure this will be plenty for awhile.

Plus that the wife just asked for a quad.. so savings time again! ?

 

[Shadow91]

Well got the top end mostly buttoned up. New HD chain and cam installed.

Anyone willing to save me tho? I went to adjust the valves and two out of 4 caps broke off.. so i need new caps for the valve adjusters.. the 24mm ones..

if someone has 2-4 they are willing to part with and can overnight them to me in a small envolope i would be forever grateful. Just PM me your paypal info.

just awaiting the pilot jet and exhaust otherwise, both if which should be here friday! Shes getting there!

 

[Shadow91]

Yeah mixed dunes and trails. Would rather it be over cooled then under haha

Xplicit youre my hero, PM sent.

 

[Shadow91]

Okay, got her all wrapped up today!! Fired right up and is mostly broken in haha

So far all i can say is WOW. What an beast. This thing has no issues pulling the front up lol

But, go figure, my starter soleniod decided to give up, so new started soleniod ordered.. right now ill stick to jumping contacts

Also went back to an OE chain tensioner. Idk, just dont trust myself to set it right and would rather just not worry about it.

Also ordered new front plastics so i can get rid of the dang race cut up front. Shes just about done!!! (for now)

Want to say THANK YOU to everyone that helped!!