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View Full Version : rebuilding a crf for the first time



dazza1968
26-09-2010, 08:48 AM
Now a week ago i picked up a crf450x and decided to give it a rebuild and sort out valeves and head at the same time , please bear in mind i have never rebuilt a motor and its been something i have wanted to do :confused:

I have a manuel to suit a 08 450r and will use this for the best part and a bit of knowlwedge from some guys on here and also the internet and also Chris at Prestige Honda which has been fantastic really .

I dont think i would be so confident with out all the various areas of support also Padman is giving me a hand ,broken collarbone and all .

Started on tues by reading the manual Twice(Rare for a male i think) the second time reading it was good , Spoke to Smitto ,Paul,and Matty and also Chris so from Here i have started pulling it apart , now have containers to keep all parts in their place not like smitto with a full pile of bolts to go back together:eek:

Covers off, Cams off,Heads off ,did not take any readings of valves Just figured was doing the head ? Maybe not so smart :mad:Now after much thought i checked out Various options for big bore kits etc but off internet and will play it safe and pay the extra and use prestige honda to sort head (now was going to do valves myself but they dont do them so all i need to do is bring in the head Valves and all and rest is done in a machine shop), now back the the piston and rings , you can get all sorts od goodies over seas for very good prices now for me being my first crack at a rebuild felt i needed somewhere close to home to go and give grief to if no joy is being had .

Now pricing is anywhere for piston ,rings etc from 160 odd up to 400 odd , honda standard kit was 220

Valves vary alot as well s/steel is 400 odd as well

Big Bore kit (ego feeder Really) was 450 odd inc block so thought that was ok

I think the standard set for 220 from pretige is fine and just normal valves and do valve checks every 25 hrs so shoulh not be an issue .

now looking at the valves they were filthy, but looked ok , Please take into a/c i have not pulled off valves ,just looked .

Realised i dont have alot of special tools req did get a torque wrench yesterday.
Smitto has offered me his valve tool,Didnt have a cam chain tensioner but being a crf there isnt much room down below in the crankcase (not like the yzf) so it can not move around much,

Sunday am is planned to pull off block and piston etc ready to order on tues and put head in

Keep you updated and the odd photo if you want

Regards Dazza

dazza1968
26-09-2010, 02:47 PM
:eek:interesting pulled off the block today and there was small score marks on it and there was signs of a small amount of piston slap , i do have photos so will load on later i just hope you can see it. but i am pretty sure sand got in thru an air filter not correctly fitted as the filter was filthy also was sand inside the filter score on the bore could be from sand that got thru , so i think maybe a change of plans ,will reseat valves, put in new piston and rings , clean carby, and new filter for sure.

You know the valves all looked fine but will know more when dismantled cleaned etc

will keep you posted

Regards Dazza

p.s Does anyone know the difference between the hf2 piston and i have a new one for a 08 crf450r which has hf6 written on it But they look identical ?

any tips !

regards Dazza

p.s smitto can i borrow that valve tool ? will p.m you

Marty MOOSE
26-09-2010, 05:01 PM
Don't use any grinding past on the valves to reseat them will you! Really all you can do is recut the seats.

MM

dazza1968
26-09-2010, 05:08 PM
take a look at the air filter :eek:and can you see the scores on the bore , only small and not very serious i think but please correct me if i am wrong

dazza1968
26-09-2010, 05:12 PM
a couple similar but have different sun shades LOL:lol:

dazza1968
26-09-2010, 05:16 PM
Thanks Marty i was going to do just that . would you just get the shop to go over it or get a cutter and do it yourself

dazza1968
28-09-2010, 05:57 PM
Getting new inlet valves , going for standard piston kit , carby apart to clean out, Air box just getting pulled out for full clean out , Ordered oversize Radiators (not from Honda LOL), overall its going to be pretty cost effective really ,

Regards Dazza

Marty MOOSE
28-09-2010, 06:18 PM
You can't lap Titanium valves at all :) The exhausts are steel on the CRFX from memory (I'm a yammy man) the inlets are titanium most enduro riders who ride heaps change them to steels :)

karri
01-10-2010, 07:33 AM
Fuck me daz did buy another bike? You get it back together?

dazza1968
01-10-2010, 08:54 PM
no mate just waiting on the head then in it goes ,the buggers couldnt get it done so wont be this week end to sort it :-( Useing the spares kit from 08 450 and in it goes , Hey Karri what better way to learn how to strip down and rebuild than doing one for real :-) i must say there are lots of bits and pieces i am glad its one cylinder

dazza1968
05-10-2010, 05:59 PM
Head has just been picked up ,:eek::eek::confused:Now all that is left is to put this baby back together :confused:MMMMM will chuck a few more picks up soon

Regards Dazza

karri
05-10-2010, 06:01 PM
Yeah best way to learn.

dazza1968
06-10-2010, 09:19 PM
Just got in and may i say she is looking good:lol:New piston and rings are in , Blocks on,heads on,cams on , covers on all torqued up and looking hot to trot :cool::cool::cool::cool: Have some photos and will put them on later

Regards Dazza

smitto
06-10-2010, 09:41 PM
photos photos photos!

loudvs
07-10-2010, 12:02 AM
its bloody simple when ou get into it!

dazza1968
07-10-2010, 04:39 AM
Its not running yet Padman:confused:

dazza1968
07-10-2010, 04:42 AM
as promised more photos

dazza1968
07-10-2010, 04:45 AM
a couple of last photos before the big one (when Its Running ) cross my fingers

PaulMac
07-10-2010, 07:17 AM
Jeez Daz, no wonder you're buggered when we go riding. Working all day and then fixing bikes all night and posting on the interweb at 4.45am.

Champion effort........for an old bast*rd :lol:

So, are we gonna see it on Sunday?

smitto
07-10-2010, 11:20 AM
radiators look the goods mate, and yeah, nice late night effort

dazza1968
07-10-2010, 03:35 PM
Well I can tell you today I feel fucked:mad:but hey we are close but can you believe it put the carby on then not sure on hoses and forgot there was one there to look at ? Fucken knobs hey ! We are so close to having it running I Can
taste it , I think I will do a video for the start up ? Whatever happens will post it up so maybe some low flying swearing , drinking and cursing the good lord !!!!!???? Well maybe not that far . What I cam say is I want this bastard to just run and then sort out the bits from there . Regards dazza n pad as well

dazza1968
07-10-2010, 08:14 PM
well happy birthday to me after the earlier disappointment:mad::mad:, got the son of a gun running!!!!! oi it sounded bloody superb!!!! padman and i were bloody stoked will post video up asap. Hard Cock is all I can SAY!!!!!:lol::lol::lol::eek::eek::eek::eek::cool:: cool::cool::cool::cool::cool::cool::cool::cool::co ol::cool::cool::cool::cool::cool::cool:B)B):confus ed::lol::lol::lol::lol:

PaulMac
07-10-2010, 08:16 PM
Well done. Can I have a ride of it.........

thestewy09
07-10-2010, 08:38 PM
always a nice feeling when they fire up after having them apart

dazza1968
07-10-2010, 09:53 PM
Pauli take a spin
, I
must say it sounds awesome so hope the rest matches

smitto
07-10-2010, 10:48 PM
dibs on a go also...........its my turn now... not its not..... yeah it is, stop hogging it..... u stop hogging it... im telling mum.

you can have a thrash on my 250 on sunday if u like too paul.

does this mean your coming sunday daz?

dazza1968
08-10-2010, 07:05 AM
Yes will be there with my kids and their bikes as well , will get there a bit later than u guys .............

regards Dazza:lol:

Ryley
08-10-2010, 08:00 AM
Congrats mate, I'm looking to do a similar rebuild soon! :)

dazza1968
08-10-2010, 06:56 PM
latest pictures of finished product and a video ? just not sure how to load a vid but will try ,any tips on how to load :eek:

PaulMac
08-10-2010, 07:36 PM
[QUOTE=smitto81;2056824]

you can have a thrash on my 250 on sunday if u like too paul.

ooooooo, OK. Bit like wife swapping but with much less chance of catching something nasty :lol:

reddog
08-10-2010, 08:08 PM
With the radiators all bent up like that might be worth buying some radiator guards as well if you haven't already.

I paid around $100 for the DRZ guards and they have stiffened up the radiator like you wouldn't believe. Taken a few hits so far and no damage. Last thing you want is a smashed radiator whilst out having fun.

dazza1968
08-10-2010, 08:43 PM
Thanks for your thoughts i was going to get something just not sure what as yet ?

We made up a couple of covers today so no rocks damage the radiators on Sunday ,,,,,,,,,,,,,,,,,,,I thought it was sweet until i could hear a small squeak on the front wheel , greased back one when we put on a new tyre . so only little things now like the throttle is really stiff so bit bothered if i come3 off it may stay turned on and rev the crap out of it .

so a few minor bits and i nearly stuffed it up by using synthetic oil , Now has mineral oil in it . apparently the synthetic does not let the new piston and rings seat itself in ?

Now all swapped over .

and the seat height is a bit too high on this bike as well MMMMMMMMMMMMM:confused::confused::confused::confus ed:

regards Dazza

smitto
08-10-2010, 11:28 PM
latest pictures of finished product and a video ? just not sure how to load a vid but will try ,any tips on how to load :eek:

open a you tube acc and upload your stuff there, then use the insert attachments button to insert a image/video. i could def be wrong, but i had a few before i tried it late at night and it seemed to work for me.

smitto
08-10-2010, 11:35 PM
ooooooo, OK. Bit like wife swapping but with much less chance of catching something nasty :lol:[/QUOTE]

lol, yeah, like the keys to a daewoo.

Uni
09-10-2010, 12:04 AM
nice effort, looks like you've cleaned the bike up well too.

I've just completed a piston change on my 06' (same but older). I'm guessing that the auto tension was worked out since it's now running? My tensioner actually blew it's self to bits (causing an impromptu change).

Marty, titanium is the order for a stock CRF, I changed mine to steel about a year in from new... Never had a problem since.

dazza1968
10-10-2010, 08:05 PM
Took her out to metro rd today and she was fantastic , I really liked the gearing and at times the lecky start was gold especially when your a bit buggered .

Just wrapped

Regards Dazza

reddog
13-10-2010, 08:31 PM
If the throttle is stiff use something like silkolene silkopen on the slide and down the cable. Will make it silky smooth unless there si something severely wrong like frayed cable.

PaulMac
16-10-2010, 10:28 AM
Thanks for your thoughts i was going to get something just not sure what as yet ?

We made up a couple of covers today so no rocks damage the radiators on Sunday ,,,,,,,,,,,,,,,,,,,I thought it was sweet until i could hear a small squeak on the front wheel , greased back one when we put on a new tyre . so only little things now like the throttle is really stiff so bit bothered if i come3 off it may stay turned on and rev the crap out of it .

so a few minor bits and i nearly stuffed it up by using synthetic oil , Now has mineral oil in it . apparently the synthetic does not let the new piston and rings seat itself in ?

Now all swapped over .

and the seat height is a bit too high on this bike as well MMMMMMMMMMMMM:confused::confused::confused::confus ed:

regards Dazza

Dazza, try Ballards Offroad Dirt Bike Parts & Accessories Penrith Australia (http://www.ballards.cc) for a CRF lowering link. They are a nice red anodized link that comes complete with bearings and lowers the seat height 30mm. $249.00 plus delivery. You can phone them on 02 47311210.