WR426F engine strip-down

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GLM
18/03/2007 at 23:00
Finally got round to stripping my engine after it trying to lunch itself over a weekend's laning in Norfolk last year.

What a ball-ache!

Everything had been overtightened, even ended up having to chisel off the primary drive nut.
Had to go and manufacture an uber-puller out of dirty great steel plate because my off-the-shelf on wasn't man enough for the generator rotor that'd been graunched up too hard on the end of the crank.

Found out that the big-end's starting on it's way out, which was the source of the tick that's had the bike laid up awaiting this rebuild along with the blown 5th gear that happened the same weekend.

Engine's got less than 1000 miles on it since its last rebuild, which included a new crank. Seems like it got an iffy big end bearing or the crank wan't pressed too well.

New Camchain, and countershaft sprocket seal's on the cards, and a water pump seal to be on the safe side as I'm in there.
Anyone got any experience of manual camchain tensioners on WR's, as the chain's knacked already. Heard of the auto-tensioners being too hard on camchains.

Any reccomendations for someone in the South East to do the big end if I give them the crank.

I'll be phoning Slipstream tuning and Bob Farham on wednesday for quotes otherwise.
Funners
18/03/2007 at 23:10
Thats a pisser that Matt....
Guess you wont be returning to the previous builder then ????


Not heard of any problems with the Tensioner myself...all mine have run the auto one with no problems at all...
I've replaced the chain on the 450 but only as a precaution....
Mister Farnahm is my Recommendation mate..
hope you get it sorted...
GLM
18/03/2007 at 23:20
Funners wrote
Thats a pisser that Matt....
Guess you wont be returning to the previous builder then ????


Not heard of any problems with the Tensioner myself...all mine have run the auto one with no problems at all...
I've replaced the chain on the 450 but only as a precaution....
Mister Farnahm is my Recommendation mate..
hope you get it sorted...


Makes me wonder if it even needed the new crank it had in it, or if they wrecked the previous one with a bad prior rebuild.

The camchain's goosed with very few miles on it, have either your 400 or 450 had much of an appetite for them?
moto
19/03/2007 at 11:38
Matt you could try Chris Applebee Engineering in Thundersley near Raylegh in Essex, for the bigend rebuild. He's been there for years & apparently Stan Stephens subs out work to him. I've used him for over 20 years & never a complaint. HTH.
Wheelies.They are big & they are clever!
japtimscarlet
19/03/2007 at 14:14
moto wrote
Matt you could try Chris Applebee Engineering in Thundersley near Raylegh in Essex, for the bigend rebuild. He's been there for years & apparently Stan Stephens subs out work to him. I've used him for over 20 years & never a complaint. HTH.



must be ME again ...Ive used applebee for two stroke crank rebuilds ...and Ive had complaints !!
SUFFOLK INBRED

past bikes

RD 200 YR5 350 XT500 (x2) YDS7 250 (x3) T20 SUPERSIX T250 (x2) DT175 (x2) DT400 RD400 RD350LC (x2) RD250LC HI500 KH500 RD375 SPECIAL Z1000 (x3) RG500 TZR250 (x2) XT250 CBR600 ZXR750 GSXR1100
1200BANDIT 900TRIDENT DRZ400SM YZ426SM WR426SM (x2) KTM SMC660 FE470SM CB450 FZR1000EXUP YZF750R XR250R XR600R (x2) KLR650 BULTACO 360 FANTIC 175 RD350YPVS etc etc etc
Hawkman
19/03/2007 at 17:55
David Lambeth Engineering nr Ashdown forest, if you want to try something different. Bore-tech any use to you.

Are you fit for climbing btw???
R.A.T.6

Don't have a supermoto, now I need viagra.

Crashometer
2006
2005: thats racing... and black ice...
Crashometer 2004:
Crashometer 2003:
pogie
19/03/2007 at 18:24
Hawkman wrote
David Lambeth Engineering nr Ashdown forest, if you want to try something different. Bore-tech any use to you.


Wasn't it Bore-tech who rebuilt the engine not long before Monkey-boy bought the WR.
Hawkman
19/03/2007 at 18:29
pogie wrote
Wasn't it Bore-tech who rebuilt the engine not long before Monkey-boy bought the WR.


Andy used them before he flogged it. Not sure if it was them or farnham, if you get my drift...
R.A.T.6

Don't have a supermoto, now I need viagra.

Crashometer
2006
2005: thats racing... and black ice...
Crashometer 2004:
Crashometer 2003:
Funners
19/03/2007 at 19:36
GLM wrote
Makes me wonder if it even needed the new crank it had in it, or if they wrecked the previous one with a bad prior rebuild.

The camchain's goosed with very few miles on it, have either your 400 or 450 had much of an appetite for them?


ahhh no comment...
cam chain wise..the 400 went with its OE one still in....
450 has had one change as a precaution..
GLM
19/03/2007 at 20:07
No comment preciseley.

After they changed a rear tyre for me, and only gave it back with one rimlock I was hardly impressed. Especially as I never got my other rimlock back, and the fact they never plugged the 2nd (now empty) rimlock hole.


and Hawkers, yeah, I'm up for climbing anytime, but my mobile's broken, I'll PM you my house number.
TeamScream
20/03/2007 at 20:21
ooops
www.teamscream.tv

2001 Yamaha WR444F

2003 Honda CRF450R
TeamScream
20/03/2007 at 20:23
TeamScream wrote
ooops


I have a Powerpoint presentation I made of the entire build process for the bottom end of a 426, super clear close up pictures of EVERYTHING you need to know about building a 426, it is so amazingly simple that once you look at it you will never pay someone to build your bottom end again, no special tools required other than a decent impact gun and a torque wrench for both in./lbs and ft/lbs, over there I think you guys go by the n/m thingy whatever but you get the idea im sure.
This is a 30 MB file that you can download from my site if you want it, but I am not going to post it here because I dont want to burn all of my bandwidth up with peeps downing it just to look at it.
If you need it and are going to use it then email me and I will make it available to you.
Scream.
teamscream ( remove this crap @) gmail.com

Here are some example pics from the presentation, these pics DO NOT have all of the instructions text that i included in the presentation which tells you exactly what to do at each step, but is an example of the type of pics included.

P.S. these pics are post case joining, the presentation shows all the parts laid out, tranny build up, joining the case halves and the whole lot.

















www.teamscream.tv

2001 Yamaha WR444F

2003 Honda CRF450R
JC-46
20/03/2007 at 21:35
Fair play dude.
Cant some bugger do a Berg one?

JASE DA RACING SNAKE
http://i167.photobucket.com/albums/u156/JCSUPERMOTO/09092007189.jpghttp://i167.photobucket.com/albums/u156/JCSUPERMOTO/Y.jpghttp://i9.photobucket.com/albums/a66/SUPER_JC/23.jpghttp://i9.photobucket.com/albums/a66/SUPER_JC/newsuperblogo1.jpg
aliceracing.co.uk/
APRILLA "JCB" 550
http://leejonesracing.blogspot.com/

LJ/WOODIE/MR A MITCHELL/STUPOT/PHIL G/DEANO/FELIX/CUZZA/FLAG WAVER

GLM
20/03/2007 at 22:34
Team Scream - Great job with the PDF manual, but I've no problems with building engines, this'll be my fourth.

If I could accurately press my own crank at home, I would. Unfortunately, as you know, it's a specialist job that's gotta be farmed out to a pro.
TeamScream
21/03/2007 at 00:21
GLM wrote
Team Scream - Great job with the PDF manual, but I've no problems with building engines, this'll be my fourth.

If I could accurately press my own crank at home, I would. Unfortunately, as you know, it's a specialist job that's gotta be farmed out to a pro.


Very cool GLM, I was just trying to be helpful where I can,
I hear ya on the crank job, however i do have a mate that actually cuts them apart with a cutoff wheel, then uses a set of V blocks and a dial indicator to get them lined up and dialed back in, never had one grenade yet.
I personally prefer to use someone like Falicon.
The real bummer is there is nobody that I know of still doing good 426F forged after market rods.
If you know of a company that produces one on your end I would love to hear about them, as my next deal is likely to be a stroked version.
I am bored with the overbore method, but I am still way in love with the 426 as a reliable platform from which to build from.
www.teamscream.tv

2001 Yamaha WR444F

2003 Honda CRF450R
japtimscarlet
21/03/2007 at 06:32
GLM wrote
Team Scream - Great job with the PDF manual, but I've no problems with building engines, this'll be my fourth.

If I could accurately press my own crank at home, I would. Unfortunately, as you know, it's a specialist job that's gotta be farmed out to a pro.



It is ???
shit, I'd better stop doing it for people.......
SUFFOLK INBRED

past bikes

RD 200 YR5 350 XT500 (x2) YDS7 250 (x3) T20 SUPERSIX T250 (x2) DT175 (x2) DT400 RD400 RD350LC (x2) RD250LC HI500 KH500 RD375 SPECIAL Z1000 (x3) RG500 TZR250 (x2) XT250 CBR600 ZXR750 GSXR1100
1200BANDIT 900TRIDENT DRZ400SM YZ426SM WR426SM (x2) KTM SMC660 FE470SM CB450 FZR1000EXUP YZF750R XR250R XR600R (x2) KLR650 BULTACO 360 FANTIC 175 RD350YPVS etc etc etc
GLM
21/03/2007 at 19:18
japtimscarlet wrote
It is ???
shit, I'd better stop doing it for people.......


Maybe I should have re-phrased it as 'it's not a do-at-home job for an amateur mechanic'

If you're happy pressing cranks in your garage, then cool. Me personally, I'll pay the 45quid it costs to have someone who builds reliable race engines day in, day out.
I've only gotta fuck it up, and I'd lose that much money in gaskets alone rebuilding it, let alone the rod kit.

Teamscream: I'm going for a stock rod again, stock 426 rods have done a good job before, and will continue to do so for what I want the bike for.
Must have just got a duff one, or had a poorly aligned crank.
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