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WR400 - Supermoto Conversion + Engine rebuild


rossonza
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Hi guys. Posted on the welcome page and just thought id start off my post today.

This morning me and some friends drove up to Nottingham to pick up my new bike. I got her off an ebay add last week.

Here she stands - 1999 (first regged 03) Yamaha WR400

th_20140330_115618_zpsebd942b5.jpg

As you can see theres quite a few missing parts (mainly the barrel and cylinder head), However she has YZF450 Cams and ive been told was over 52hp when she blew. (the barrel cracked so the guy started to break her)

Box of engine parts and boots and tyres the previous owner gave me with the bike

th_20140330_115626_zpsbb5c56e5.jpg

Came with a spare set of black plastics too.

So current plan is to

rebuild engine

check gearbox (for the 3/5th gear issues and selector fork)

braided brake lines

rebuild calipers

buy and fit supermoto wheels

buy and fit trailtech vapor dash (or similar)

either buy new plastics, or new stickers to freshen her up

Optional

Powdercoat frame

So, its now time to get saving for either full replacement engine, or get a piston/cylinder head and barrel (if anyone has any of those let me know).

Thanks

Ross.

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Good luck mate. Keep us posted with loads of pictures, we like pictures

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Thanks Jimmy, Just need to source engine components or an entire engine (finding it hard at the moment). So ill just be dismantling what ive got now and cleaning as much as i can. brake lines should be an easy first job. I'm actually away for while so nothings going to happen until at least Saturday sadly :-(

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looks promising! :jossun:

i will be following this thread, that's for sure.....see if you can get this done before i finally sort out my DRs tank lol.

Yeah plenty of easy jobs to do without the engine, brakes like you say, check wheel bearings, fork seals , that left hand guard looks snapped in the picture?

:hyper: whatever wheels you use the bike is a monster, but with those stubby SuMo wheels that thing will take corners like a boss....will leave any supersport on the real tight stuff.

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yeah, its getting a full going over, theyre not snapped they are just not done up tight and they dont loop back to the bars (they have a metal liner which holds their shape). I'll probably change them out anyways.

Looking at Excel/Talon (looking for gold rims reallt, if not black rims gold spokes).

I've not actually ridden a wr so it will be interesting to compare it to my old ccm r30.

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Should be able to accelerate about as quick as your old CCM, and i suspect even better round the corners. Might have to ride it a bit harder then the 600, but shouldn't be much difference between them when going flat out.

Heres one chasing down an XT660- might help you get some kind of idea.

https://www.youtube.com/watch?v=qPosze9lf0k

There is a video on youtube, every time i watch i can't help but seriously consider getting a set of supermoto wheels for the TE.

(skip to about 5:40)

https://www.youtube.com/watch?v=-1dInhZvy7o

Instead of getting the wheels made, have you looked to see if you can buy a set? (ebay) - might save a fair few quid?

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Yeah, im trawling gumtree/ebay. quite a few go cheap on gumtree opposed to ebay.

im hoping shes faster, shes going to have more HP than the ccm (ccm had 44) but weighed 150+kg's. Whereas the wr is 48~hp (ive got the 450 exhaust cam) and its 114kg~ from what ive read.

Any ideas on big front brake conversion? ,I've read about replacing the front master cylinder with a honda one, just no one mentions which.

Cheers

Ross.

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I did try to google the specs of the bikes but kept getting varying answers lol

In that case the WR will shit on the CCM!

Not sure what brakes are recommended for the conversion, i have been looking online- but a lot of post have just the before and after pictures with no word as to what they did, how they did it or even what they used to do it.

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Hi guys, Just a little update on what the plan is and what me and my friend steve have found today.

Put the bike on the stand and took all panels off etc.

th_Bike_Stripped_zps21a84ab3.jpg

Found the sprocket could do with erm.....replacing. (a few years ago haha)

th_Sprocket_What_teeth_zpsc4287a23.jpg

Found the chain sliders completely worn through the plastic/rubber and has just started ruining the slider metal and the chain

th_Chain_Slider_zpsc02ab6e5.jpg

So.... we started going through the rest of the bike and found the airbox has been drilled, Should there be a top on this too?

th_airbox_drilled_lid_zps6e7c0007.jpg

We then found this in the airbox:

th_Airbox_Metal_zps21e82eec.jpg

th_Inside_Airbox_zps724fbafb.jpg

Carb full of metal

th_Carb_Intake_metal_zps7a5b8143.jpg

Bottom end has bits of metal in

th_Bottom_end_metal_zps6eb3f6b7.jpg

So... Im on the look out for a complete engine now (anyone have one for sale? PM Me) From what weve found we think the top end dropped an intake valve/melted the piston then bits came back through the intake path.

We checked the gear cogs and they are spot on so worst case ive got a spare gearbox.

Overall the bikes in a bit of a mess and also needs headbearings and fork seals but.... I bought this as a project and it looks like its going to be a fun one.

I've ordered the fork seals and head bearings etc... so ill update once ive got those bits (or an engine haha)

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no messing B)

you're getting some good progress done.

I'm sure an engine will turn up, just keep an eye out. i do check ebay every now and again.

At this rate you'll be good to go for the summer and happy to see that there are lots of pictures too!!

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already spoken to him, its all odd parts from all models of bikes. the heads a wr450 head, Id rather buy a complete engine or just the top end complete. then if it came off a running bike i shouldnt have too many issues. Watching a top end off a yzf426 at the moment but ive read you need a different crank. So i've messaged him asking if hes got the 426 crank still.

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Ok a quick search and the 426 and 400 share the same stroke of 60.1 mm the only difference is the bore 92.0mm vs 95mm 426, So the 400 crank will work with a 426 barrel,,,the 450 is a stroker of 63.4mm. so the barrel will be taller to accomidate the stroke and yam could have moved the studs.

As for comming of a running bike and no problems well not true,,it's nic coated bore so a 400 barrel could be bored out and recoated to be a 426, the used barrel will have to be recoated,well I would recoat it so you know it's new and not going to flake off after a few miles.

Now this I dont know,if the head will bolt into place from a 450 then there is no reason to not use it,it will be flowed to provide more fuel for the 450 so essentaly a free porting job. So find out what the measurments of the studs are and if they match then go for it.

Valve and valve spring life is short on these motors so you will have to check them as well valves strech and springs warp,so what I am saying is as long as you can find some good castings to work with then buy them and recondition them.The mian reason why these motors blow up is because people dont change the valves and springs as per the maintence schedual.

Crank and tranny bearing should be changed as well,split your cases and check the tranny bearings bet you will find at leats 1 that has worn and notchy.In comparresion to a rd 350 the bearings are 1/2 as big.

Any used motor realy should be striped and checked with the age of the motor,running or not will need work.

A 2000.00 dollar rebuild is about normal for these motors and the newer the head the easier it is to get better ti aftermarket valves, I have spent just about as much maintaing my bike's eng in the 12yrs I have owned it as I paid for it

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Hi, thanks for the technical reply. What i read from thumpertalk about the 426 top end was the wrist pin on the crank's difference (hence i thought id need a 426 crank) and they mentioned the piston would travel too high into the valves if i used the wrong wrist pin. But i guess this is wrong?

Id be doing a full strip down of any engine bits i buy, id also look at replacing the valves and lapping them. The 450's id need the electrical side of things, somewhere for the battey for the estart and the carb (all of which are more expensive than the 400's).

So basically as long as i get the whole 426 top end i shouldnt have a problem? (just the cost of replacing worn parts and potentially re-plating the barrel)

Thanks again

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