WR400 - Supermoto Conversion + Engine rebuild

[rossonza]

Need to order sprockets/Chain at some point, Can anyone recommend the best gearing? i may pop onto the motorway when the bikes used, but for 1 junction max so top speed isnt too much of a worry.

Thanks

Ross.

[dt502001]

Hey Ross well that is a hard question to answer because if you run17 "SM wheels it changes the over all gearing.stock gearing is good for everything except long highway runs,but then again these bikes weren't made for pounding down miles on the slab so buy a different bike for that. The bike wheelies just fine with stock but if your thinking of doing stunt riding then get a way bigger rear sprocket

Use this site http://www.gearingcommander.com/ to get a idea as to what is what for different tire sizes and gearing you can play with the numbers and it will tell you how many links you will need for the chain as well.

[rossonza]

Ahhh perfect, thanks DT. The idea is to maybe try a bit of stunting on the SM wheels (wheelies will be happening for sure), but then have stock gearing for the offroad wheels. So ill just swap chain and wheels over when i need to.

thanks for the link!.

Wednesday's definately a go, so engine will be checked out, clean my carb, clean my air filter. Once shes running nice ill start looking into swapping the cams over (ive got YZF450 sat in a spares box) and other potential tuning routes.

got to save a few months for wheels, but what the point in having nice shiny road wheels if the bikes not running hey....

[rossonza]

Hi guys, Just an update to say..SHE LIVES!!

My friends Ian and Steve came over to help with the swap (i say help, they pretty much did it all)

Here she sits before we took the bottom end out:

Got the old bottom end fully removed:

New Plug:

Feeler guage out:

New engine in:

Subframe off to clean air filter box and air filter (helped get carb in too):

Here she sits, all plumbed in (however there were a few ports on the carb that didnt have any hoses any ideas?)

Heres a video of her running (took about 40 kicks), my legs actually aching now. found out it didnt need the choke on to start and kicked after the 2nd full kick.

After that shed go on 1st or 2nd kick:

VIDEO STILL UPLOADING - no air filter used during this run.

Turns out the water pump has a little hole in the bottom (as by design) but it was weaping a little coolant, so ill be replacing the water pump seals.

Also, Found the top of a valve which was obviously what caused the original motor death:

Will update with video's/more pictures shortly

Items remaining:

Clutch cable

Throttle cables

Pump seals

fit head bearings

fit fork seals

replace valves

push bike speedo

supermoto wheels

chain and sprockets

Oh and i need a decomp bracket if anyones got one? or can find one anywhere?

Ross.

[welshwan]

FUCK YEAH!!!

Problem shared, a problem halved and all that!

You're flying through this. RIGHT THEN- i am going to get cracking on my bloody DR tomorrow (for shames sake!)

[rossonza]

[rossonza]

Hahaa yeah the list keeps on growing..will be nice to have her fully sorted.

Anyways here the video

[dt502001]

When you do the fork seals depending on what you weigh dictates how much oil you put in ,I see the tag on the fork from the suspension shop who did the forks at one time anychance you weigh the same as what it's set up for?

Also there is quite the procedure to get the air out.Its not just dump x amount of oil in

Um your forgot to post the video as well

[rossonza]

Vids on the previous post. Looks like an image of the bike side on.

Thankz dt. Im 14 stone so will need to do some maths.ive got the full fork manual so I should be ok. Excited to be finally getting there

Ross

[dt502001]

Sounds healthy,but I would be concerned if the wp has been leaking,did it get over heated at some time.

Trust me when I say it's cheaper to pull it appart now and re do the head than chance it,friend of mine knew he was due for a top end service but thought it would be ok for 1 more weekend droped a valve and blew up the bike 3000.00 later he had it back together.

The cost of valves is cheap compared to blowing up the motor.And the only way to know how good the plating on the cylinder is to pull it appart and look ,I have seen bike's running and when the cylinder was pulled off you would wonder how.

I know you want to get out and ride it,,,but it could be a very short experience if you dont check it all out first. Hopefully everything is good and you only need to change out the valves,springs and keepers.I would not trust it untill I pulled it apart

[rossonza]

First thing before shes ridden is replace valves/springs. But can't find a uk supplier of titanium ones. So may have to go steel. Also im replacing the water pump seals whilst the engines drained and going to check clutch condition.

Its getting a full checkup before I mot her. Dont want to risk downtime over summer lol

[dt502001]

Found these guys but holy crap they are expencivehttp://www.oemmotorparts.com/cart_e.asp even with shipping I would think these guys would be cheaper http://www.webcamshafts.com/mobile/motorcycle/yamaha/yamaha_wr_400_f_(98-00)_dohc_5v.html at 1/2 the price or less per valve.

[rossonza]

I can pick up some wiseco valves for 50 quid. Is that kit worth the 200 dollars + tax + handling fees? Compared to swapping the cheaper valves more often?

Or shall I stick to oem and just replace often?

Sidenote: got the kick start technique about 50% just hard having no decomp bracket so im having to pull on the whole cable.

Thanks

Ross

[dt502001]

The choice is yours just check the valves often. Ti are lighter so less wear on the springs and the motor revs faster but realy unless your trying to squeeze out every last bit of hp not much difference and if your mainly street riding it you wont be running red line as often

No old peddle bikes kicking around you could get a brake lever and perch off of to hook up the decomp cable,had to do that 1 weekend took the brake and perch off the mountain bike the cable ends are about the same.

[dt502001]

Better yet is to put the HOT CAMS auot decompression cam in and gain th 9% increase in power,I put it in mine and never looked back just the fact you dont have to mess with the lever and nothing to break.

I think the 450 cam has it but uses a different chain

[blackhat250]

The video ,2 . Husqvarna 610 [ crazy stuff] , These guys aint gonna see pension age ...

[rossonza]

Ti valves would be ideal but I really cant justify the costs right now. But definitely will be upgraded in the future (along with the fc mx carb)

Hmmm I wasnt sure on the difference from the 450 cams and the hot cams. Im guessing you can run yz timimg with those as they dont have the decomp?

[dt502001]

No there is a pin that pops out and holds the right ex valve open and then pops back in once the bike is running.

Not 100% sure on this but I think to run the 450 cam you have to change the sprocket on the crank and run a 450 chain,I havent done it and done know anyone who has ,,the hot cams are the hot ticket no pissing around just buy and install.

[rossonza]

Suppose I could sell the 450 cams to part fund the hot cams.

Sort of hp are we talking with them installed? I still have no idea how hard shes going to pull standard let alone opened up a bit.

Should be exciting!

so it keeps the 1 valve open so its easier to kick but allows the bike to start?

Is this the setup you have?

[rossonza]

Forgot to ask. Can I just get the exhaust hot cam? Or do i need both?