FZR250 track bike

So, I signed up to a YZFR125 forum, but they're not so quick at weighing things. Unsurprisingly they mostly just want to know if the FZR250 motor can be put into the YZF - who can blame them.
Anyway, jury is still out until they get back to me on wheel weight.

I've yet to ask whether anyone has ever managed a twin disk set up on the YZF front wheel. It looks like there's no bosses cast, so no oppurtinity, by maybe an enterprising china man is knocking out twin disk variants, (probably out of cast iron!)

 

You are of course correct mboddy, I probably don't need more than a single large disk, I'm just a slave to fashion. Hang on a minute, current trend is for one. Okay, I'm a slave to 90's fashion!
I always worry about all the bending in a single fork leg though, but you are right, one is enough.
I intend to run on the road as well, so although sticky tyres are in, slicks are out.
I've been using the BT45's I brought it on, and I'm sufficiently slow that I've got no complaints. They are good enough to have everything grinding away so I can't lean any further anyway. I doubt there's enough power to highside unless you get a real rush of blood to the head.....

Anyway, I had a bit of blitz on it this weekend as I'm at the track again on the 19th of this month.
Somehow I convinced myself that painting the shock spring yellow would make me go faster, so I had spent most of the week building a shock compressor to get the spring off.

Anyway - with road in mind I made up a bracket to take the number-plate as I'd chopped it all off the subframe - see below. This bracket bolts on to the back of my shorty frame - also below. I can take it off when at the track. It's just a peice of bent 10mm tube with a couple of tabs welded on.

I also reassembled the subframe and all it's bits and bobs, also shown below. It all seems to fit. Also the new battery box. Just body work to go really.

 

Battery box
You’re always going to be fighting a loosing battle when making parts out of metal to to replace plastic items. The only way to make yourself feel better is to get more purposes into the same component an throw some others away.
Std plastic battery box 132g
New item, including rubber insert, retaining strap and fitting clip is 444g. I could drill some big holes in it, but I quite like the look of it, and no bodywork covers it, so I’ll just have to suck up the weight increase.
300 g typing it small makes it not look so bad!
On the up side the battery is some 50mm forward at 40mm lower, which is good, and space above it allows some other electrical and exup motor to move out of harms way as discussed.

[/URL

 

Well, whoever moved this thread out of yamaha 250 4's forum: why you swine, how long did it take me to find it? Thought I'd had too much thinners and dreamt it all!

Long story short, got it all back together for the 19th.
Who says it's not sunny in the UK.
A short bit of rear facing - look at how much the 250 get's nailed on the straights.
Turn the sound up as the exhaust note rocks, as does a bit of scraping.

A somewhat inevitable conclusion. Dejected walk of disgust at the very end.

 

I must admit I'd not given much thought to changing them to something else as I assumed nothing would fit, I'd more been trying to think up a way to jack up what I've got, but they really aren't suited to this, well not with the capabilites I've got in my shed.
You could of course machine some longer/higher versions of the existing mounting plates, but your's talking CNC milling really as they've got a counter bore with a flat in it to stop the pegs turning.
If there's something else that will fit then I'll try some.
That link Mclaren put up is for a company that's only 20 miles up the coast from me so maybe I could go and have a measure up, or a converstion with them about what will fit.

I'd tried winding up the pre-load on the rear shock to get some more clearance, but all this really did was make the back harder than the front - which whilst it didn't matter braking hard or accelerating hard, it didn't help mid corner. I rather put up with is being a bit soft then have it unbalanced. I really need to stiffen the front end, but that's for another day.

Are all FZR400's the same, or do I need to be look a specific model?

 

Yes, all faired pretty well thanks Moo. I had a look at some tank mount video of that day and it looks like I was doing somewhere between 75 and 80 Km/h at the apex here, so it wasn’t a too bigger off.

I managed to keep my head off the deck so avoided the marshal removing the sticker from my Arai, which was good as it cost more than the fizzer! My leathers are made by a one man band (well and his wife) in the UK called Crowtree Leathers and I think are made from rhino hide - indestructible. A club racers favorite they will take a whole season of crashing twice a weekend before repair is required. The downside is they weight the same as a lead elephant.

Below is a pic. of the fizzer post crash. You can see a bit of screen is missing, . The stator cover was cracked before, so all it got was a bit of scuffing. The tank was also already dented. I haven’t looked inside the stator, but I got back out and did another 4 sessions after this, so I assume it’s fine. Best check before next day out.

Biggest pity was the exhaust damage as I love the look of it and doubt I’ll ever find another in the UK, but it’s still serviceable.

Fairing got a bit scuffed – but it was cracked anyway. Excuse the “pursuit” decal which is actually made up from electrical insulation tape. My little lad and I were trying to decide if a “mad max” pursuit car yellow and blue scheme would look any good, and he begged me not to take it off - oh the shame.
All in all - no problem.


ooh, this picture looks weird - The fish eye lens has made the tail piece look huge. It's not, the rear of the tyre, the end of the can and the tail piece are all on a vertical line. Need a better camera.

 

@Moo - just read your thread - and seen your stator damage - ouch! I don't think I had anything like this, but I'm going to be checking round the back of the backing housing for cracks that's for sure

 

@Moo - caution regarding the stator windings on 2KR vs 3LN, they may be interchangeable but they are definately not the same part. The 2KR has 12 windings and the 3LN, well more, 18 or something. I thought there was a thread on here or maybe FZR250.com about it, I can't find it now. Them being different doesn't mean it won't work of course.
The tail peice is RS250 (honda not aprillia) early to late 90's I think from a UK supplier, but it took lots of subframe mods - pretty much a new one - to get it to fit.
The exhausts were both of ebay for little money. One benefit of there being so few fizzers in the UK means that when they did come in they were good examples, and that if the two other guys who've got one aren't looking for parts at the same time as you then they're cheap. I think that exhaust cost me £35, thats 63 aussie dollars! The DIC can was £0.99 plus £5 shipping. I was surprised it turned up.
Whilst 400's were very popular during the grey import boom of the 90's in the UK, 250's were almost totally ignored. They got hit badly by the insurance banding at the time which put them in with 400's. Although they are advertised from time to time i've not even seen another 250 4 cylinder 4 stroke from any manufacturer on the road or at the track for 10 years- but then I don't get out much!

 

@fnq-fzr, right then Jason, fzr 400 items it is then. There were lots of them, do you know which model yours were off?
Suspension has to be next on the list - probably r6 rear shock as there are loads of them about over here, and I was thinking of later TZR125 forks, or maybe TZR250 as they're not so rare here, but both are USD's so would new new yokes and clip-ons aswell.
The million dollar question is do you know the part number of your racetech springs, as of course the fizzer is not listed in ther online catalogue. This seems a much easier route to me, especially if we know it works.

Also, there seems to be some confusion with the tubular pre-load spacer in the fork on top of the spring, I haven't worked out which 3ln1,3,5 etc had what. The parts manual shows them all the same but this is clearly not the case. Anyone know anything about this?