Second Gen Trackbike - From beach debris to semi-maybe-competitive

[ck.mecha]

Just posted my intro, now time to jump right into my build thread.

I had been looking around for a small displacement track bike candidate for a few months. I found some first gen contenders in the budget real close, but nothing that grabbed my attention.

I finally picked this little POS up off eBay for a winning bid of $900, drove 500 miles RT to get it, and.....it doesnt crank. Negotiated $100 off and signed the title hoping for the best, what did I get myself into.

It was described as running but rough. I knew from the pics I had my work cut out for me so after I got it home I wanted to make sure it was worth throwing any effort at. I tested the compression, and while on the low end of the service manual both cylinders are OK for now. I couldn't get it running so I only had cold measurements, im sure they will go up slightly at temp.

Next step: pull the tank and carbs. As you can see, this thing was covered in sand. Sand everywhere! Also plenty of hacking as can be seen by the bolt in the breather tube. Turns out one of the cylinders had a CR8E plug while the other had a CR8HS... idiots. Also the vacuum and drain lines from the airbox were all unattached.

Expenditure:
Bike: $800 + $45 gas
Haynes Manual: $26
Spark Plugs: $10
Total: $881

[ck.mecha]

So I took a few hours and pulled the carbs then spent a few bucks on carb cleaner and went to town. Pulled all the way down and spit the carbs, cleaned them out thoroughly and reassembled to the base specs in the manual.

Turns out they had the idle air screws on both carbs out about 4 turns more than the manual calls for. I dont think there is any reason for that as all components are stock on this bike. Also, the needles were switched right/left...

Anyway, got everything back together, popped the cleaned airbox back on, drained the tank and replaced all vacuum lines and miracle of miracles she fires right up

So now that she runs its time to make plans:
This will be a supersport build, mostly for trackday duty. I want to keep it as close to WERA legal as I can to possibly run a few events. Based off what I spent initially the budget here is $3k, and I think I can build a pretty decent fun bike for that.

Expenditure:
Bike: $800 + $45 gas
Haynes Manual: $26
Spark Plugs: $10
Misc: ~5% added at end of build
Total: $881

[ck.mecha]

I almost immediately started purchasing the needed parts for this. Here are some of the parts I purchased that either are or will soon be installed. All of these prices include shipping where applicable.

Expenditure:
Bike: $800 + $45 gas
Haynes Manual: $26
Spark Plugs: $10
Swingarm Spools: $10
Rearsets: $150
Keyless gas cap: $27
Short levers: $25
Antigravity SC1 Battery: $101
Tyga Perf. Full Exhaust: $403
Gaskets, cables, screen (Tyga): $77
Hotbodies full set: $440

Subtotal: $2,113

Headlight: -$60

Total: $2,053

[netdobeiras]

nice job. happy modding.

[Sirref]

Looks good so far

I'd finish out the build with springs, emulators, and a new rear shock (the gsx-r swap is popular and inexpensive) along with a good airfilter.

I'd say that'll put you at your budget with a bike that's good to go

on the project so far

[csmith12]

Nice!

[ck.mecha]

So after it was running I stripped all the plastics, misc brackets, wiring, carbs, etc. Then tapped up all the exposed engine ports, and rolled it outside for a nice bath. Grunge everywhere, but now its easier to work on.

Since I was cleaning everything I went ahead and chopped the sidestand bracket off to avoid grinding dust once I get to the clean build stage.

Once back in the shop I pulled the exhaust and installed the Tyga system. My overall impression of this kit is for the price it is extraordinary value. The welds are nice, there are no kinks or reductions in the bends, and the general fit and finish are around what ive experienced with Yoshimura, Leo Vince, etc on larger bike. The only problem I had was when tightening on the manifold brackets they would deflect just slightly enough to make it difficult to slide the header pipes in. These bolts cannot be torqued all the way down before the header pipes are installed; not a big deal for me. Still have to fab up a silencer bracket.. Stock header and silencer weighed in at almost 15lbs on my scale, while the shipping weight of every single thing I ordered from Tyga including the packaging was 9.9lbs. I suspect the system itself is pretty close to half the weight of stock.

I did notice when taking the old system off that the right head flange was bent and there was evidence of an exhaust leak. This thing must have been a pig.

After that I got to work on the only thing on this build that may be controversial. While WERA supersport rules do not allow modification of the wiring harness, I feel any competitor who takes exception to making the bike easier to work on is a d**k. I plan to cut out all the signal stuff, safety start, etc. I will leave the connectors for the headlight and taillight as those are specifically mentioned. Once i split the loom i wont be hacking on any of the other wires for the starting or charging circuit. If anyone makes a fuss about this new looms are <$30 on eBay.

[Bigballsofpaint]

Originally Posted by Sirref

Looks good so far

I'd finish out the build with springs, emulators, and a new rear shock (the gsx-r swap is popular and inexpensive) along with a good airfilter.

I'd say that'll put you at your budget with a bike that's good to go

on the project so far

What he said plus some good tires and id consider the build done, nice job on the rescue.

[ck.mecha]

Originally Posted by Sirref

Looks good so far

I'd finish out the build with springs, emulators, and a new rear shock (the gsx-r swap is popular and inexpensive) along with a good airfilter.

I'd say that'll put you at your budget with a bike that's good to go

on the project so far

Thanks, thats pretty much the plan right now. I have ordered a shock that is not the ubiquitous GSXR swap. Ill stay silent now till I know it will work.

[AwDang]

Originally Posted by ck.mecha

After that I got to work on the only thing on this build that may be controversial. While WERA supersport rules do not allow modification of the wiring harness, I feel any competitor who takes exception to making the bike easier to work on is a d**k. I plan to cut out all the signal stuff, safety start, etc. I will leave the connectors for the headlight and taillight as those are specifically mentioned. Once i split the loom i wont be hacking on any of the other wires for the starting or charging circuit. If anyone makes a fuss about this new looms are <$30 on eBay.

just tape them back into the harness wrap.
The rues do specifically say. "If it doesn't say you can, you can't"

[ck.mecha]

Originally Posted by AwDang

just tape them back into the harness wrap.
The rues do specifically say. "If it doesn't say you can, you can't"

I completely understand this, and im fully prepared for this to be a wasted venture.

That being said, i feel the spirit of superstock rules is to limit performance upgrades and retain a semi-stock looking bike. Cutting out the sidestand wiring for example, is not going to make me any faster nor make the bike look any less stock. Like I said, this may be the most controversial part of this build.

Im not in this for purse money, so if a competitor takes exception im prepared for the consequences.

[sowega]

Originally Posted by ck.mecha

So after it was running I stripped all the plastics, misc brackets, wiring, carbs, etc. Then tapped up all the exposed engine ports, and rolled it outside for a nice bath. Grunge everywhere, but now its easier to work on.

Since I was cleaning everything I went ahead and chopped the sidestand bracket off to avoid grinding dust once I get to the clean build stage.

Once back in the shop I pulled the exhaust and installed the Tyga system. My overall impression of this kit is for the price it is extraordinary value. The welds are nice, there are no kinks or reductions in the bends, and the general fit and finish are around what ive experienced with Yoshimura, Leo Vince, etc on larger bike. The only problem I had was when tightening on the manifold brackets they would deflect just slightly enough to make it difficult to slide the header pipes in. These bolts cannot be torqued all the way down before the header pipes are installed; not a big deal for me. Still have to fab up a silencer bracket.. Stock header and silencer weighed in at almost 15lbs on my scale, while the shipping weight of every single thing I ordered from Tyga including the packaging was 9.9lbs. I suspect the system itself is pretty close to half the weight of stock.

I did notice when taking the old system off that the right head flange was bent and there was evidence of an exhaust leak. This thing must have been a pig.

After that I got to work on the only thing on this build that may be controversial. While WERA supersport rules do not allow modification of the wiring harness, I feel any competitor who takes exception to making the bike easier to work on is a d**k. I plan to cut out all the signal stuff, safety start, etc. I will leave the connectors for the headlight and taillight as those are specifically mentioned. Once i split the loom i wont be hacking on any of the other wires for the starting or charging circuit. If anyone makes a fuss about this new looms are <$30 on eBay.

Nobody is going to protest you for cutting off the light wires, etc.

With that said, we just taped them up out of the way on both of my bikes.

[AwDang]

Originally Posted by sowega

Nobody is going to protest you for cutting off the light wires, etc.

depends on how well his beer cooler is stocked

[tgold]

Originally Posted by ck.mecha

After that I got to work on the only thing on this build that may be controversial. While WERA supersport rules do not allow modification of the wiring harness, I feel any competitor who takes exception to making the bike easier to work on is a d**k. I plan to cut out all the signal stuff, safety start, etc. I will leave the connectors for the headlight and taillight as those are specifically mentioned. Once i split the loom i wont be hacking on any of the other wires for the starting or charging circuit. If anyone makes a fuss about this new looms are <$30 on eBay.

There are a lot of things that would make the bike "easier to work on" that aren't allowed in WERA rules. Cutting out all the signal stuff, safety relays and such reduces weight. You know that. It won't make any major difference, but it is still illegal. Do it if you want, but WERA is very strict with this class and you don't have any room to call somebody names if they protest you and you get disqualified.

If you really want to get a legal advantage and be completely within the WERA rules, try different bodywork that is more aerodynamic. There is huge potential there to get an advantage without doing anything that is illegal.

I'll add a couple more thoughts:


Don't throw out an insult by calling anyone who doesn't agree with your view a d**k. It might just have a effect that you didn't want.

If what you're doing is ok, at what point does it become not ok? How do you you figure that out without causing controversy?

Lastly, If you're going to break the rules, be a little smarter and at least keep quiet about it.

[ck.mecha]

Nothing much to report today. Replaced the missing hose clamps that hold the airbox to the carb with some new SS ones. SAE size 32 work well for these if you are trying to source any.

Also replaced the rusted, rounded, and partially missing pan head screws on the carb bowls and diapraghm caps with nice SS socket head cap screws. These are M4-0.7x18mm for the caps and M4-0.7x14mm for the bowls respectively.

I should add these to my budget, but I dont pay for hardware like this so ill cheat here a little.

Also chased all the threaded bolt flanges on the chassis with a tap to clean them up.

[ck.mecha]

Its been a LONG time since I updated this thread so ill add a couple of pics of the completed bike to take a look at.

First the completed bike, without even a scuff on the tires..

[ck.mecha]

Then the next thing that may be of interest to the board is the aluminum front subframe. This unit is from Motoholders out of CZ. It was 170 euros, about $190 at the time, including shipping.

Its a very nice unit, really light and the welds are perfect. It did need a little tweaking but no problem. I mounted a new Mychron 5 which I love. The function that tells you if youre faster or slower than the last lap is really useful for refining lines.

[ck.mecha]

I had 10 each right/left of these aluminum front spacers made. The speedo side has two recesses that I epoxied neodymium magnets into. It does help removing and installing the wheel. I have 4 sets left if anyone is interested, $40 shipped.

[ck.mecha]

A couple of other notes about the build

-Hotbodies plastics were cheap from Motorcycle Superstore at $440 shipped. I however was not impressed with the fit. Had to do all kinds of tweaks to get it to fit like id want

-Sportisi seems to no longer be in business, but I was able to order a RPM triple clicker from indonesia. It seems like a nice bit of kit, time will tell

-I did not go with the GVE in the forks, instead opting for the Mupo valve kit. It does have separate adjustable shim stacks for the compression and rebound, but I sheared the aluminum holder trying to get it apart to change the shims. I had my machinist make new holders and used their shims. Works the ****.

-40 pilot is way too lean guys! I installed a Z-tronics logger and i cannot believe everyone is getting away with a 40. I only have wideband and RPM being logged at the moment, but I have plans to add TPS and MAP.

-I know a lot of you guys get good performance out of the Area P, but personally I think it adds a bit of ugly to an already ugly bike. The Tyga I chose is a good value and already has an O2 bung which made life easier

-Youll notice a 415 chain kit, I recommend Speedmotoco highly for that. Shipped quick and Brian was helpful

-I tried to order a set of Dunlop Alpha 13 from Race Tire Service, who is the only autorized Dunlop race tire distributor in my area. I had a completely horible experience. I cannot recommend them, in fact I suggest you avoid them. I eventually had to file a claim with my CC and go with a set of Pirelli Diablo Rosso II

[ck.mecha]

Maybe a couple of other notes from my build:

-Do not use Race Tire Service! I tried ordering a set of Dunlop Alpha 13 and had a horrible experience. Ended up having to file a claim with my CC and order a set of Pirelli Diablo Rosso II elsewhere

-I did not end up going with GVE, instead opting for the Mupo valve kit. It has separate adjustable shim stacks for the compression and rebound. Unfortunately the first time I tried to pull it apart to adjust the stack I sheared both shim holders. I was able to get my machinist to recreate them out of Stainless instead of what looked like a zinc die casting.

-Sportisi moto seems to be dead. I ordered the RPM triple clicker from Indonesia direct and had a decent experience. Its definitely the best bang for the buck shock on the market for the 250R. I did have to file a little away on the dogbones to get it to travel smoothly, so just something to consider.

-A 40 pilot is way to lean guys! I cannot believe people are able to run a 40 with pods. I installed a Z-tronics logger and have been logging the wideband and RPM, slowly adjusting my jets under actual riding. In the future I plan to add a TPS and Map sensor to help a little more. Im at a 40 pilot, 108 main, with 3 shims under the needle now. I need to bump up the pilot and remove a shim next time I take it apart and the O2 curve will be just about perfect

-I know many here get good performance from the Area P kit, but IMO it adds just a bit more ugly to an already sorry looking bike. The Tyga I chose looks great, fit and finish is good, and it comes with an O2 port ready to go.

-Youll notice a 415 chain kit, I highly recommend Speedmotoco for this. Brian was really helpful

[nickjpass]

Never knew that a modded wiring harness is illegal. I guess I will never be using my zx in any WERA events haha.

[ck.mecha]

Oh, and both fork tubes and the upper clamp were bent. I replaced the upper clamp for about $15, but could not find a reasonable option for the tubes.

We put them in the lathe and slowly bent them back into position. We were able to get the runout to under 0.02" but did put a couple of marks on them. Does anyone know good options for tubes? Im afraid if i buy a used eBay set ill likely end up with worse than I have.

[ck.mecha]

Originally Posted by nickjpass

Never knew that a modded wiring harness is illegal. I guess I will never be using my zx in any WERA events haha.

And FYI, I ended up NOT modding the harness. I did install a Woodcraft keyswitch eliminator sub-harness and rewrapped some of the harness to make it cleaner, but no wire cuts.

[JohnnyBravo]

Sweet build!!!

[nickjpass]

Originally Posted by ck.mecha

And FYI, I ended up NOT modding the harness. I did install a Woodcraft keyswitch eliminator sub-harness and rewrapped some of the harness to make it cleaner, but no wire cuts.

My wiring harness has no plugs for headlights, signals, etc. I have a DIY keyless ignition, and there are a few other little parts that have been cut into.

[RacinNinja]

Here's a dyno sheet from my 2011 with the same exhaust, stock airbox, K&N filter with snorkel delete. They sound good and make good power too!

[Bigballsofpaint]

Tyga and LeoVince make very good exhaust options for the 250, many just go with Area P due to their customer support on this forum, and they often do a group buy once a year here if there is enough interest. The performance across the 3 is almost identical so I don't really say one is better than the other.

Nice build BTW, I may have to pull my 250 out for a track day later this year I was hoping to put it back to the street but I don't know if ill have the motor swapped in my Duc in time.

[sharky nrk]

Love those spacers and fairing stay

[nickjpass]

Originally Posted by sharky nrk

Love those spacers and fairing stay

BUY A PAIR THEN

[ck.mecha]

Originally Posted by RacinNinja

Here's a dyno sheet from my 2011 with the same exhaust, stock airbox, K&N filter with snorkel delete. They sound good and make good power too!

Better than I would hope for! Can I ask about your jetting?

[ck.mecha]

Originally Posted by sharky nrk

Love those spacers and fairing stay

Anybody can make an offer on a spacer set, im not going to get rich on these things. Send me a PM. Im a mechanical engineer by trade and have some ideas for the rear too.

I highly recommend the fairing stay. I will confirm it works with the stock gauge surround and cluster too. I bought mine direct from Motoholders but Yoyodyne is their US distributor.

Works out about the same price as the one you see on eBay made from a couple pieces of flat stock and tube bolted together as well. lol

[RacinNinja]

Originally Posted by ck.mecha

Better than I would hope for! Can I ask about your jetting?

You can ask but I can't answer!

Here's why: A local shop tuned it for the previous owner. I bought it, put it on the dyno and it was perfect so I haven't touched anything and have no idea what jets are in it.

The PO wasn't exactly mechanically inclined and didn't know either. I figured if it wasn't broke, don't touch it!

[sharky nrk]

Originally Posted by nickjpass

BUY A PAIR THEN

LOL - you under estimate my cheapness (or poorness pick one lol)

[sharky nrk]

Originally Posted by ck.mecha

Anybody can make an offer on a spacer set, im not going to get rich on these things. Send me a PM. Im a mechanical engineer by trade and have some ideas for the rear too.

I highly recommend the fairing stay. I will confirm it works with the stock gauge surround and cluster too. I bought mine direct from Motoholders but Yoyodyne is their US distributor.

Works out about the same price as the one you see on eBay made from a couple pieces of flat stock and tube bolted together as well. lol

from another ME (well more by education these days than trade as my job is more project manager now than anything). Thanks for the heads up on where to get the stay. And since my current employer doesn't have any decent machine shop access, maybe I will pick up a set from you in the future since I don't have machine access to make my own .