PDA

View Full Version : Into the mix... RS125 4-stroke project



vfracer-r
10-22-2010, 02:11 PM
So I got a basket case RS50 sans engine a couple years ago, and recently began to get serious about getting it back on the track.

The good:
Frame, front end, brakes, swingarm, subframe, seat, 2 good tanks and covers, and a full set of Multi-tech bodywork.

The bad:
Ain't got no motor!

I have several parts for it, like the radiator and some wiring, but really all I have is a good rolling chassis.
I have an KX60 engine with electronics and is complete, but I wanted something with more grunt and more reliable for endurance racing....

So I found an old XL125 Honda and will be transplanting that in to the RS chassis over the next couple of weeks. The KX will be here in reserve just in case things go south or something.

I'll try to post regularly with progress and "before" and "in-progress" and "after" pics.

Dom.C
10-22-2010, 03:02 PM
Good luck buddy I'll keep an eye on this one for sure.

vfracer-r
11-01-2010, 03:35 PM
Damn forgot to take pictures!
Anyway, I'll try to get 'em tonight.

I have the engine mounted, carb on, exhaust on. Pretty painless with minimal welding. I'm trying to keep the integrity of the engine frame, I think too much welding will compromise that.

Pretty painless process so far, the exhaust is going to challenge me hower.

I'll try to remember pics tonight!

Crim
11-02-2010, 05:34 PM
exhaust on a 4stroke should be a breeze no? Just chop off the exhaust flange from the stock pipe, buy some mandrel bent exhaust pipe of appropriate size and cut/weld as needed? No pesky expansion pipe to deal with :)

vfracer-r
11-03-2010, 09:14 AM
exhaust on a 4stroke should be a breeze no? Just chop off the exhaust flange from the stock pipe, buy some mandrel bent exhaust pipe of appropriate size and cut/weld as needed? No pesky expansion pipe to deal with :)

This is true, routing through the frame whilst clearing everything is the only issue I've run in to.

I plan to make it by the local exhaust dude's shop. He builds fantastic 2-stroke systems, I imagine he'll be able to whip out a 4-stroke pipe in short order!

vfracer-r
11-22-2010, 04:38 PM
Well I'm almost done and I managed not to take any pictures!

I have the motor mounted and running, just need a front axle nut, front brake calipers, and a rear sprocket that matches the pitch of the front sprocket... the sprocket dilema might screw things up for me.

A quick mod list and I'll try to get some photos up tonight:

XL125 Honda motor
Custom bent exhaust with FMF muffler
GSXR radial front brake master cylinder
CR80 rear brake master cylinder
Multitech race bodywork set

I put on the two master cylinders listed because I had them laying around the shop and didn't have the originals. Otherwise I would have gone with the original peices.

Crim
11-22-2010, 05:42 PM
Well I'm almost done and I managed not to take any pictures!

I have the motor mounted and running, just need a front axle nut, front brake calipers, and a rear sprocket that matches the pitch of the front sprocket... the sprocket dilema might screw things up for me.

A quick mod list and I'll try to get some photos up tonight:

XL125 Honda motor
Custom bent exhaust with FMF muffler
GSXR radial front brake master cylinder
CR80 rear brake master cylinder
Multitech race bodywork set

I put on the two master cylinders listed because I had them laying around the shop and didn't have the originals. Otherwise I would have gone with the original peices.

Sounds like a fun project! In for pictures! Assuming you are stateside...for the rear sprocket call up the guys at rebelgears.com. Just tell em you have an Aprilia RS50 and are converting the chain to whatever you need. I think my 520 42tooth rear sprocket was like $50 shipped and they cut it the same day I called.

EDIT -- Oh and if you don't specify I think they'll send you the sprocket made in aluminum. I would have preferred a steel one myself.

garrett
11-22-2010, 05:49 PM
I can't wait to see it. Good choice on the motor.

jcb121
11-22-2010, 06:30 PM
Prepare for some two stoke elitism to come your way :)

Should be nice and reliable though :P

Get some pics up Seriously

vfracer-r
11-22-2010, 07:42 PM
Thanks all, here are the pictures. Oh, and Ted at AF1 hooked me up with the fattitude for sprockets, brake pads, and the axle nut! Thanks bro!

I am Stateside, Texas to be exact. And I would have preferred to go with a 2-stroke but the opportunity was too great to go with the 4-stroke. 'Round here in Tejas, the 4-stroke engines are just a bit more reliable.

http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02409.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02408.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02407.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02406.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02405.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02404.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02403.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02402.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02401.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02400.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02399.jpg
http://i141.photobucket.com/albums/r75/tommyp1/Aprilia%20project/DSC02410.jpg

vfracer-r
11-22-2010, 07:56 PM
Oh and the bodywork is getting painted, that was from the previous owner. Orrrrrrrrr, if someone has some primered bodywork that they'd like to trade for this set, I'd be game for that.

andy_edw
11-22-2010, 07:58 PM
whys the exhaust upside down

vfracer-r
11-22-2010, 08:04 PM
whys the exhaust upside down

Because I don't want to cut that pipe, it's from a full system KLX110 and I would like to keep it intact. In order to clear everything without having to cut or bend the muffler, it had to be upside down. Either that or I would have had to bring the head pipe down under the engine and try to route it out the side by the swingarm, and this way was a whole lot easier.

I'm all about easy. :ripass:

Crim
11-22-2010, 08:47 PM
hahaha looks good! Well except for that body work...man that's ugly!

andy_edw
11-22-2010, 09:03 PM
Because I don't want to cut that pipe, it's from a full system KLX110 and I would like to keep it intact. In order to clear everything without having to cut or bend the muffler, it had to be upside down. Either that or I would have had to bring the head pipe down under the engine and try to route it out the side by the swingarm, and this way was a whole lot easier.

I'm all about easy. :ripass:

you could of just said "It's a bodge" lol

vfracer-r
11-22-2010, 09:14 PM
hahaha looks good! Well except for that body work...man that's ugly!

Here's a pic of my old race bike. I'm not going to copy the design (that was conceived after huffing lots of paint fumes from another project...), but the pearl white was the tits!

http://i141.photobucket.com/albums/r75/tommyp1/Paint/JerrelsAprilia.jpg

http://i141.photobucket.com/albums/r75/tommyp1/Paint/JerrelsAprilia2.jpg

The previous owner of the black bodywork spent a lot of time at his air brush artist's shop... it's actually very good work, but quite hideous on a race bike! It would fit on a Harley very well...

I was thinking of doing the pearl white again with slight graphics, mainly keeping it simple.

vfracer-r
11-22-2010, 09:20 PM
you could of just said "It's a bodge" lol

I could, but I did it on purpose and I wanted it to be under-tail. Not to mention it was a conscious decision to keep the pipe intact. Besides, it's a race bike, form and function over looks for sure :peace:

andy_edw
11-22-2010, 10:45 PM
I could, but I did it on purpose and I wanted it to be under-tail. Not to mention it was a conscious decision to keep the pipe intact. Besides, it's a race bike, form and function over looks for sure :peace:


Very true, have you ridden it yet?

vfracer-r
11-22-2010, 11:12 PM
Very true, have you ridden it yet?

No, can't wait either. It won't be as much fun as the 2 stroke to be sure; too many limitations on what the 4-stroke can do in comparison to the valve-less plant. But as soon as the front sprockets come in, and I get the axle nut and brake pads, I'm going to hit a local track day here in December. Until that track day, I'm going to sneak out on the back roads for a little test-n-tune and figure out what gearing is going to work. I'm going to start with 13-45 and see where I'm at after a few back road sessions.

vfracer-r
11-25-2010, 04:23 PM
Test rode the bike today, gearing is way too tall with 14-43. I have a 45 and will pick up a 47 and 13 to see if I can sort it out.
Fresh tires from Bridgestone, tear the bodywork off and repaint, then a trackday on December 6.

vfracer-r
12-03-2010, 08:37 AM
Here are some pics from my impromptu late-night painting extravaganza! I was working on a friend's bike, getting it ready for the track, and doing an Attack Performance replica paint job. In between coats and flashes I got antsy and decided to scuff and shoot the little 'Priller. It's not perfect, and the color combo I used will benefit from some stickers to pull it together... not to mention I feel the need to mask and paint the black graphics on the tank cover the same color blue. I was able to locat a blue fuel cap so that helped, but the tank graphics look really out of place in black with the lower being that bright mettallic/ pearl blue. Oh well...

http://i54.tinypic.com/28t9ir9.jpg

http://i53.tinypic.com/x4psmf.jpg

http://i53.tinypic.com/4u81ev.jpg

http://i53.tinypic.com/2w57hc4.jpg

I think I'll get around to painting the wheels since they're pretty beat up, and the frame could use a good coat of powder too perhaps. Of course, if I race it in February before I do any more work on it, I'm sure it will continue to look as it is now! ;)

Rlhay2
12-03-2010, 09:49 AM
FB racing representin'!:peace:

vfracer-r
12-03-2010, 02:01 PM
FB racing representin'!:peace:

I dunno, I like 3X Racing from the good 'ol days! FB Racing is just too... descriptive... ;)