Project Rani - Yamaha SR250 Build - aiming to stay under $2.5k

asfi99

New Member
so my goal is to build a simplistic looking SR250, inspired by SR250 Mexico / Rachel and aim to keep it under $2500. I choose SR250 cause its a fairly simple motorcycle and i dont know much about motorcycles at all. So i figured it would be a great learning experience. And every project bike needs a name right so this one is called 'Rani'

Since i dont know anything about motorcycles my aim was to buy a motorcycle that was well kept and that wouldnt give me any engine problems. I found one for just under $1k - only 2nd Owner, very few miles, very well kept IMO.

Right away i am running into challenges so i figured i would start asking questions and help. I also hope to provide as much information as possible for the next person like me or for anyone looking for any source of reference

So far this is what i have done :

I want to paint the tank but the cheapest quote i can get was $300 so painting the paint is depriortized for now or i might take that on myself.

I bought new tires going to try to fit 130/90/16 in Rear and 100/90/18 in front (default is 120/90/16 , 90/90/18) , new tubes, and rim strips ofcourse - Total $250

New Antigravity 4-cell battery - $105

I changed the handle bar to an existing one that i had lying around - no cost

K&N RC-2340 Air filter - Not sure if this is going to fit, i have read you need a 55mm, (hasnt arrived yet) - $50 (amazon)

Turn Signals and Brake light - $50 (from ebay)

Round Odometer and tach to be purchased from DCC (around $100, havent purchased yet)

Next Challenges/Questions -

What to do with the seat ? - i absolutely hate the seat but cant find a good replacement either that will not require me to make some mods. I am going to call around and see if anyone can upholster the current seat and just make it flat-er (estimate around $250, i think)


Does anyone know what type of K&N crankshaft breather i need to buy ? i think its K&N 62-1030 but not sure

To keep the fenders as is, remove or shorten them? i want to shorten them but not sure how good a job i will be able to do with an angle grinder myself. Any tips ?

Anyways here are some pics - Day 1 when bike bought -
So far i have changed the handlebars and removed the chrome around the seat. Total Spent so far $1600 (approx)
 

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bgtuth

New Member
Looking forward to watching your project unfold! Bike looks in excellent condition, I'm currently starting on my own SR250 tracker build so as always it's interesting to see what people come up with.

In regards to cutting your front fender, just make sure its secure and you have a good pattern, don't try cut exactly where your line is and just carefully round it off with a good flat file! Speaking from experience maybe don't take too much fender off the engine side of the wheel, the previous owner of my bike did this and it barely helps in the wet ;) (Maybe something more like this http://3.bp.blogspot.com/-46T-G-gtI_I/UQaXoirkQNI/AAAAAAAAFTw/h2t5Lk9VsTU/s1600/sr250%2Bmexico.jpg)

Good luck!
 
SR250's are a neat little bike, cheap to run and modify. I did a quick look around the web before replying to your post and there are a lot of modified SR's out there to get ideas from.
Regarding a replacement seat, if you post or send me some frame photos in the seat area with measurements - lay a ruler or tape measure over the frame when you take the photos - I'll see what dirt track seats I make that would fit your ride.
Alternatively, go for more of a brat-style flat seat pan and if someone has given you a price of $250 for a one-off, padded and upholstered seat that's made to fit your bike, I'd say, "Go for it".
I'd ditch the side panels and make or buy flat or oval side covers (make it look like a number plate). I did rectangles on my tracker and makes a huge difference in the look. Don't know if I'd put "racing numbers" on them though, some of the DTT members get into a right lather if they see them on a street bike LOL.
The tank sits pretty high in the front - like a chopper or something. If it is within your budget, look for something else or lower the front mounts a bit if you can. If you pull the tank off and measure the length of the frame from the forks to the seat and the width of the top frame tube, I - and others - might be able to make a few alternate tank suggestions for you.
Your stock tank looks pretty good in the photos and you may be able to sell it and at least partially defray the cost of a new / other tank. A couple of SR's on the web use the smaller Honda CB tanks and something like that may appeal to you and not break the bank.
I like the black bars you installed and you've already said you were clipping the front fender (and I gather the back one too?).
Unless you've already bought the larger width tires, I'd suggest sticking with the 120 and 90 - the SR's have pretty narrow rims and you might find the wider tires "squirm" a bit when you're riding. You could look for a more aggressive tread in the narrow tires and still have a good tracker look. I'm using a pair of Duro DOT- approved tires on my tracker and they look like the same tread pattern as the Pirellis (MT53's) we used to dirt track on about a million years ago, but I don't know if they make them in your tire sizes.
With your budget, going to an 18" rear wheel is probably out of the budget and the narrower 120 X16 doesn't look too "chopperesque" to me anyway.
Have fun with your build and post a few photos as you make the changes.
Pat.
Vintage Motorcycle Fiberglass / Pacomotorstuff
pacomotorstuff@cogeco.ca
 

asfi99

New Member
Minor updates are coming along. I will try to get some work done over this long weekend.

Does anyone know if there is a way to install the Tachometer on the bike and if there is then instructions on how ? I bought the Tach and cant figure out how to install it now.

Here is a pic of the bike. Updates so far.

- Removed Front fender
- Removed Air Box and replaced with K&N 55mm Air filter K&N RC-2340 - I had to look forever to figure what size would fit and for future reference that should fit.
- Replaced battery with Antigravity 4 cell battery - u can see it dangling from under the seat. I have duct taped it for now until i put the seat in and find a more permanent place for all the electronics
- Replaced HandleBars
- Removed side mirrors (was not a huge fan - looking for a replacement)

Tasks for next week.
- Install new tires
- Install Speedo

Questions for group
-Any help with installing the tach would be so greatly appreciated.

Thanks
 

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zap2504

Member
OK - going from your initial statement ("Since i dont know anything about motorcycles my aim was to buy a motorcycle that was well kept and that wouldnt give me any engine problems.") I can tell you that you are headed in the wrong direction. Removing the air box will disturb the pre-engineered relationship between the carburetor and air box/inlet. Many others have experienced mild to severe lean running conditions doing this (which greatly shortens engine life); a few have re-jetted the carb to compensate but there have been no reports of a better running engine doing this. Also - just removing the front fender without any addition will cause both fork flex and a huge amount of dirt/water thrown up at both your engine and you. And you definitely need to be using mirrors as you are a newby rider. Get ones you like (and enable you to see the surrounding traffic behind you) that either screw into the original perches or into the ends of the handlebars (Napoleon bar-end mirrors are very well regarded).

I'm not sure what directions you need as you refer to both your speedometer (which contains the odometer) and a tachometer. You talked previously about getting a new speedometer from DCC. Is this the unit you are now looking to install? Does it have installation instructions? Many aftermarket speedometers require the mounting of a magnet to the wheel so the (new) speed sensor can sense the wheel's revolutions. The original speedometer had a cable that connected to a gear in the front wheel hub. This bike never did have a tachometer (in the USA) so if your new unit is mechanically-driven and your OEM was too you should be able to connect it up. If it is electrical, then you should be able to connect an input wire to your ignition (again, see instructions).
 

cosworth

New Member
I run mine with a velocity stack and some minor jetting. It runs strong for a tired old motor. Sure, it took about 6 jets to find the right mix but I'm happy now.

Once I port the head a bit, lap the valves and re-ring it along with a good head shave it will wake it right up. Might get 2-3 hp out of it. That's a lot on a bike that weighs 227 pounds.
 

zap2504

Member
cosworth said:
I run mine with a velocity stack and some minor jetting. It runs strong for a tired old motor. Sure, it took about 6 jets to find the right mix but I'm happy now.

Once I port the head a bit, lap the valves and re-ring it along with a good head shave it will wake it right up. Might get 2-3 hp out of it. That's a lot on a bike that weighs 227 pounds.
Unless you can prove it on a dyno (compared to stock) it is just conjecture. I have yet to see any engine modified by changing its air flow (filter, air box, etc.) and/or exhaust actually perform better than OEM. Maybe more noise, maybe different rpms for torque/hp but that does not make it "better performing". Shaving the head to give it a higher combustion ratio is a different thing, as is increasing displacement. I really doubt if porting the SR250 head will get you enough increase to justify the expense and re-ringing the piston and lapping the valve seats just gets it back to OEM (so maybe you're currently down 2-3 hp from stock?). My observation is that most people remove the OEM air box mainly for appearance and remove the exhaust for less weight (a very dubious reason given the total bike+rider weight) and sound - not performance increase - and both efforts usually have negative consequences (not the least is shorter engine life).
 

cosworth

New Member
You need to learn how to read.


I said rebuilding the motor and porting it will wake it up. I claimed nothing about the velocity stack doing anything.
 

asfi99

New Member
Thanks for your feedback. I should add that i have had bikes for a few years so experienced rider but havent done much with maintenance as most of them been Fuel injected and needs nothing more than an oil change and other basic maintenance. I should also add that i dont plan on using this as my daily commuter - i will maybe put 1k on it over the course of a full year.

Removing Airbox was purely for cosmetic reason and i fig i will need to do some carb adjustment. I def noticed some change but i will have to read up on how to play with Carb before i take that off.

As for the Fender again no plans for riding it in the rain unless it happens to pour on me but i see your point. I am considering shortening my fender but provided that i might have to paint it or get it chromed again that will be lower in the stack of priority to keep it within budget.

Lastly i really appreciate the critique but i would also appreciate some suggestions to help with the thought process.
 

zap2504

Member
OK you are not new to bikes, just older bikes with carbs. My previous comments were because you identified yourself as new to motorcycles. I don't care that much if an experienced person wants to blow up their bike with engine mods or suffer back pain with bad seat/suspension mods but I try to let new comers get the good info before they get in over their heads.

If you are still bound and determined to run with the aftermarket pod filter, you should look up what other SR250 owners have done (as far as carb changes with that SPECIFIC filter) as a starting point. Your results may vary due to different degrees of engine wear, location altitude, etc. Be prepared to spend considerable time either on a dyno, with an exhaust gas analyzer, or many, many "plug chops" at the 3 engine speeds where the carb's internal circuits come into play. You have to properly re-jet each of the carb's circuits for your new operating parameters. I see from your initial photo that your exhaust pipe is already turning yellow where it comes out of the head - that is a clue that you are already running lean (hot) and the chrome plating is discoloring (idle mixture too lean? carb passages/jets blocked? spark plug range too hot? IDK). Run too lean/hot for too long and you will damage the engine (and it doesn't take too long).

Running w/o front fender is just fine as long as you know ahead of time that the tire will be flinging dirt/water all up the engine and you (same thing will happen if you run w/o rear fender). You can fabricate a front fork brace to take the place of the front fender and reduce fork flex.

The tool I recommend quite often for proposed appearance changes is MS Paint. Take a good, large resolution side shot of your bike and import the photo into your computer. Open it up with Paint and "modify" the appearance/colors any way you want. Save each iteration so you can compare "concepts".

The least expensive/best running way to mod any bike is to leave the engine and related systems as stock as possible while making sure everything is completely clean and running in a good state of tune. Improve on the old suspension with better springs/shocks/fork oil/bearings. Improve on the old brakes with new pads/shoes/brake lines/fluid (the last 2 don't apply here, but...). Improve on the old tires (older than 6 years) with new. Then you can experiment on appearance changes like seat shape/height, colors of frame/body, handlebars, lights, etc. Mod the engine area or the suspension area too much and you enter into a long, expensive experimental process.

But it's your bike.
 

zap2504

Member
cosworth said:
You need to learn how to read.


I said rebuilding the motor and porting it will wake it up. I claimed nothing about the velocity stack doing anything.
I think someone else needs to learn how to read. I said that you cannot prove that running a velocity stack/carb mods increased your engine's power output (and I have not seen anyone else prove it either) whether it is "running strong" or not. I did talk to re-ringing (which is a part of engine rebuilding), porting (which is a change to the internal head passages to increase gas flow and is modification not rebuilding), and shaving the head (which reduces the amount of space in the combustion chamber and increases compression ratio and is modification not rebuilding). If re-ringing (or rebuilding) will "wake up" your engine then it is not currently making the same power that a stock engine in good tune (with an OEM air box) would. And I still stand by the statement that porting the head in a good-running SR250 engine will give little benefit compared to the overall cost. Neither will shaving the head. Now if you want to increase displacement by using an XT350 cylinder/piston...
/rant mode off/
 

asfi99

New Member
So i got the Seat from MotoLanna and it would be tricky to install it on the bike. Anybody install it yet ?

Basically the two metal pieces have no where to go under the fuel tank and i will have to cut them (in width) in half to get them to go under the tank.

I also have to drill two holes in the frame of the bike to make room for the two screws that goes in the back of the seat. I will also have to drill the holes at an angle cause the holes dont really sit right on top of the frame.

Any tips on how to best install this seat ?

On a separate note i really do love the seat its black seat with white stiching. Goes really well with the bike.
 

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cosworth

New Member
There is no way to install the seat without fabricating a mount front and back along with an undertray of some sorts. Look at my build thread and you'll see how I did it.
 

asfi99

New Member
cosworth said:
There is no way to install the seat without fabricating a mount front and back along with an undertray of some sorts. Look at my build thread and you'll see how I did it.
I did and i cant figure out how u did that :/
 

asfi99

New Member
Slow but steady progress as i can only work on the bike on the weekends. Still fidling with the seat but was able to get it to mount on the motorcycle, i will likely need to re-rivet the little bars on the seat to make them fit better under the seat. Installed a little angle at the back of the seat and put a screw through the end of the frame for the seat to sit nicely. But will need more work to fit securely.

Cleaned up the electronics under the seats, shortened the wires, relocated the solenoid to under the seat as well. The antigravity battery doesnt seem to be holding too well and needs to be recharged manually if the bike sits for a couple of days. Wondering if its not being charged, gonna test that out. Any body else have any experience with these AntiGravity battery.

Also moved the rear fender up and under the seat without cutting it which was great.

This concludes all the major updates so far

Blinker lights changed
Handlebar swapped
Front Fender removed
Rear fender shortened
MotoLanna Seat install
Airbox/Battery replaced
Wiring cleaned up
New Speedo
New Tires - Went one size up to 100/90/18 (front) and 130/90/16 (Rear)

Next step will be to clean up the bike and look at a Paint Job - Although i dont mind the current paint scheme all that much either.
 

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sincerelyadam

New Member
Hey Asfi

I like this build. I'm planning on doing some work on my SR250 over the winter. Of course I was considering the airbox removal, but I'm not sure since I'll probably be riding the bike a lot in the spring so I'm curious about the longevity of it. How did you find the airbox/filter swap to work out after riding it for a while?
 

asfi99

New Member
Summer Update: will make some more mods to the bike as time permits, Bike is an absolute blast to drive, i have left it gritty as i like the look much better and painting the tank was way too much $$$. Gets tons of compliments.

The battery not charging issue was easily resolved by replacing the voltage regulator rectifier.

AntiGravity battery is working out great but i replaced for the bigger 8-Cell battery, starts every time with choke.

Upgrading the lights to LED has caused them to stop blinking since they use way less power, i just need to buy a relay that regulates the blinking.

I loved the sound of the bike after replacing the airbox with pod filter. Its only a 250 but it grunts like a much bigger bike.

I looked into SR500 as a summer project but they are far and few and are going for almost new prices.
 
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