A forum for owners of Yamaha TTR250 trail and enduro bikes!

davecambo · Senior Member

do you need a battery?

TTRfan · Super Guru

I imagine you could lose all of the gubbins shown in the pic below plus starter and solenoid. You would need to blank the starter hole.

TTR starter clutch.jpg

davecambo · Senior Member

hmm. im not quite sure what the above is.....

I wonder if anyone would be so kind to assist me in understanding what i can remove to save weight that is easy. such as the battery, i know where it is, but what do i do with the pos and neg wires once the battery is removed. or can i trace them somewhere and remove them.

same as the electric start button on the handlebar. can i take that off and follow the wires and remove them? is it possible to remove the starter motor easily or does it require a lot of work.

i would love a list of things to remove. i have searched the net everywhere but cannot find anything but others asking same question.

TTRfan · Super Guru

The parts in the pic are the heavy starter gears and sprag clutch that live under the generator cover and connect the starer to the crank.

Must weigh quite a bit!

Are you going for a total strip down and taking off lights as well?

davecambo · Senior Member

no i need to leave lights and anything else required for road use or registration purposes. you cant ride through forests where i ride without a registered bike.

davecambo · Senior Member

not sure if im up to opening the engine case or anything, id be more interested in what i can remove that i can put back on later if i want.

brindabella · Senior Member

battery alternatives:

1. try removing it - see if the TTR still starts and runs, but you may still have problems with headlights at lower speeds, unstable voltage, more load on the voltage regulator;

2. replace it by making up and installing a suitably rated capacitor and zener diode as a "dummy battery" - may ameliorate some problems, but costs money and is one more thing to fail, and still the lights will be weak at idle speeds (and still no electric start);

3. replace it by a much lighter (but more expensive) lithium ion battery - save weight AND keep the electric starting convenience;

4. keep it standard - after all, its only a trail bike.

BM Steve · Guru

Hey Dave

Here's a link to a Lithium Ion Battery that Brindabella mentioned

If you want to save weight try that.

My preference would be to get rid of the headlight first and replace with something light, it's a large lump of glass and steel after all, then the speedo/drive cable/dash board/brackets with a light electronic one and of course the mirrors, replace them with something small and light

Steve

barra8 · Guru

brindabella wrote:
battery alternatives:

1. try removing it - see if the TTR still starts and runs, but you may still have problems with headlights at lower speeds, unstable voltage, more load on the voltage regulator;

2. replace it by making up and installing a suitably rated capacitor and zener diode as a "dummy battery" - may ameliorate some problems, but costs money and is one more thing to fail, and still the lights will be weak at idle speeds (and still no electric start);

3. replace it by a much lighter (but more expensive) lithium ion battery - save weight AND keep the electric starting convenience;

4. keep it standard - after all, its only a trail bike.

Bike will not run without the battery without bypassing the battery wiring via the Cdi unit (black box). Weak spark will result in removing it causing it not to start. Also some of the switches will need to be bridged (bypassed). Not to mention running the headlights ect. will become nearly impossible. That's not to say it can't be done.

So you have a better understanding of how the wiring works,the stator (AC magneto) part 1 in diagram (see below) which goes inside the rotor. This is primarily to charge the battery. It does this by going through the voltage regulator (rectifier) than charges the battery. The battery then runs everything else including the spark to coil (spark plug) via Cdi (black box).

1157366?AWSAccessKeyId=1XXJBWHKN0QBQS6TGPG2&Expires=1344470400&Signature=aJ%2FwuPQdnPgt5bhS1%2BwsB6U8HIg%3D

IMPORTANT: (warning) Do not attempt to bypass or tamper with the wires unless you know what your doing. TTr250's run AC & DC current and if crossed together the result will be a burning pile of useless wires faster than you can burn your hands to uncross them (don't ask how i know biggrin ). It's not like earthing DC to ground (small spark) it acts as an arc welder instantaneously burning wires before you know it.

Things to remember about AC current and DC current eg. AC stands for alternating current ie. AC magneto (stator)produces AC. It is then converted into DC current meaning direct current for the spark plug,lights ect.

AC is run because there is a thing called a pick up sensor inside your rotor case (see above diagram) . It gets tripped,sending a signal because of the magnetic field that the rotor has ( its magnetic). It acts as a trigger to tell the Cdi unit which then tells the coil the exact moment to fire the coil. Without AC and DC current it would not fire. AC is also used in switches ie. start switch,neutral switch,stop switch,clutch switch,brake,switch,etc.Confusing you??? I'll stop now lol biggrin biggrin It's hard to explain so yeah hope you get some of this.

Best way to make it lighter would be to get lighter rims remove anything that is unwanted or needed ect... As has Steve has mentioned..

If you want to remove the sprag clutch ect. for the electric start (although defeats the purpose of it) etc. you could do this easily and retain all the original parts eg.rotor part number 7 in Brian diagram and rotor bearing (number 9) if your model has one.

Also as brian mentioned you will have blank (plug) the whole where the starter motor would have been.

Ps.If you decide to take out the starter gear i won't say no to the gear lol smile

-- Edited by barra8 on Thursday 2nd of August 2012 11:58:02 AM