# My Suzuki RM 250 conversion



## flinote (Nov 28, 2010)

Hi all:

This is my first post on the DIY EV Forums.

I thought I would post the details of my first successful EV project--a conversion of an older (1987) Suzuki RM 250 motocross. The avatar on the left of this post is me on the freshly restored bike with its EV conversion complete. I'll post detail photos in the next few posts, but here are a few links to youtube clips I did:

http://www.youtube.com/watch?v=KzZqFsq_UJ0

http://www.youtube.com/watch?v=0KfrJVtxu3Q&feature=related

http://www.youtube.com/watch?v=PheRn7kb6Kk&feature=related

http://www.youtube.com/watch?v=wEntvBbM1xY

--look for more soon

Bill


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## flinote (Nov 28, 2010)

Here's an image of the project, showing details on both sides.

Basic EV conversion specs:

Motor: Mars 0708 brushed DC, running @ 48 volts

Batteries: 4x50 AH AGM lead-acid, in a fiberglass box and installed in a quick-change mount (30-second turn-around time) 2 sets were built for this project.

Throttle: Magura twist grip

Battery meter: LED "state of charge" mounted on gas tank, available from Kelly Controllers

Controller: Kelly PM24301, 300 amp rating

Drive system: #40 chain with 13t motor and 76t rear sprockets

All-up weight: 250#

Max speed: 42 mph (limited by motor max rpm; designed for off-roading and a compromise between speed and climbing ability)

Acceleration: zero to max 42 mph in approx. 6 seconds

Range: 15-20 miles, depending on how hard you push it.


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## TerraRoot (Apr 9, 2009)

nice looker, any idea of the weight? must handle nice and sharp with the weigh up high.


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## flinote (Nov 28, 2010)

TerraRoot said:


> nice looker, any idea of the weight? must handle nice and sharp with the weigh up high.


The post just above yours lists all the specs, including weight. 

The quoted weight of 250 lb is probably too high; I'm sorry I didn't actually weigh the final product all-up, but instead I did a weighing at partial completion and added the weights of the items added afterward. 

In any case, it feels a little top-heavy at standstill--but as soon as you get going that impression disappears. l'm betting that a hot-dogger on this might complain if he tried to do a rapid changeover from one side to t'other--but otherwise no problemas.

Bill


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## Dcoxryton (Dec 29, 2010)

Hey nice job. I built mine on a 2008 KTM XC frame. I'm new at the forum thing, I'll see if I can attach some pics.
Question, you said you were using a PM24301 controller. That is only a 24v 300amp with Regen. The motor is 48V? 
I am using a ME0909 motor, almost the same. I am using less battery amperage (lead acid), 48V, t plan to go with LIpO4 batterys, when the economics work.
I have been trying to build my own controller, but have not been very successful.
I am ready to buy the KD48401 Kelly controller. Have you been happy with yours? Does the regen really make any difference?
Hope to hear from you.


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## Dcoxryton (Dec 29, 2010)

Sorry the pictures I sent were with my original motor. I have since changed it to the ME 0909. I'll see if I can find pictures of it.


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## flinote (Nov 28, 2010)

Dcoxryton said:


> Hey nice job. I built mine on a 2008 KTM XC frame. I'm new at the forum thing, I'll see if I can attach some pics.
> Question, you said you were using a PM24301 controller. That is only a 24v 300amp with Regen. The motor is 48V?
> I am using a ME0909 motor, almost the same. I am using less battery amperage (lead acid), 48V, t plan to go with LIpO4 batterys, when the economics work.
> I have been trying to build my own controller, but have not been very successful.
> I am ready to buy the KD48401 Kelly controller. Have you been happy with yours? Does the regen really make any difference?


Hi Dcoxryton:

Looks like a nice clean conversion--good job there.

Sorry about the misquote on the Kelly controller. It was a 48v 300 amp rating; looks like a lot of new models since then. Mine didn't have regen.

You need to be careful with regen, lithium batteries can handle it a lot better. You can really cook the batts if you set the regen too high. Not sure I'd bother if you're using SLA's.

I never had any problems with my Kelly controller; I wouldn't hesitate to recommend them based on my experience. 

Bill


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## YAMAHALOVER (Jan 7, 2011)

HEY. =)
how can this engines cost ? minimum ? how speed ?
how much was spend on tht ktm ?
how u charge the bateries ?
thanks


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## Dcoxryton (Dec 29, 2010)

The motor is a Mars ME0909 and costs about $400. The best motor would probably be the Agni for about $2300. (A lot more horsepower, but more current.)

Speed is about 40-45mph. 48V , 6 to 1 gear ratio, 19" rear tire, and bike weight of about 220 lbs.

You can buy a 2007 144 SX KTM everything is the same as mine ( 2008 505 SX) except the motor, for about $2500. Sell the motor for about $500.

The electric motor is about 400, the controller is about 400, the batteries could cost from 300 to 1000 depending on Lead Acid or Lithium. If you do all the work you will have about another 500 to a 1000 into it. 

I charge it with a 48V 12 amp power supply ( actually it is about 54V to charge)

That's just my experience. I am sure everyones else's story is a little different.

Hope that helps.

Don


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## Dcoxryton (Dec 29, 2010)

I got my Kelly KD72501 controller in and all works well. It does right at 40mph and gets there real quick. Only a small hitch so far. Since I am only using 14 amp hrs of SLA batteries, on hard acceleration the controller drops out due to under voltage ( current goes up voltage goes down)

I plan on next putting in either 40amp hr or 60 amp hour Lithium batteries, it's just some more money.


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## flinote (Nov 28, 2010)

Dcoxryton said:


> I got my Kelly KD72501 controller in and all works well. It does right at 40mph and gets there real quick. Only a small hitch so far. Since I am only using 14 amp hrs of SLA batteries, on hard acceleration the controller drops out due to under voltage ( current goes up voltage goes down)
> 
> I plan on next putting in either 40amp hr or 60 amp hour Lithium batteries, it's just some more money.


20 AH SLA's help a lot--but the lithiums will really "wake up" your project because they can put out so much more current without a big voltage drop.

Nice job!!

Bill


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