Sell the motor on ebay to buy a cr500 motor?

[JOHNDOE83]

Well, what do you guys think, I for a long time have wanted a cr500 motor in my EX frame and from looking on ebay a basic BARE running 400ex motor runs about $900.

I was thinking of selling my complete running motor on ebay for $1500. so I can buy a cr500 and do the swap.

I know a good 400ex can be had for $1000 with some shopping, but there is people out there looking for complete engine kits for karts and mini buggies or hybrids, I would be selling the complete wiring harness, carb, throttle cable, motor, battery, exhaust.

Basically you could unbox it, pore gas in it and hit the start button and fire it up in the crate when its delivered.

Do you guys think it would be worth a shot?

I also have a used tusk HD clutch kit on ebay for $25 free shipping.

[Duf6]

I think it would be cool,I would love to do that too but I still want my 400. If I ever get enough extra money I'd like to build one of those.

[CJM]

Cool yes, but last i recall they were vibration machines. Some tried (not sure outcome) to isolate the engines with some rubber bushings to act as dampeners on the motor mounts.

[Duf6]

Look in the hybrid section a guy in there built one, shows how he set his up and said vibration isn't bad. He's also got video.

[nelzar13]

from what i have heard is that the cr500 motor does not have an adequate counter ballence inside the engine. Its fine on a dirt bike but not for a quad. i was going to buy a 250r a while back that had a cr500 engine it and did a bunch of research about the counter ballance. i seem to remember finding something some where, were there was a guy who machined a counter balance and everything worked out great. but im sure he had access to a really good machine shop(otherwise it would cost the normal joe a fair amount of cash)

[JOHNDOE83]

Yeah thats about what I hear in the reasearch Ive done, I saw one thread were the guy used the rubber mounts and said it was way worse? He went back to solid mounts and just dealt with it in the end.

I think just to see what happens, Ill make a ebay add with video of the motor in the atv running with time and date, then if someone buys it Ill have to pull it out and crate it up.

But atleast then I can shop for a cr500!!!!

If it vibrates to much it wont be a big deal, itll be on my drag bike and I just bought a new trail bike so I only have to deal with the vibration during races, itll work out nice...lol.

Do you guys think $1500 is decent for a motor like mine? or should I ask for more or less, I dont I really wanna go lower then $1500.

[dariusld]

I just looked on E-bay and didn't see any selling for that much. Ranged from 400-800.

[Budweiserebel07]

One thing is for sure if it worked, you would have a head turner. I say gor for it man ! It would be pretty unique. :D

[honda400ex2003]

its a bit high priced for any 400 engine, id put the lowest you would take as a reserve and see how it goes.

cr would be pretty killer thats for sure.

look up isolated vibration dampers/tuned mass damper and see if you can figure out how to make one. if you need some help let me know. i will be getting my vibes book again this week and could probably work out a couple of different setups for you if you find out the weight of the frame and such and where you would like to put a damper on the frame.

http://www.me.mtu.edu/courses/meem3700/lecture_20.pdf

you might be able to read through some of that and understand what im talking about.

steve

[JOHNDOE83]

That is some crazy stuff, I thought the exhaust length to intake length formulas were complicated, but that stuffs wild....lol.

I think I read it wrong but may be close, its like using rubber type mounts or shocks or springs or even solid mounts, depending on were the most vibration is coming from and being dispersed throught the frame.

Like using a solid mount for the back, rubber in the front, and even a stretched spring attached from frame to engine or even a solid bar from frame point to frame point?

That would be my best guess, those equations are just way to hard....lol. And I dont have even 1/3 of the info required to fill in blanks....I got dizzy just looking at it...lol.

So those equations would basically tell you were to put that stuff?

Or is more about how a bomb shelter is built were they have springs supporting the building off the ground, except youd have like a steel plate attached to springs or shocks to absorb movement, then mounted somewhere on the ATV?

I know if you have a line attached to two points, like powerlines blowing in the wind, in high winds they can break from flaping around, BUT you can attach weight to the middle or ends and create less flaping in the breeze...lol.

[honda400ex2003]

usually they are solid mount "masses" that are used to take the vibrations out.

the problem with them is, there really isnt a set place to mount them. you can just figure out how much to use and go from there.

some of that is pretty useless for you, such as the la place equations and the matrix stuff. that was way over you head im sure but the typed up stuff is easier to read and get familiar with than having me try to explain it to you. lol

im just heading out, i will elaborate a bit more when i get back from dinner.

steve

[CJM]

I say you try and use some energy suspension sway bar polyurethane mounts. They sell them at pepboys and are meant to isolate the swaybar end links from the frame but work super well for lots of other stuff.

[jcs003]

Originally posted by CJM
I say you try and use some energy suspension sway bar polyurethane mounts. They sell them at pepboys and are meant to isolate the swaybar end links from the frame but work super well for lots of other stuff.

polyurethane is a great energy absorber. the problem is the engine is putting an enormous amount of torque through the final drive and the flexing of the bushings will magnify its effects. what is needed is a solid mount along with harmonic vibration dampening. another thing is knowing what frequency the vibrations are that cause the frame/mount fatigue failure.

the way to approach this is defining the vibrations mathematically and using a finite element analysis program to locate high stress/strain areas and engineer a solution to the weak points.

BUT, the differential equations needed to define the vibrations can be a handful.

my suggestion is to do research and find out who has done it and what was discovered by the guys who have done it and what can be done to make it better.

another thing, the cr500 motor is probably triple tha horsepower and might not be worth it if its not rideable. just my opinion.

[honda400ex2003]

and im not gonna do the diff equations for it lol. id do the damper but im not sure i want to mess with the rest of it.

it would take quite a while to do an FEA cad model on it, though, ill see what i can do this week on a makeshift cad model since i have to brush up on my solidworks program before starting my internship this week.


steve

[JOHNDOE83]

Well I put the ebay ad up today, this is a feeler just to see what happens.


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160590135369&viewitem=&sspagename=STRK%3AMESELX%3AIT

[trxPOWER]

good luck! i always thought it would work if somebody did it right. Do you know that guy mart300r on youtube? be built a counterbalencer for the cr500r engine, he talked about selling them as a kit, mabe you should try to get a holed of him.