Backyard mechanic challenge

[rogerwa]

I got the sons a mini bike last year that came with a 2.5hp motor. It was kind of pathetic so I retrofitted it with a 6.5 Harbor freight Motor (got it for $103 and it started on first pull) and it basically brought that thing to life. You can feel the front wheel start to lift if you dare hit the gas too hard..

So now I have this little 2.5 hp horizontal shaft motor ( http://www.monsterscooterparts.com/97cc-baja-doodle-bug-mini-bike-engine.html ) that I would like to convert into a portable water pump. The motor is very light and runs great. I have done some looking around for affordable pump heads but cannot find anything that would seem to work.

Any ideas out there on how to find a inexpensive pump and how to mount it on this engine??

 

[mudslinging79]

Re: Backyard mechanic challenge

how many gpm are you looking for?

 

[BuzzStPoint]

Re: Backyard mechanic challenge

If the pump has a shaft.
You should be able to buy a coupler that will attach to the output shaft.

 

[rogerwa]

Re: Backyard mechanic challenge

I have an electric submersible pump that is rated for 1100 GPH with a garden hose sized output. This is about what I would want but for the application, I am not overly picky.

 

[foodfisher]

Re: Backyard mechanic challenge

Washing machine pump. Worked for my highbanker. The right sized belt was the only problem.

 

[mudslinging79]

Re: Backyard mechanic challenge

whats the flow on a mid to late chev 350 waterpump? i saw a setup with a motor like yours rigged to an altenater for charging batteries on an rv lot. you can find a pulley to fit your shaft that takes a fan belt, just a matter of fabbing up a mounting platform.

 

[rogerwa]

Re: Backyard mechanic challenge

I had thought about an auto waterpump as they would be plentiful, but I am not sure that would self prime. I would want it to slef prime if I stuck the suck end hose into something to pump out.

 

[Bigprairie1]

Re: Backyard mechanic challenge

Roger
There are two ways (minimum) to hook this motor up to a pump. Now, it appears to be a horizontal shaft output so I'll start with this:
1) Less preferred: Use a 'flexible' coupling to connect directly to a pump's input shaft. These couplings can be found and sourced on McMaster Carr and are easy to order/obtain...probably 3/4" shaft to....3/4" or 7/8" or? (ref. Pumps size)
2) PREFERRED: To use an offset belt or chain drive to hook this to a pump's input shaft. This allows you to 'gear' the pump...and the speed up or down depending on the results you want or need. You would not have that option with a direct drive connection (mentioned above). This gearing up or down is simply done by swapping out sprocket sizes or reversing the two on there. Personally I would get a couple of spare sizes to allow for more ratio change...and the chain is easy to resize accordingly.
In this system you can go with either fixed pump and fixed motor positions and simply take up the chain slack with an idler sprocket. OR:
Have the motor on a sliding base to 'pull' it away from the pump to take up the chain slack....your choice.
-Sprockets and chains for this can be bought at most industrial suppliers...I would go with something like a #40 chain or similar myself.
Now, for either of the above choices you will have to make a baseplate that mounts these two main units down. The motor mount will have to have an allowance for vibration control spacers or similar (again, McMaster Carr) so you don't shake the whole thing to death.
You will probably have to space the pump up somewhat as it is highly unlikely that it is the exact same height up from the base to the shaft.
Ok, thats my two bits for the moment.
All Good
BP

 

[thefairlaneman]

Re: Backyard mechanic challenge

I hope the kiddies dont ride the thing in public cause it is now illegal because of the extra power....lol