Weed eater engine conversion

pistnbroke - I was going to use a a motor between 30 to 40 cc. I have a watersnake 34lb motor housing.

 

So you use the original flex cable and shaft and haven't had any problems with it?
I am assuming you just cut the flex shaft to suit the size you needed?

Also in order to get these motors to go faster you can do modification to the ports, gut the exhaust as well as add a larger carb to them around 11mm to get a lot more power. I am in the process of building a rc boat out of a weedy motor and they have been known to do around 40mph so I am hoping to get something around 6mph with my 30cc ryobi when I finish building the mini mud motor which will push a 10' inflatable. I have a 35lb thrust motor and a large battery but it dies out so quick and I am only getting about 3mph with the trolling motor for about 45min run time.

In order to water proof the electronics you can use a product called corrosion X which you soak all electronics in and let them dry and then they are waterproof. They use this on a lot of marine applications.

Also as far as the props go take a look at rc boat props there are tons available around the size you are talking about 3 1/2" and they can be sharpened and formed to better suit the application.

 

sounds like your battery is no good you should get longer than that as it only draws about 30 amps .....2-3 hrs out of a 110 ah battery ....your speed is limited to 3 mph by the prop pitch and motor speed ...many people run these 12v 36 lb motors on 24v for greater efficiency without problems ...

why dont you just hang your r/c boat prop on the end of 5 ft of 1/4 rod out the back of the boat ...no tube or bearings ..works fine .....

 

Yeah that's what I was thinking about the motor and the amount of time I get out of it. I get decent speeds for about 45 min then it dies to a slow crawl and when go to charge battery it is about 50%. I am planning to return it, I bought it new.

Funny you say that I was thinking of trying something similar but not exactly as you explained.
More like using the prop but still have it look like a mud motor.

 

Could you post where you can purchase 3.5" R/C boat props

Can you post a link to some of these 3.5" R/C bpoat props? I'd be very interested to purchase a couple of these.

Thanks -

Mark

 

How about this prop

It is from a 12V trolling motor with 18lbs of thrust. It is made of plastic, has 3 blades and appears to be a counter clockwise rotation prop which is what we need. I do not know the size of the prop but from pictures I've seen of the motor it goes on, it is quite small. It is made by a company called sevylor. Here is a link. Who wants to try it out? If anyone can find out more info on this prop, please post it here.

http://www.shipstore.com/SS/HTML/SEV/SEVPROP.html

OK, here is a better deal on the prop - $1.07

http://www.sevylor.com/Replacement-Propeller-P1910C45.aspx

Mark

 

yes mark looks worth a $1 try but it would go at 1000 rpm on the electric motor ..will it stand 7000 rpm and will it produce 7 x 18 lb of thrust ? ie bog

The props I posted pictures of were on www.ebay.co.uk search on rc boat props ...but the chinese have there left and right rotations mixed up to go by the photos so watch it ...

 

The best prop as far as a metal one like used in rc boats for this type of engine would be either a prather 275 75mm or prather 280 80mm you can find them online for decent prices just have to look around. Most 3 blade props won't work very well, the two blade props work best unless you have a decently modified engine you could get away with using some 3 blade props. http://www.whobbies.com/blowoutspecials.php is having a blowout sale and the 275 prop is $5 plus shipping while supplies last.

To get the most out of them you will have to either sharpen and balance them yourself or you can buy them already sharpened and balanced costs a bit extra.

 

The guy at whobies is very difficult to deal with ( dont upset him ) The web site is very old fashioned and difficult to use .
if you are in the usa you must phone in the order...( would be nice if it said that on the site )
If you are outside usa you should open an account .( the clicky bit for that is very small and not on all pages !!!).credit card details etc and then e mail him with your order as you cannot add the blow out items to your cart ( real up to date and good for business that is !!!! )
He says the props are fine for the weeed wackers but I think he means in a model boat and they have stronger props at about $13...good luck ..I have ordered 2 as I bought a new wacker fo $50 the other day with the string head missing .....
Now be good and talk to the guy real polite......he is making so much money he wont take any ****.

 

Like I said these are meant for rc boats but work well with weed eater powered motors. The one you ordered is the smaller of the two I recommended and I am not sure what the results are going to be because I only know they work very well on rc boats and made a recommendation because of the post that said a 3-3.5" prop worked well.

Remember to get the most out the prop you will need to sharpen and balance it to get maximum results.

I don't see a problem with having to call to order a special blow out product or having to make an account to use a credit card, lets not make a big deal of something where your getting a nice break on a product where typically you'd be paying a lot more. No need to bad mouth people.......

Let us know the results of your finding on the props when you get a chance to test them.

 

no one is bad mouthing them....you missed the point that I am in australia ...I have an account with them usa shipping adddress Amex card and they still carnt do it ..now if they took pay pal ....

I am not getting this prop thats the point and good luck to anyone outside the USA who tries to get one...

 

If I took it wrong I'm sorry I was just calling it as I saw it.
I wasn't trying to be rude or anything.....

That sucks they don't have a way to send it to you I'm not sure why that is.
I will see if I can find someone more local to you that will have the props I recommended. I have a few people I talk to out there. I'll get back to you soon.

 

Did I see some flying pigs go by?

Pistnbroke bought a weed eater to make into a mud motor? I thought you started at 5hp and went up from there. Can't wait to see what you do with the smaller motor.

I think this is a first isn't it pistnbroke?

Mark

 

Well Mark when I am spending money I expect service . In my own business I give good service to my customers even the dick heads.
In the end I sorted it by ME asking if they took pay pal ...its not on the web site anywhere and they do take it so I sent them the money and maybe we get the goods shipped to PA.
Where have you seen a site where you cannot add goods to the cart ?
Why do you have to struggle to find a clicky to open an account ?
Why does the search not bring up goods when correct code is put in ?
why does the owner not understand he would be a richer fatter american if he had a user friendly site?...took 3 days to finally get the order through.

I rest my case.

 

Wow, I think you missed my sarcasm. I had no comment on the dealings with that horrible company, I just can't believe you are making a weed eater mud motor? I thought you only made motors that started at 5hp and went up from there. Nothing more, just giving yousome ****.

Mark