Will My Ryobi cs30 Engine Do The Job?

Whistle Tip

New Member
Feb 20, 2012
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Orange County, CA
I bought today, to start off my weed wacker bike build, a Ryobi cs30 30 cc engine. This is my first weed wacker/weed eater engine bike build.

Firstly I bought the weed wacker from craigs list for 50$. I have followed the postings for my area for more or less a month, and have seen the range for any working gas weed wacker fluctuate between 40-50$ dollars. But, this to me is no measure to see what I actually should have spent. Was 50$ for a 4 year old used (but working) 30 cc weed wacker worth it?

There over I will like to hear any input about starting a build. Already I have a bike me and my partner are going to use, its roughly 8 lbs give or take, so i would like to hear from any one with an engine similar; what they where able to achieve with the amount of cc's.
-Thanks.cs.
 

rustycase

Gutter Rider
May 26, 2011
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Yes!

it will work dandy!

mauritus just did a great write up on his chainsaw bike... trimmer, whatever! lol

You are gonna have SO much fun this summer!

Best
rc
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
Good luck with that build, Whistle Tip! (can I shorten that to WT or Tippy?)

I'm sure someone will say that 50 beans for a used wacker was serious buggery, but if it's in good shape, I say that's not so bad. Even if you found a new wacker for under 100 bucks, the new motors seem harder to DIY, especially since you live in CA. They want to discourage people from adjusting the carbs or modifying the exhausts.
The older motors are probably built sturdier, too.

2012 will be my fifth year running a 25cc Homelite motor on an old Schwinn 10-speed. I bought the leaf blower used for ten dollars. I don't know how old it was when I got it, but the fuel lines were falling apart and the piston top/combustion chamber were pretty crusty. I took it all apart, cleaned it and replaced gaskets and fuel lines. I think the power is acceptable. It runs a solid 25mph on level ground with no wind. I have to help it on hills and headwinds. It has a good 10,000 miles on it. It was gradually losing power this last year and I thought it was dying. But the screen in the exhast was plugged up. Runs strong again now.

A few years ago, I pulled a Mac 2816 weed wacker out of someone's trash. I just finally got around to messing with it (because I know that Homelite motor can't last forever). I have a bad habit of going overboard when I start working on something. I tore it all apart - piston out. At least you really know what shape it's in when you do that. This thing was barely used when the previous owner threw it away. The combustion chamber and exhaust port were really clean.

I got it all back together and just had it running in the garage. It idles and accelerates pretty good. The garage is below 40 degrees, so I didn't try to get the carb super fine-tuned. I might do a totally new bike build this year.
This 28cc McCulloch motor is built a lot like the Homelite. The cylinder, piston, connecting rod and bearings seem at least as sturdy.

So, what are you planning so far? What kind of bike? Are you mounting in-frame or rack-mount? Friction drive or chain/belt drive?
Are you planning on making it "pretty", or more go than show?
 

cannonball2

Well-Known Member
Oct 28, 2010
3,662
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Colonial Coast USA.
I have posted this before, the preferable Ryobi is not the yellow boom unit with the carb on the side, but the black boom with the carb on the rear. The late model Homelite style/Roybi is of lower output than the rear carb, and the rear carb is 31cc, this unit is sold by MTD. Both the older Homelite and Ryobi are excellent little engines, the Ryobi being 31cc and the Homeys both 25/30cc. The older 25cc seems to make the same power as a later 30cc. What it boils down to if I were going to build a WE bike I would look for and older Homelite 30cc or older Ryobi. All that said if you have the later Homey/Ryobi go with it. It will work fine just lower HP. Once done if you turn up an older Homey it will bolt in place of the later engine.
 

rustycase

Gutter Rider
May 26, 2011
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I've got a few trimmers here for conversion to mini-transport devices.
The other day, a Stihl string trimmer at the hardware store really got my attention! I used Stihl chainsaws professionally, years back, and they are such great engines!!! Of course they got bigger ones, but the little 27cc trimmer was listed at $160 and a salesperson told me they were about to go on sale for less.
It would be fun to see someone buy a brand new Stihl and build a mini-wing-dinger FD MAB ! I can't afford the brand new stuff, but it would sure be nice!
lol the mercedes of MABs ! :)
Best
rc
 

pocdragon

New Member
Apr 30, 2011
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RI
hey whistletip

usually most of us are pulling engines from the trash, and then refurbishing them to run well, so getting one that allready has the bugs worked out is a real plus

are you going to run a simple friction drive?

thats usually the best way to transfer the power out of theese little motors.

what sort of bike are you using?

my pride and joy is this skinny tire 24" road bike, it has a 25cc husquvarna engine on it from a whacker, i have achieved a top speed of 30.4 MPH with this bike on level ground, i live at sea level.



Good luck with your WASP bike build!
 

Whistle Tip

New Member
Feb 20, 2012
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Orange County, CA
Well I extend my many "thank yous' " to everyone who posted. From what I gather it would of been more economical to wait until I could get a free one, or one that is under 20$, which is funny i mention because yesterday i did get a free weed wacker from my uncle. Cripes! But I couldnt have known 2 days ago when i spent 50 fricken dollars on a fricken weed wacker in fricken garden grove i could of just waited!
On a less angering note, the new engine isn't working, and I can sooner build the bike with the ryobi engine. Speaking of which, to answer a dam's and pocdragon's questions:

As to what bike I am using.

I am using my partner's bike. so as of now i don't know the rim size, and/or the maker. We are only meeting up to work on it on the weekends so i will update the specifics then. But last weekend when we started it i remeber it to be around 20 - 24 inches, having a front suspension,and that its a 7 speed mountain bike, probably, like i said 8 pounds.

Our Plans.

We are going to do a friction drive. Yea from what I have read, (speaking of, I had followed pocdragons post "the orange peeler" that he posted a year ago or so last week; very cool) there is the most hp utilized from a FD. We really want to keep it simple, and realize that takes a lot of discipline oddly enough, but the benefit is hopefully less problems down the line, and we just want to ride. As it stands, and of course would love to hear about your guys recomendations, we are going to make a mount to the back wheel on the left, but it is going to be fixed, in other words it won't be like some weed wacker bikes that can be pulled up to disengage from the tire. But for when we want to break we will use the kill switch, probably on the back break lever (and we will have a throttle). I do though, see the problem of pedeling, so i would like to hear what mounts you all have, and but namely hear your input.

Thanks!.cs.
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
Every time I'm riding by a yard/garage sale, I stop and look for small-motored things for sale. Haven't found anything that way for the last few years. Here's how it went for me:

I was biking a few thousand miles a year on leg-power. Then in 2007 I thought a small motor would sure be nice for assist on windy days. I got online to see if anyone had done it. Boy, had they! I found motoredbikes.com and then this site. On my very block someone had a yard sale with a $10 homelite blower.
Since then, my brother-in-law gave me a 25cc craftsman wacker. Built very chintzy IMO, the cylinder "jug" only has 2 bolts. It was loose and rattling. I suppose it would have blown up it you run it like that for long. Tightened it down and it runs like new. Then my dad had an almost identical wacker with the exact same loose cylinder. He had already bought a 4-stroke craftsman wacker and said I could have the 2-stroke. Then I found a complete 28cc McCulloch in the trash; just got that running. That makes 3 extra motors (whole weed wackers, actually), although the craftsmans seem kinda puny. Maybe they have just as much power.

Anyway, if you keep your eyes open, in time you should be able to find motors faster than you burn through them.

A rack mount might be the easiest for a DIY friction drive. My mount is very similar to pocdragons - basically clamped to the seat stays. I would highly recommend a disengage system of some kind. Since you obviously have to "bump start" these things, and they often require fiddling with the choke and/or carb screws, it would be very frustrating to have the drive always engaged. Probably unsafe, too.

I planned on having a "kill" system, but didn't need it. My motor dies on its own when the throttle is released all the way. In a panic stop, with the gas off and brakes on, the motor doesn't hurt stopping ability - might actually help.
 

maurtis

New Member
Dec 14, 2011
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Kyle, TX
I did a friction drive build using a 30cc Ryobi TP30, which should be similar to yours. I would have waited for one of the older 32cc Ryobis, but this one turned up free on Craigslist and I could not resist.

Mongoose XR-75 MTB Weed Eater Friction Drive

The motor worked fine and needed only a little help to get rolling, bump started fine, and with the 1.25" roller did not need much help getting up small hills unless I was in a hurry, lol.

BUT... having a scissor lift to disengage the motor when stopped (or if I wanted to run the motor in the garage, for tuning and such) was very nice. Since we have a lot of stops in my neighborhood, it made the ride much more enjoyable being able to not have to restart the motor every time I took off. I really wanted to be able to use the stock clutch, but it self destructed very early just like everyone predicted, lol.

Good luck, and have fun with the build!
 

pocdragon

New Member
Apr 30, 2011
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RI
nice bike A-dam!
usually people think its taboo to make a WASP out of a skinny tire bike, but i see it as more efficient,although you donot have the footprint you would on a wider tire so slipping in corners, sand and wet spots can be tricky

also, whisletip:

thanks for the props, i take alot of pride in my work.

seeing how your using a mountain bike, i reccomend you swap the rear tire to a street tire with a smooth tread, if it isnt already. it will be easier for your roller to stay on the wheel, and will increase your efficiency and top speed.

i reccomend against a solid mount,
coasting on a bicycle is one of the nicest things about it, if you just kill the engine without a release valve on the cylinder or somthing clever like that, the engine will just act as a brake and slow you right down. sure its safe, but not as efficient.

go with a scissor clutch, they take a bit of fiddling, but they are dead simple
i made mine with a big gate hinge. its mintxct2
 
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a_dam

New Member
Feb 21, 2009
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Momence, IL
Thanks pocdragon!

Big, smooth, skinny tires sure do roll easier. I tried knobby tires on the rear of that 10-speed for a while. All that extra rubber should give a lot more wear for these friction drives. But the knobs also give a lot more noise and vibration. And my smooth rubber roller grips best on a smooth tire.
My tire wear ain't too bad anyway. A $12 Walmart tire probably lasts about 1000 miles. I was spending about twelve bucks a day on beer, so now that I'm giving my liver a vacation, I can afford a few tires a year.

Smooth is definitely the way to go for me. I only use the motor on paved roads, though.
 

BarelyAWake

New Member
Jul 21, 2009
7,206
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Maine
If you've a friction drive but would still like knobbies, you could check out the Kenda Kross Plus (26x1.95 $10);



I use 'em on my mountain bike MB for reduced rolling resistance & prolonged wear. Obv they're a compromise, you'll not stop as well on dirt/grass (same as any street tire) & they feel a lil weird on asphalt while turning as you make the transition from a slick to a knobby (flex), but that's no different than any other knobby. One of the things I like about them is the smooth center band is the same thickness as the knobbies, making them significantly thicker than some other street tires I've tried... tho that MB isn't a friction drive so I dunno how they'd hold up to that ;)
 

cannonball2

Well-Known Member
Oct 28, 2010
3,662
143
63
Colonial Coast USA.
I have tried several different types of tires and found the Duro 2.125 cruiser tire to be the best suited for my FDs. Last over 1200mi, offer a good cross section for grip and are smooth rolling. That said my 97cc 4strokes have power to spare and rolling resistance is not an issue. I get the best grip and ride at 30psi. I would think with the smaller engines a 1.95 smooth tread would be ideal, like a Kenda city slick. Has a good cross section and low resistance.
 

a_dam

New Member
Feb 21, 2009
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Momence, IL
That's just the type of tire I'd get, Barely. But my old 10-speeds are 27 inch. Seems like that size has the fewest variety of tires available. I was thinking of trying a 700c on the rear because my brake calipers should still reach that slightly smaller rim, and the tire selection has to be better than 27in.

One of these days I'll find some tires with a thicker cross-section and I'll buy up a bunch.

Speaking of Kendas - They've been pissin me off lately. Seems like all the kendas from my LBS have belts that go bad before the tread wears down. Anybody else having this problem?
 

BarelyAWake

New Member
Jul 21, 2009
7,206
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Maine
My bad, I didn't notice you've 27s sorry man :(

hmm... I've always run Kendas on my mountain bike MB & I've never had a belt issue, but perhaps it's a specific tire that has that problem? Mebbe I've just been lucky? *shrug*
 

rustycase

Gutter Rider
May 26, 2011
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Left coast
I surfed through a bunch of the bicycle forums for a while, checking on their opinion of different things that might be applicable to mabs...
I came away with the overall feeling that Kenda was best known for most reasonable prices.
Sry, I just don't know of a suitable option to run on a 27" rim... :-(
Best
rc