Still want to argue about rubber mounting?

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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
Ive got a 10hp Kohler that is a war horse on an old John Deere lawn tractor.

My newest riding mower has a single hole 20hp Kohler and it runs great also.

Dang good engines.
 

HDCowboy

Member
Jan 3, 2015
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Texas Gulf Coast
I wonder why you don't hear about no Harley frames breaking? You see those engines dance all over in the frames and they don't break! I think its a little more due to either cheap frames or bad mounting!
 

Chainreaction

New Member
Dec 14, 2014
159
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Tulsa OK
The reason you don't hear about Harley frames breaking is that they aren't clamping rubber around the frame. Some of their mounts are circular with rubber sandwiched in between the outer part of the mount and the inner part, same basic idea as mounts that are two plates with rubber sandwiched in. There is no comparison between a Harley mount and putting rubber between the frame and clamping action of MB motor mounts.
 

curtisfox

Well-Known Member
Dec 29, 2008
6,046
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minesota
It's off the net. And it's a 16hp iron block with a roller bearing crank. NOT a 4hp. Lol!
I wish I still had one of these. Flat. Out. Indestructible.
I have some real good memories of the engine that made me look this pic up for another thread. Check out "Gearhead Memories" In tavern
Now that i look closer the cover is bigger,not seen a red one that big. I had one sold it they are sought after for garden tractor pullers,they get like 60 hp out of them. I have 4 case garden tractors that have 12 & 14 hp in them,will be down sizing on them also only need one good one...............Curt
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
Now that i look closer the cover is bigger,not seen a red one that big. I had one sold it they are sought after for garden tractor pullers,they get like 60 hp out of them. I have 4 case garden tractors that have 12 & 14 hp in them,will be down sizing on them also only need one good one...............Curt
60hp? Wow.
I know they are one seriously tough engine from learning and modding the one I had, but I KNOW we never got anywhere close to those numbers...
But it does not shock me at all. That Iron block and roller bearing crank made it able to stand up to a bunch of ignorant kids with horsepower dreams for almost 5 years of SAVAGE abuse!
 

curtisfox

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Dec 29, 2008
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Yep they are fun to watch. I get to see them every year when i visit my brotherinlaw in Wisconsin,awesome power.............Curt
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
I wonder why you don't hear about no Harley frames breaking? You see those engines dance all over in the frames and they don't break! I think its a little more due to either cheap frames or bad mounting!
there's a Huge difference between a well engineered frame and a backyard hack with a rubber hose trying to call it a mount... have you ever seen how tough these Harley frames really are? we're talking about tubing with 1/8" to 3/16" wall thickness and the head stock is closer to 5/16" wall thickness, The older ones used forged headstocks welded into the frame tubing as well as forged mounting pads for the engine and transmission. I got an old Ironhead frame at the shop that's stripped all the way down and that thing is Rock Solid. You can definitely feel the difference between a *** cruiser and a Harley on the road as the Harley is just as solid as it can be and makes everything else feel like a toy.

Being a fellow Harley rider I'm sure you already know this, but this is for the newbs that want to point out Harley rubber mounts their engines... Yup, they do now, but until Very recently All their engines and transmissions were solid mounted with the exception of the Dynaglides. The Sportster finally got rubber isolation mounts just a few years ago, but I really like my solid mounted sportster myself. Even the sportster frmes are tough as nails and weigh twice as much as most Japanese cruiser frames.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
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memphis Tn
there's a Huge difference between a well engineered frame and a backyard hack with a rubber hose trying to call it a mount... have you ever seen how tough these Harley frames really are? we're talking about tubing with 1/8" to 3/16" wall thickness and the head stock is closer to 5/16" wall thickness, The older ones used forged headstocks welded into the frame tubing as well as forged mounting pads for the engine and transmission. I got an old Ironhead frame at the shop that's stripped all the way down and that thing is Rock Solid. You can definitely feel the difference between a *** cruiser and a Harley on the road as the Harley is just as solid as it can be and makes everything else feel like a toy.

Being a fellow Harley rider I'm sure you already know this, but this is for the newbs that want to point out Harley rubber mounts their engines... Yup, they do now, but until Very recently All their engines and transmissions were solid mounted with the exception of the Dynaglides. The Sportster finally got rubber isolation mounts just a few years ago, but I really like my solid mounted sportster myself. Even the sportster frmes are tough as nails and weigh twice as much as most Japanese cruiser frames.
The only thing I would add is that the high-frequency vibration of a chinadoll is MUCH harder on frames than the rocking couple of a V-twin despite the much larger displacement. Our frames have much less mass to absorb it as well.
It's the buzzing that kills stuff for us even though it's only 66cc
 

curtisfox

Well-Known Member
Dec 29, 2008
6,046
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Hi Dale
Yep got mine off a old rotary mower at a sale $50 turns out the mower was all warren out so scraped it and saved the motor love it. Had it blasted and painted the block bright Yellow with black trim, that will be about the bigest engine i will use...........Curt
 

MadMaxed

New Member
Feb 15, 2015
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Florida
Dont mount with rubber. Altho its your life. If you value it or not is up to you.... Going WOT and your peddles drop out from under you doesnt seem to be the kind of event you would want to celebrate.Listen to these guys.
 

fatdaddy

New Member
May 4, 2011
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San Jose, Ca.
We all tried rubber mounting when we were newb's, unless ya found this site BEFORE ya started yer build. It just kinda sounds like common sense to rubberize the thing to quite vibration. WELL, I didn't find this site for a few years after I started building. I did figure out that soft rubber wasn't the answer, so I tried using tire sidewall rubber which worked a little better. I still couldn't figure out how to make it ride as smooth as a Honda. Then I found this site and the answer is, IT WILL NEVER RIDE LIKE A HONDA,Cause its a not so well balanced Chinese 2 stroke. Some run smoother than others, but they all are gonna vibrate to some extent. GET USED TO IT, or buy a Honda.LOL. sometimes after riding for an hour or better I can't feel my balls anymore and my arse goes numb too. I try to take a break before my hands go numb because it's just too dangerous if ya cant hold on to the bars..duh. If ya can't hang with a little vibration, Buy a factory built motorcycle. BUT NEVER RUBBER MOUNT YER ENGINE, It dont really work.
fatdaddy.usflg
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
We all tried rubber mounting when we were newb's, unless ya found this site BEFORE ya started yer build. It just kinda sounds like common sense to rubberize the thing to quite vibration. WELL, I didn't find this site for a few years after I started building. I did figure out that soft rubber wasn't the answer, so I tried using tire sidewall rubber which worked a little better. I still couldn't figure out how to make it ride as smooth as a Honda. Then I found this site and the answer is, IT WILL NEVER RIDE LIKE A HONDA,Cause its a not so well balanced Chinese 2 stroke. Some run smoother than others, but they all are gonna vibrate to some extent. GET USED TO IT, or buy a Honda.LOL. sometimes after riding for an hour or better I can't feel my balls anymore and my arse goes numb too. I try to take a break before my hands go numb because it's just too dangerous if ya cant hold on to the bars..duh. If ya can't hang with a little vibration, Buy a factory built motorcycle. BUT NEVER RUBBER MOUNT YER ENGINE, It dont really work.
fatdaddy.usflg
my major vibe issues were greatly reduced when I bought my first dax GenIV lowers, miles and miles, no more serious duffle bag numbing, the south end of me being a north bound mule not all tingling and numb and hands still feel good after a 25+ mile ride.

The latest rose326a GT5 build is just as smooth....

All my old BGF engines w numb all the things descri ed here in a 3-4 mile ride if the revs aren't kept below that jackhammer stage some of them hit.

I tried the rubber on the old BGF air hammers and just broke studs until I found this forum a month or two after my first build.
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,293
294
83
Santa Barbara, CA
Fatdaddy---I agree, if you can't handle the vibration then get a real motorcycle or an electric bike. I use grip gloves so my hands don't get too numb and my fingers are still free to grab things easily. I still use rubber for the chain tensioner mount and under a clamp for my expansion pipe just to help it stick better and to save the paint on my frame but I don't use it for the moter mount.
 

msrfan

Well-Known Member
Sep 17, 2010
1,808
120
63
Southern California
Exactly right. My first 6 china girl motors were smooth enough to enjoy a long ride, but then I got 4 in a row that shook terribly. Rubber mounting didn't help. I was building them to sell but wouldn't let them go like that. Finally I learned how to balance the crank/piston assembly and got one to smooth out nicely. I still have a couple of kits left and I'm afraid I'll eventually have to balance them as well.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Exactly right. My first 6 china girl motors were smooth enough to enjoy a long ride, but then I got 4 in a row that shook terribly. Rubber mounting didn't help. I was building them to sell but wouldn't let them go like that. Finally I learned how to balance the crank/piston assembly and got one to smooth out nicely. I still have a couple of kits left and I'm afraid I'll eventually have to balance them as well.
Yep I have 3 engines that need crank truing or just a more modern crank like the one that are coming in the newer better balanced engines, the rest on the engines are good but the vibes at the high rpms are limiting and horribly uncomfortable.
 

fatdaddy

New Member
May 4, 2011
1,516
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0
San Jose, Ca.
The only place I still use rubber is under the gas tank, and thats mainly just to keep it from sliding around. I rubber cement a strip to the top tube then rubber cement the tank to that. It dont move at all.
fatdaddy.usflg
 

Tyler6357

Well-Known Member
Mar 15, 2012
1,293
294
83
Santa Barbara, CA
The only place I still use rubber is under the gas tank, and thats mainly just to keep it from sliding around. I rubber cement a strip to the top tube then rubber cement the tank to that. It dont move at all.
fatdaddy.usflg
I use rubber under my gas tank too, but don't tighten it so tight that it doesn't move, you know, in case I get in an accident and my "family jewels" hit the tank, I want the tank to move. :)