I found this web site that has parts that I believe will fit the yamoto 70. Has anyone had any luck finding mod parts? My 6yr old sons Bike stalled on me one day when I started it in the garage. I could not get it restarted. I have spark & fuel. I checked the compression and I had got nothing. Well I pulled it apart and it looks like the head gasket was leaking into the timing chain cavity. My thought was to add an 88cc big bore kit to help this atv get out of its own way in the sand. Well, Here is the site. http://dragonracingparts.com/engineparts1.html

 

And Honda parts are supposed to fit on a Yamoto?

 

i stand corrected
never looked but it appears elmo2resc is right. this is another honda clone. always heard this was
a yamaha copy, looks like just the plastic are the same. should be able to make run good. now if someone
would just come up with suspension parts

 

Not sure about parts for the 70. The front drive sprocket from a 98 honda z50
fits the yamoto 50 without any problems. These engines are a serious honda
knockoff. Do your research first though. I've been told by a dealer that many of the
gaskets interchange with the honda motors also.

 

Well, I have been E-mailing this guy & he doesn't know for sure if the parts will work. From what I can tell the bore and stroke of the honda and yamoto 70 are the same. The height of the cylinder is the same and the gaskets look the same. There were 2 different lengths of connecting rods on the honda. One was longer then the other which in turn makes the location of the pin on the piston different. I am trying to find out if the yamoto has a long or short connecting rod. I don't know the lengths of the two different rods so even if I were to measure mine it wouldn't help me. I think I am going to take a chance on ordering one of these kits if I determine the piston I need. Any more help would be appreciated. I will post the results after I order and attempt the install of the parts.

 

My concern was that the topic starter do his homework. Apparently he has. [img]i/expressions/face-icon-small-smile.gif[/img]
Now if those parts dodn't work, Depending on the results desired,,how about one of these whole motors?
http://cgi.ebay.com/ebaymotors/110cc...QQcmdZViewItem
They seem to be selling for not much $$$.

 

yes i saw those too.
and was thinking about putting one in a cheap knock-off quad
make a good pit quad

 

From what I have been finding out is that these engines are an exact copy of the '82 and later model ATC 70, 90 and 110. Some of the parts from a Z50J Honda (monkey) trail bike are useable too. Therefore, in theory the 88cc big bore kit would fit. As with modifying any engine (bore increase) you will need to upgrade the intake and exhaust. I would recommend an aftermarket carb for the ntake side for the factory Yamoto are know to be faulty. The exhaust I would modify one from a Honda CRF, or Honda monkey and make an original exhaust.

With that said, now all you have is the ignition. If you do you research, you will find that the aftermarket CDI Boxes from the Z50J will fit and work fine with these quads.

Honda piston and ring rebuild kits have been tested on these engines and they work just fine. I'm sure that Honda is really mad because there engine has been mass copied and the parts for most part are completly interchangeable. I bet you pick out the CDI, electric starter, and some other small parts from Honda and it would cost more than an entire copied engine. I'm sure that the engines aren't the same exact high quality as a Honda, but when you can replace the engine 4-5 times and not cost the sane as a high repair from the dealer, it seems like a nice alterative.

When I look at the 70, 90, 110 raptor style atv I see a yamaha body with a Honda engine and a mix of the drive train. From my experiance, the chain drive is higher quality than the drive shaft models that are commonly known for ackward noises and breakage. So in a way Honda does have parts for the Cheap quads.

If you buy one of these China brand quads, I advise that you take off the plastics and zip tie all the electrical connector and apply some electrical grease to them (before zipping). Lock tight all the bolts and change the oil regulary. I gurantee that you will get more than your money's worth from them. If you just bolt tires on and ride, expect to have problems.

 

Almost forgot, the only con-rod difference that I know is from 50-88cc is the same and 90-125cc are the same. With that said you can not bolt a 90cc OEM cylinder kit and think you will be boring your engine up to 90cc, for the parts don't work. all of the aftermarket parts for the Z50J are designed for the 50cc (heads, cams etc) and will not work with the 90cc above engines. I have heared that some cams will interchange with the 110cc engines, but is very hard to match.

I could be wrong about same displacement and having 2 length con-rods, but I know for sure the 90cc above are longer stroke.

 

How did you make out on your mod of your son's Yamoto 70's power? My 7 yr. old has the 2005 model and it can barely get rolling from a stop if there is any type of incline or slight bump in front of it. Other than that, we are pretty happy with it so far.