I've searched the board and cannot find the answer. Belt #7KF-46241-00-00 is the more expensive one and sells for $75. And belt # 7KF-46242-20-00 sells for something like $25. I would like to know the sizes of these belts.
The YS-828 belt sizes are LA-37 (4L370?) and LB-36 (5L380?)
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The original equipment Yamaha belts are/were made by Mitsuboshi (MBL in the USA) and are fully wrapped with a threaded fabric and have an impregnated rubbery coating (not bare edged or uncoated fabric belts). They are labeled "set free", and "heavy duty for reverse bend."
The LB-36 has the orange label, and has the number 271 printed on the inside. Most importantly they are thinner than most other belts on the market (MBL's "L" represents a "narrow" belt class). The narrow belts excel on the snowblower's smaller size pulleys and are specially designed for back bending and use with idler pulleys. Mitusoshi does not import the narrow "L" belts into the North American market.
The LA-35 belt has the black label (see below) and has the number 291 printed on the belt's inside.
So the thing to remember with Belt sizes is that the designation "A" or "B" is a reference to the width of the belt (classical sizing). The "35" or "36" does not correspond to an eact measurement of the inside or the outside circumference. The "35" or "36" is just a reference number. 4L and 5L belt sizes (automotive belts) are measured from the outside. There's a conversion factor from "automotive" belts to "classical" belts: For belt lengths in this range (<200") the inside circumference of the belt is typically 1.5 to 2" less for a 4L belt, and 1-1/2" less for a 3L belt.
In the automobile belts, the "4" and "5" in 4L and 5L corresponds to the belt's outer top width (not the outside circumference) and is expressed in fractions of one eigth of an inch. So 4L= 4/8 inches (or 1/2" or .5 inches). 5L=5/8" or a top width of .62".
"A" or "4L" belts have a thickness of .34"
"B" or "5L" belts have a thickness of .44"
The "L" stands for the "included profile" in automotive belts but not in the MBL snowblower belts that we use. (see included profile in the image below). Included Belt Angle for all above belts is approximately 40 degrees. But don't confuse this with the "L" that is on our "LB-36" snowblower belts.
How to read V-Belt numbers
"Classic" v-belt numbers start with a letter identifying the cross section, A through E - see V-Belt Dimensions below. "A" series belts are the most common. The number following it the "A" or "B" is a reference size (this is not the size that you would find is you measured the inside length in inches). The outside length (circumference) is typically 2 inches more than this reference number and the inside circumference is 1 inch more than this reference number. An example would be a belt designated "A35"; this belt would measure 36" long on the inside circumference and 37" outside; the equivalent of the 4L460 above.
Automotive belts start with either 4L (12.5mm wide) or 3L (9.5mm). The number following it is the outside length of the belt in tenths of inches. The inside length of the belt is typically 2" less for a 4L belt, and 1-1/2" less for a 3L belt. An example would be 4L460, which would be 46" long outside, 45" inside.
"4L" and "A" series belts are ussual close enough in size to be interchangeable, even though automotive belts are technically 0.3mm narrower.
All v-belts have a 40° angle between the faces, except the V series (aka "Harvester" or "Wedge" belts), which have a 30° angle between the faces.
You will notice that the inside edge of the belt is wider than the base of the V in a v-belt pulley - the belt touches the pulley only on the sides.
Note: Much of this I found (stole) from the web and I don't take any credit for it.
Conclusion: if you want the exact belt that came on your Yamaha snow blower your best bet is an original equipment replacement belt from a Yamaha dealer ($). If you aren't too fussy you can find something pretty close (although thicker) that will probably work just as well and save you a few dollars.
Mitsuboshi's contact information in the USA is:
601 Dayton Road, Ottawa IL
Here is the description of the "L" series belts made by Mitsuboshi:
Thin Wrapped V-belt Characteristics:
Thinner than standard V-belts, with higher bending properties. Can also be used for back side bending.
Standard: Has excellent flex resistance. (the LA-35 is a black label).
Orange: Has excellent flex and shock resistance. (the LB-36 has the orange label).
Gold: Has even higher flex and shock resistance than the orange type.
Super gold: For high power rating, featuring aramid cords.
You can select the belt most suitable for your application.
Bare Back Type: Clean power transmission is achieved with little dispersion of rubber powder.
This is used for clutch drives.
Applications: Agricultural machinery, general industrial use (light duty), clutch drives
http://www.mitsuboshi.co.jp/english/ourpro/index.html Belt types: LA, LB, LC
Good Year Belt size: Drive Belt; a-36 [ 1/2" -- 36" ID. ]
Auger Belt; b-34 [ 5/8" -- 34" ID. ]
Price in Newfoundland between $10.00 & $18.00
I have no problem with these belts, works fine for me. Thanks! and good luck with your search.
Merry Christmas to every one!
I'm running the Ys=828 and purchase aftermarket belts on Amazon with little luck. They never seem to be the right size. The $15 price you quote sounds reasonable to me. Especially if its the true Yamaha belt. Those are ussually expensive.
All V belts are metric so it will be easy to find the proper size for the belt
V belts are made with either man made Nylon or Kevlar thread and has rubber molded around the thread bundle.
The new V belt is the proper size if the crown of the V belt is flush with the pulley sides not below or above them.
A size V belts are 1/2 inch/12MM wide at top wide width
they are .31 inches tall/ 8MM from the bottom edge to the top edge
B size V belts are .66 inches wide/16MM
they are .41 inches tall/10MM
C size V belts are .88 inches/22MM wide
they are .53inches/14MM tall
I would simply chat with the canadian retailer who is a memebr here and ask which tyoe of belts you need to obtain the proper cross reference size WHICH IS UNIVERSAL, AS ALL V BELTS ARE METRIC JUST LIKE BEARINGS.
I need help also. I have a ys624t and ordered thr original belts from yamaha and having a hard time getting them to work. Seems like the auger belt is too short. Can anyone post a pic just so i can confirm that im not doing something wrong???
Yesterday I also broke the LB36 V-belts in the middle of a storm ...
after reading this tread, I tried to buy the Mitsuboshi belts, but I did not find any seller who had both belt (LB36 and LA37) and that would guarantee me both were orange labels. So by calculating the various shipping costs for different sellers, after losing all day, I decided to buy them original Yamaha Belts on www.partzilla.com for a total cost including shipping in Italy of $ 103 ...
from this experience I realized that it is good to always have spare Belts in the garage
Partzilla took too long to provide me with the original belts, so I canceled the order and bought the Mitsuboshi LA37 and LB36 in France. I compared them with the old originals and I can confirm that the originals are exactly the Mitsuboshi orange label. I have already fitted the new belts and tried the snow blower with an excellent result!
I am satisfied with the purchase and have made clarity on these mysterious belts.
I think that for a while I should not have any problems with the belts