testing the Yerfdog

[metalstudman1]

Figured I'd post a short vid of the wife trying out the new mod's to her Yerfdog-
http://www.youtube.com/watch?v=et2r_Fwwy74
The old swingarm had almost eat it's way thru the swing brackets. I moved the disk brake to the drivers side to allow the exhaust to go on the passenger side out of the way of the CVT cover. Now I can pull whatever cover off without having to remove something else first. Up-graded the small brake caliper with a larger motorcycle one.Used a 1-1/2" hex axle this time (kept bending the HD axle). Overall outside rear tire width is now 59" or 44" to the inside of the hubs(about 11" over stock) Next mod will be the hiem's at the frontend but waiting to find the right shocks first.
I'll post some pic's of the mod's if anyones interested

[olderthan]

looking good

[Rarerat]

Very nice

[metalstudman1]

Here's some pic's of the finished configuration and what the original brackets looked like after hundreds of hours of abuse! and where the new brackets went- I was lazy and made the swingarm straight instead of the tapered design it came with- the idea was that a wider stance would last longer, the arm is still 24" wide.

[roysheepdog]

how long do the shocks need to be on the front?

[metalstudman1]

12" eye to eye, I've tried multiple types trying to get the right feel for my wife. I can't afford to step up to a adjustable gas shock yet.

[metalstudman1]

I shortened a vid of a GPS run for top speed
http://www.youtube.com/watch?v=HU7hCoCMAjk

[Rarerat]

Originally Posted by metalstudman1

I shortened a vid of a GPS run for top speed
http://www.youtube.com/watch?v=HU7hCoCMAjk

Dang that thing is running strong. I think ours only runs about 31. My daughter & I were out in it together today, and I was telling her how much I like her buggy I just wish it had a bit more power to get up some of the longer sand hills.

I am sure you probably posted it before but I can I ask what engine mods you have done?

[metalstudman1]

This is a $50,(approx. 1000 miles on it) craig's list trashed scooter engine!!! STOCK AS THEY COME. I did build the exhaust-muffler came off a 250 motor- Doubt that it gave it any performance advantage. The GY6 125 engine before it was stock as well and it did 40.1mph with the 16 tooth drive sprocket

[Rarerat]

Thanks Metal, I will have to look at which sprocket she has on hers. Also what wheel & Tire combo are you running on the rear? I havent really found any tires I like to fit the 8" wheels and cant find any 10" wheels with the right 4 on 110mm bolt pattern.

[metalstudman1]

You should have a 13 tooth drive sprocket and I quit hunting down the 110 bolt pattern and bought some golf kart wheels and re-drilled them by hand with no problem.(made a template from the stock hub)
Rear tires on my wife's are 22" x 11" x 10"

[Rarerat]

Great job, Thanks.

I did notice that Rocky Mountain has a set of 22x11x8 Duro's listed.

http://www.rockymountainatvmc.com/pr...FamilyId=17501

I am just not sure if they will be to wide for the stock Yerf rear wheels??? Plus those will be quite a jump in height from the stockers, I am still just a touch worried they will kill the bottom end on those long steep sandy hills. Right now it will bog down quite a bit on some of the steeper hills, especially when the both of us are on it.

[metalstudman1]

There's no doubt the larger tires will take away from hill climbing. Yerfdog stock wheels are 8"+/- wide. A little too narrow for that 11" tire in my opinion.You already know that if you increase the tooth count on the axle it would climb better but the top-end would go down.(there's not alot of space between the engine and sprocket to do a whole lot) One of the other guys will have to give you some advise on getting more torque from the engine.

[ckau]

Originally Posted by Rarerat

Thanks Metal, I will have to look at which sprocket she has on hers. Also what wheel & Tire combo are you running on the rear? I havent really found any tires I like to fit the 8" wheels and cant find any 10" wheels with the right 4 on 110mm bolt pattern.

take a look at these http://www.itptires.com/2010-wheel-chart.htm

I use the 9x9, 3+6 offset, 1/110. part#91R411 for the rear. most any atv tire comes in that size so your choices are not limited as to tread.
A 22" tire won't hurt the bottom end with stock 13/31 gearing and will increase top end a touch.
To give you a general idea...
I use a Kenda klaw XC K533 for general purpose/trail, 22/11/9
a ITP holeshot 19/10/9 if it's not real muddy or wet
and a Duro HF245 20/11/9 on the hard track
all of these are on itp 9x9 wheels and they work fine.

[kliff]

Start with UNI air filter, carb re-jet,NCY "red" CDI, "orange coil", iridium plug, and exhaust... 13/39 sprockets

Or just to "test the waters," 1500 rpm clutch springs, 1500lb torque spring, 12gr Dr Pulley sliders( possibly 11gr or 10.5's) Then add the engine mods on!

59mm BBK & a 60mm crank(+2mm stroker), some port work, A11 cam, 30mm carb....she'll be running with the 250's!