View Single Post
  #1  
Old 12-09-2016, 01:20 PM
toomanytoys2's Avatar
toomanytoys2 toomanytoys2 is offline
Contributor
 

Join Date: Sep 2012
Location: Lefty California
Posts: 284
Default Warning-Warning-Warning about Shock Length

I have never heard of this happening, but it did to me. I have a hammerhead twister 150 and I installed Blaster front shocks on the rear of the buggy. This did a MAJOR improvement in ride quality. The shocks have been on there for a couple of years. I don't just blast around fields, but I take it to the desert and put some serious miles on it. Last time out we decided to go for an ice cream run. Where we camped is called Searles Station. It is in CA off of 395. About 20 miles away is a tiny town called Randsburg, and they have an old fashion ice cream fountain, and you can drive your off road vehicles through town.

About half way there, the buggy seemed to ride like #@$%, and it was killing my back. I also thought that I was getting a whiff of fuel. Once we hit town I discovered a major problem. The engine's head had punched a hole in the fuel tank. The problem happens when you put longer shocks on a particular style of rear suspension. The first picture is the type I am describing, and the problem is with the silver link arm.

In a properly working suspension, when it hits a bump and compresses the link arm moves in the direction of the arrow in the second picture. However, when you install longer shocks, the link arm goes from a slanting forward position to a vertical position. Then if you unload the suspension (catch air) and the frame flexes, the link arm will go past center, and travel in the opposite direction like in the third picture. When this happens the engine will flip. So the cylinder and head will go from a horizontal position to a vertical position, and crash into the bottom of the fuel tank. In my case the head punched a hole in the bottom of the fuel tank.

I'm pretty sure I know when it happened. There was a pretty mean ditch that I had to cross, and the exit wasn't very pretty. Once we got to Randsburg and stopped, the fuel smell was over powering. So I got out of the buggy and looked and there was the engine's head hitting the fuel tank, with fuel running out. Luckily, one of the families with us had driven by truck, so I bummed a ride back to camp, picked up my trailer and brought the buggy back to camp.

I then drove into Ridgecrest and got a fuel tank repair kit from a FLAPS and was able to patch the tank. To get the suspension back into its correct position, I jacked the back of the buggy up and we kicked the suspension links until they returned to the original positions. I then used a rope to make a limiting strap to control how much the rear suspension would droop. Now I have to figure out how to make a more permanent limiting solution.

I have never heard of this happening, but I just wanted to put the word out there, so someone else doesn't get their ride ruined.
Attached Images
File Type: jpg Link angle.jpg (92.7 KB, 44 views)
File Type: jpg Link angle proper travel.jpg (93.2 KB, 40 views)
File Type: jpg Link angle improper travel.jpg (93.1 KB, 41 views)
__________________
2005 Hammerhead 150
170cc BBK, PnP Big valve Head, A12 Cam, Uni Filter, Custom Exhaust, 10G rollers, 1500 Contra Spring, 2000 Clutch Springs

Just added - 2007 Joyner 250 SV - Let the fun begin

4-Dirt Bikes, Baja Bug and enough toys to keep me in the garage and out of trouble.
Reply With Quote