My blue stripe 918's are reaching 15K miles with a TR224 cam. I wanted to check the spring pressure to see if I'm within spec, so I won't have to spend cash on new springs if I don't need them just yet. Anyone know where to get a good tool to check spring pressure? Did a search on this subject and went through all 10 pages, but none mentioned a tool...

 

WalMart, or Shopko, LOL! All you need is a bathroom scale and a common drill press. Put an old intake or exhaust valve in the chuck to push on the spring. A cheap Harbor Frieght dial indicator will measure height. You might want a strong metal plate on top of the scale so you dont dent it in with the spring.

I'm sure your springs are OK. I just removed my 918's and TR224, and they all tested like new; 15K miles. I race every other weekend, and drive like an animal on ther street.

 

You're kidding about the bathroom scale, right? So I should be able to get one from harbor freight? It's not that I don't believe your springs were great after 15K miles, but I've just read a few posts of the 918's and wanted to check them before I decided to leave them on another 5-10K miles.

 

Nope, I'm not kidding. I use a nice digital bathroom scale that's accurate to 1/2 lb, but that's overkill. Harbor Freight is just for the dial indicator, but that's overkill too. You could just use a ruler or make a couple of spacers, one for the seat height and one for full open height.

 

I called a local reputable machine shop. They checked mine for free, I just gave them the specs. I think it was 130 lbs at installed height of 1.8.

 

Comp 918
Installed Pressure: 130 lbs @ 1.800"
Open Pressure: 318 lbs @ 1.200''
Coil Bind: 1.085"
Maximum Lift: 0.625"
Rate (lbs/in): 313 lbs/in

 

Summit sells the Proform spring checker, but it's around $220. I don't think I've ever seen one cheaper than that one.

 

Here's 1 from Summit. You just need a vice.

http://www.summitracing.com/catalogs...nfeb/154f.html