Help with adjustment with Symmetric shifter

[krashTest]

Hello to all. I would very much appreciate help in adjusting the shifters on my 5-speed CCM elite cruiser. I must admit I am semi-mentally challenged when adjusting the derailleurs/shifters on any bike and this one is no exception. Currently the shifter is in total disarray.

As you may notice from the photos, the shifter is a SunTour Symmetric shifter. The problem that I often experience is that the shifter will slowly begin to shift up into the highest gear when riding the bike. This doesn't happen initially but will eventually do so after a dozen rides or so.

After screwing around with the cable tension, the bike is stuck in 4th gear with the front shifter in the up position. I understand some of the basics but I just don't understand the trouble-shooting process.

I require step by step instruction. What do I do first and why? Think of this as if you were explaining how to diffuse a bomb to a child.

'Ol Dusty wants to get back on the road and would be grateful for any help. I too would also be very grateful.

Cheers,

ps- I'm aware the cable is a bit frayed and plan to replace the cable and housing and get an end cap back on.

[DaveM]

The sliding up to high gear issue should be fixed by tightening the screw on the side of the shifter a little.

For step-by-step, go here: http://bikeride.com/adjust-rear-derailleur/
Note that you can ignore all the stuff about adjusting the cable tension since you don't have indexed shifting. Basically you need to set your high and low limit screws, put it in high gear and take any slack out of the cable, done. (Assuming everything is in working order.)

[krashTest]

Sorry for my lateness but thanks for the reply. It appeared to be a combination of things, the B limit and a frayed brake cable from my guess. Once I replaced it and adjusted the screws, it came together relatively quickly. It was a real hands on process, but now shifts better than anytime I've had the bike.

I was able to get my hands on another bike that has the same type of shifting, so it was beneficial to adjust them as well.

I feel a real sense of accomplishment having adjusted them.

Cheers!