IDC stands for Inertia Dynamics Corporation,take the muffler off and then try to see if it will run a top speed don't do it for very long time,the muffler on these trimmers are bad about clogging up,I always soak them in carb cleaner,and rinse them in water and heat them with a small propane torch.This trimmer sounds like it has a clutch,so when you speed it up the head will turn,it not suppose to turn at idle.Hope this helps

Jerry

Did you get the correct mixture recipe for a 15 yr. old machine? Might not have enough oil in the mixture. The older machines had different tolerances for how much or how little gas to use in the mix!
Back in the olden days, a half pint of oil to a gallon of gas was the norm! Things have changed, but you might try a bit more oil in the mix!

What happened?

This is probably way too late to be of any use to you but the correct mix for this trimmer is 32:1.

hello i am looking for the string spool for my IDC 500s trimmer s/n 903075645. This is a great trimmer and just need the complete spool...

This machine, The Ryan - IDC trimmers, are an easy fix, My dad, Rodger Coziahr ran a refurbishing facility for just this item. It is an easy fix and he points above are both useful and correct. As a point of history, his facility trained warranty mechanics by the dozens as a reverse logistics and refurbishing strategy to minimize returns from retailer such as K-mart, Walmart, Lowes, Ace Hardware and Home Depot. Not a bad product at all, he just sold a TON of them and so it got it fair share of people who simply did not know who to prime the pump and so returned it to the store.

looking fpr parts for a ryan 284 trimmer. ùneed the plastic cap and choke switch on the engine. ùcan anyone help or suggest where i can get one

Try a guy called Randy's Engine Repair on Ebay. He's in Podunk, Ohio. Prices are high, but if he doesn't have it, no one does.

When they are that old parts are impossible. And they will nickle and dime you till death. I have an old 990r runs great, but I cannot get parts for it.

Good luck!