I have two Evolution "Progressive Trainer System" engines, one .61 and one .40 that have the limiters on the high speed and low speed needles. Everyone seems to agree they should be removed. How do I go about doing this? My understanding is the blue parts are the limiters? I removed the pin on the high speed needle, but I read thats that will not work.

Thanks.

On the high speed needle, just pulling the pin is fine.

On the low speed needle, you can yank the pin out with a pair of needle nose pliers. If you don't have a screwdriver small enough to get to the low speed needle with the collar still on, you can pull the blue collar off by backing out the locking screw. You'll need an appropriately sized hex key to back it out.

Brd

Yup.

The blue low speed collar has to go too. This needle screw is more important for the reliability of throttle response and idle.

FYI: Pulling ONLY the 'pin' on the low speed won't solve your probs. Junk the collar .

If the engine is running well and you can adjust it right, there is no need to remove the collars. They don't do you any good, but they don't hurt anything either if you are able to set your needle valves right.

Some times the setting is wrong from the factory on those collars. Have an experienced pilot do the first runs and possibly RESET the collars. The collars will keep a newbie from overleaning. This makes it worth keeping them on IMHO.

Sorry but this is not enough...

The problem is that the blue collar itself is affixed via a grub screw to the needle.

As you turn the needle the limiter collar is STILL doing it's job, because the needle cannot be turned in further than the collar permits.

The grub screw on the blue collar and the collar either removed or pulled up to permit further unrestricted travel.

This is not obvious, and drove me nuts the first time I yanked the limiter pins on an Evolution engine.

I have two of these engines and haven't had to take them off of the low speed.....and actually find them easier to adjust the low end with them on. As for the high speed I usually just file down the tiny knob on the adjustment that stops the needle from turning. It only takes a few seconds and you are good to go. I've had to do this on both engines to get them to run right.

I had an Evo 36. It needed leaned out past the point the limiter would allow on the low end. As I remember I bent a tab(?)turned it past and bent them back. I left the high speed alone. It became the most reliable engine I had.-BW