ORIGINAL: jwayne
I have a super tigre 45 and having been wanting to buy a different manufacturer's carb for this engine. Please provide the details on the Perry carb. I have had 3 of the ST engines over a long period of time and have finally determined that they all are built the same and with the same problems. The money saved in buying one of these engines is quickly lost in frustration (I am a dead stick expert because of this engine). Hopefully, the other carb is at a reasonable price. After much time of tinkering with this engine by myself and a few experts, it is beginning to become a reliable engine but it still does not idle right. I now tolerate a high idle and kill the engine by squeezing the fuel line. The high idle has occasionally caused me problems getting the plane to slow down enough for a good landing....Thanks
I'm assuming the following:
- You've extensively checked for leaks and replaced the fuel tubing.
- You have your clunk 1/4" off the back of the tank or MORE
- There are no fuel flow obstructions and you've tested flow
- Your pressure nipple is clear and the tank is hooked up correctly.
- Your mid range transitions are now good as well as your high end.
Given that, I would suggest you employ the "fix" that I mentioned in a prior post above, showing the "half moon" cutout...
This is easy to do.
You've richened the low end to get a good midrange, but this over richens the low end causing the engine to bog down at times on the ground ( requiring a higher idle to keep running! ) and it will produce deadsticks in the air.
Filing out the half moon will lean the extreme low end solving the LS problem.
You need to do this...
1. Check to see exactly how many turns you have the LS needle set.
2. Remove the throttle barrel body and clean it.
3. Use a small circular file to start cutting the half moon groove.
The intent is not to have that half moon all the way down the opening. Rather file it at about a 30-45 degree angle opening up only the extreme low end.
Also don't make it too large, you want the barrel to close when the throttle is fully shut ( however note you'll have to re-adjust your end point travel to move the throttle LOWER than before ).
4. Clean and re-insert the barrel frequently to check your progress... making sure NO flakes get into the carb.
5. Re-install and start the engine. Adjust the throttle travel to achieve lower RPM's... the engine may seem to idle still faster than before at your current throttle settings ( if it does you've succeeded! ), so you'll need to set even more low end travel.
If the above fails ( it's much easier that it sounds ) you can always opt for the Perry Carb.
It is a good idea to run up the ST engines before you fly, to allow them to come up to operating temperature.
Once they are up to temp they will idle unbelievably slow for a 2 stroker.