Is it running too hot?
I havnt got a temp gun but I shall order one. If its too hot would that e the cause? Also would that mean uts running too lean?
I am not a nitro guru, but if it runs good when you first start it then runs bad after it is ran for a bit, that would be my guess. In any engine, running lean will cause it to run hotter, causing the tune to be off because of the change in temp.
Boy, I learned a lot. Thanks!Very hard to diagnose the problem ,could be as simple as your idle is a tad too low ,for the ratio
of the Lsn needle is set at ,after a run an you bring in an your idle drops ,then drops again even
lower ,then that is called a two stage idle!
A two stage idle can happen 2 ways ,one way is a false reading because your model may not
have a throttle return spring that keeps constant tension on the throttle rod in the closed
position an causing a false idle setting tune ,if you tune the engine with out it ,you can be tuning
with the throttle slightly opened up than normal ,so make sure that you have some kind of return
spring that puts a little tension on the throttle rod linkage!
Second ,your Lsn tune is not properly set or in sync with your idle gap ,at this point ,you are not
far off of the tune ,you are just having a flame out ,so your LSN could be either too lean or could
be too rich ,how to determine which!
If your engine puts out heavy smoke an is sluggish on take off ,then it is too rich ,lean the Lsn
needle in a little ,dont turn needle too much ,only a 1/16 of a turn at a time an make another
pass an check to see if it cured the problem ,the RPM's may raise slightly if it does ,lower your
idle setting!
If its too lean for idle your ,you wont have harley no smoke or residue coming out of the exhaust .
simply richen up the Lsn. until you have a good take off with some smoke ,but may have to bump up
the idle set screw to raise the idle up or match the air ratio with more fuel coming in for a good idle!
So ,you have to determine what the engine is doing ,is it flooding out & choking itself out or is it
starving of fuel?
If it is flooding a little too much ,sometimes all you need is to bump the idle up a little ,it is not
really good to have the idle set as low as it can ,because the engine can load up with fuel if
it sits too long at idle an flames out when you pull the trigger to take off ,that is also a good indication
that the Lsn is a little too rich!..
The linkage from the servo will have enough play in it to cause your tune to be all over the place like baker said. You definitely need a spring on there.
