I am familiar with the engine as I have one in my shop that has since been converted to a 1915. Backfiring can be caused by running too lean, and probably by a timing that is too advanced. Your engine should run at the same, or nearly the same RPM, with either ignition, on and the other off. If it doesn't, one or both of them is not at the correct advance.
My current engine is a 2276, that started life as a GPASC 2180 that I was running at 28 advance. I first set my mag, and if you don't know how to do that, get one of your friends who has a mag driven ignition and get them to help you. I found an A&P who is a member of our chapter and got him to check behind me to make sure that I had it right. Make sure that the engine runs properly on the mag only. Then set the electronic, and do the one on, one off test. You will only be able to record the RPM on one of the ignitions, so you will have to listen carefully for any difference when you turn that one off. On mine it records on the MAG and not on the electronic. If the engine dies when you turn one of them off, don't panic until you check to be sure that you remembered to turn the other one back on. When I went to the 2276, I had to drop the timing advance from 28 to 25 due to overheating problems, which are to be expected. When I did that, I got the un-expected benefit of a lower and more smooth idle. Mine will idle between 650 and 700. I think that anything 650 to 800 is good, don't try to get it below 650. AND, if you want to taxi without the wings on, stay off the runway. I won't tell you how I know, but I am sure you can guess. See N64KR at http://KRBuilder.org - Then click on the pics See you at the 2010 - KR Gathering in Richmond, Ky - I39 There is a time for building and a time for FLYING and the time for Flying has begun. Daniel R. Heath - Lexington, SC -----Original Message----- Now back to my original question about the backfiring/timing problem. Can anyone help with that? That's what I really need to have some information on. I'm sure others have encountered the same problem. C'mon guys, chip in here if you will, I need some advice.
