Help !! Spun new engine backwards
10-27-2007, 12:56 PM
#1
Help !! Spun new engine backwards
I have a Jammin .12 that I am breaking in. Got a new starter box for CRT .5. Trying and trying to fire motor and would not start. Finally figured out that the leads on the starter motor were backwards and I was spinning the motor the wrong way. Since I have fired and started to break in motor. The motor seems to run fine. Did I do any damage that I don't know about yet? Thanks
10-27-2007, 01:00 PM
#2
I did this recently also. It was weird that the tires were spinning backwards. Since you're breaking it in, just don't do it again. Run it. It'll be fine. But if this is your first engine it will be a crash course anyways. Like what just happened to you. LOL. Naw, don't worry. Just remember for next time.
10-27-2007, 01:44 PM
#3
This is my 7th offroad gas vehicle. Never had done this before. I figured it out because the wheels were going backwards. Crazy!!!
10-28-2007, 04:28 AM
#4
Nah.. don't worry, it won't harm your engine.
10-28-2007, 04:31 AM
#5
if u use a pull start, sometimes on the re-coil the fylwheel may spin backwards, if at that moment it fires up then the car will run backwards.
10-28-2007, 05:03 AM
#6
This happens all the time with air plane engines when you "flip the prop"to start. Absolutely not a problem 
10-28-2007, 07:13 AM
#7
Any two stroke will run backwards
I found that if you hold down the flywheel on the starter wheel instead of bumping it they will start backwards more often. If they are doing it frequently its usually in need of some adjustment to the timing. If your motor fires way early on that first pop it doesn't have enough momentum to carry it past TDC when the explosion happens. It takes the path of least resistance and goes the other way and by the time it gets to the top again it has momentum so it continues to run backwards. The plug doesn't know which way its turning and works either way. I had a Nova 35+21 that was heavily modified in my top fuel car and that thing was a bear about starting backwards. On the timing thing its usually too advanced when it starts backwards frequently. Add a little shim go to a colder plug or reduce the nitro % to retard the timing a bit. I had a 2 stroke motorcycle when I was a kid. If you let that motor lug and almost die it would start running backwards. First time it happened I thought I was in a time warp or something. My brother had the same bike and his didn't do that. We never could figure out why that one bike did it and the other did not.
Griz
Griz
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