Engine starts backwards
 

Every so often, I see or have an engine that starts backwards. You can tell, as when you rev it, the vehicle doesn't move (1-way in tranny no doubt). This happens with roto-start or drill type starters and usually only in cold weather, alhtough I admit it's a rare problem. It's not limited to the Savage, but has happened on a friend's Aftershock as well.....plus numerous other vehicles. It's certainly expected with airplane engines at times (prop flys back on compression stroke and then fires and engine keeps going in reverse), but with a roto-start system? Anybody have any insight as to why this happens?

RE: Engine starts backwards
 

I am at a loss as to how running an engine backwards is possible on a Savage, rorto start, or pull start engines. These engine have one way bearings for the pull- or roto starters to make starting them backwards impossible. That is, unless you start them with a starter box and the starter motor is turning backwards.

RE: Engine starts backwards
 

I have had this also happen on several trucks and all have roto starts. I could never figure it out either and Im an ASE certified technician.

RE: Engine starts backwards
 

I think it must be the 1-way on the backplate slipping just as the engine comes up on the compression stroke.....just as if you were starting an engine with a propellor and your finger slipped off the blade. Darned weird when it happens though. Luckily it's not very often. Always happened in winter so far, not any more since the season has warmed up......hmmm....

RE: Engine starts backwards
 

I have had this happen also and read somewhere what the most likely cause is, but for the life of me I can not recall what it was. It is indeed very strange when it does happen.

RE: Engine starts backwards
 

I think this has happened to me twice in the last week too! My one way is slipping badly, and as I was goosing up the roto on 2 occasions the engine started, and no matter how much I revved it wouldnt go or spin the wheels. Then when I started again it would run fine. Also to clarify, I tried to clean my one way with paper towel, but its still slipping. Should I use alcohol on it? Or maybe whats a good household item to degrease it, wash it in soap? Thanks.

Ah in addition, when the engine started like that, I noticed that the roto adaptor (the round thing that you put your wand in) was spinning at a slow rate at idle..

RE: Engine starts backwards
 

You can clean it with soap and water or brake clean. I get cans of brake cleaner from work and it works great. Just spray and let dry. CArb cleaner works also.

RE: Engine starts backwards
 

it happens with predetonation. which occurs more often when cold. It happened to me on my xxx-nt once, but I was actually able to run it in reverse wierdest thing i ever saw :).

RE: Engine starts backwards
 

If your using a drill, make sure it's set to reverse. Even if it is spinning forward, the one-way bearing should slip though.

RE: Engine starts backwards
 

I have seen this happen alot. It usually happens when the rotostart or drill doesn't have enough speed to turn the motor over properly. When the motor does detonate, it spins in reverse because it didn't have enough momentum in the proper direction.

RE: Engine starts backwards
 

how can an engine run in reverse? i do not understand how it can work? Would the timing not be wrong and cause the engine to not run? or is the timing just not as ideal as a properly spinning engine

RE: Engine starts backwards
 

Yes, the timing pofile would be seriously screwd up. The sleeve port and exhaust port timing profilew would be correct in relation to each other, but the crank induction port profile would be iopening and closing inclrrectly to the sleeve ports. However, the engine will still run, though like crap.

RE: Engine starts backwards
 

Yep^^ You guys just described exactly what happened to me. My one-way was slipping badly, so I had to goose the roto and the engine must have not been spinning fast enough. When it did start, it bogged like a crazy **** and wouldnt go anywhere, I knew something was wrong cause it wouldnt even move the wheels on full gas[:@]

I forgot to ask, does this screw up the engine at all? I would imagine that it wouldnt, but still curious.. Tom.

RE: Engine starts backwards
 

No, it won't hurt the engine. It might if you left it run a long time like that as the engine internal wear patterns might change. But normally you shut it off right away and there should not be cause for concern

RE: Engine starts backwards
 

Thanks for the OWB tip, I sprayed some oven cleaner in today and took the truck out, it works like a charm. Took some vids and pics:D