perfect timing?????????

[george3405]

My 1989 Evinrude 48 spl is still not running. I need a way to check/ set the ignition timing without the engine running. Anybody know how to do that. The manual I have does not say anything on that.

One other question. I'm rebuilding the carburetors. The dropped float level, according to my manual, is supposed to be 1 1/8" to 1 5/8" from the casting to the bottom of the float. It was about 1/2 of that measurement. Would this short (maybe 3/4") float level cause the engine not to start and to backfire. I have strong blue dspark at the plugs and timing seems to be right,but I need to check it.

Thanks for the help!
George3405

 

[jeffl78]

Re: perfect timing?????????

As for your timming issue that motor should have a ecu (brain, or spark box) that controls most of the ignition events. I would think that there is no adjustment that can be performed. Does this motor have anything more to the ignition then a pulse pack, magnito, and coil packs? Does it have a distributor cap just to controll the firing order? Whats kind of general layout does the ignition have? I don't think I've ever been around a motor like yours. Is this motor capable of triggering an engine warning light? Is it on?

My guess for your second question my answer is yes for the most part. I say this because I have heard plenty of two strokes backfire when the carbs were not set correctly. However, usually, this is caused when the carb is letting in to much fuel in (flooding the cyliners). I have also heared an outboard backfire when the ignition timming was off to.

 

[george3405]

Re: perfect timing?????????

The engine has a power pack/ ignition module, and coil; no distributo. It does have a flywheel with timing marks on it with 19 degrees highlighted.
Thanks,
George3405

 

[F_R]

Re: perfect timing?????????

Hands off! Unless you have already messed with the timing, leave it alone. You need a timing light and test prop to set it, and the motor has to be running.

Anyhoo, the timing adjustment is for maximum spark advance and does not have a thing to do with starting because you start the motor at less than full spark advance. Yes, it probably would kick and buck if you were to try to start it at full advance for some reason.

As for the float level drop, I doubt that has anything to do with your starting problem either. If they drop at all, it will admit enough fuel to the float bowl to at least get it started. Could affect continued running after starting though.

Have you had any wires loose from the power pack? Now that could cause backfiring when starting if it is wired wrong.

 

[tashasdaddy]

Re: perfect timing?????????

are the spark plug wires in the correct postion?

 

[clint]

Perfect timing?????????

Perfect timing?????????

I agree the wiring has to be wrong? Good Luck!
Clint

 

[george3405]

Re: perfect timing?????????

I did change the power pack/ignition module unit, the coil pack, the plug wires, the plugs, rebuilt the carbs, changed out the fuel/cleaned the tank, and added a fuel seperator filter. I did find a wire that runs from the power pack to another coil (magneto, under the flywheel) that had the insulation nicked through. I taped it up and the backfiring deminished except for once in awhile. I checked the wiring several times and everything appears correct. This engine is only a 2 cylinder and I switched the plug wires but the backfiring got worse. I have good blue spark at the plugs, but I'm not sure I'm getting fuel from the carbs to the cylinders. I cleaned and rebuilt both carbs and fuel is getting from the tank to the carbs????????????
George3405

 

[Joe Reeves]

Re: perfect timing?????????

(Carburetor Float Setting)
(J. Reeves)

Don't be too concerned with the float drop. Just don't let it drop too far as that could possibly (but not probable) disengage the float needle valve.

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

If anyone has had the flywheel off and not torqued the nut down properly when reinstalling, that will cause a shearing of the flywheel key. This throws the engine out of time and normally it will not start at all, BUT if the key is only sheared slightly by a few thousands, the engine might run erratically, backfiring etc. That nut must be torqued to 105 foot pounds.

Wires from powerpact to external coils..... Orange/Blue to top coil. Plain orange to bottom coil.

Wiring..... worn insulation, frayed wiring, any faulty wiring... repair or replace it properly. Patch work is not acceptable.

If you're referring to a loud type backfire, the type that sounds like a shotgun firing out of the exhaust, the above pertains.

If on the other hand, you're speaking of a mild carburetor spitting back type backfire, more of a cough than anything.... the carburetor(s) are opening too soon OR a carburetor problem (clogged jets) exists.

 

[george3405]

Re: perfect timing?????????

The backfire was a loud gun shot sound from the exhaust. I taped up the insulation on that wire with electrical tape. Only way to fix the problem totally is to replace the coil (I think it is the magneto, but not sure). The spark plugs do not seem to get flooded with gas no matter what I do and I know gas is getting to the carbs. Anything between the carbs out side and cylinders that could be stopped up or seized not letting gas to the cylinders?
Thanks,
George3405