Hi all,
I've owned a Massey 65 industrial gasser with a hydraulic loader for about 3 years. My last post on here was when I bought three years ago.
I am having some misses, I think on multiple cylinders, it is especially pronounced when it is around idle and low engine speed. It will often die at idle speed, it is only very happy at 1100 rpm or higher.
I'm a newbie mechanic some I'm looking at places you would recommend checking.
1. When I got it I swapped out the points and rotor for EFI.
2. The big carb screw is not holding in place because the spring is broke. But I keep an eye on it and it stays pretty close to where it needs to. The smaller screw on the carb stays in place and I don't know if I should touch that one.
3. I replaced the spark plugs recently but did not replace the wires.
4. I used to have problems with the 12V battery being weak so I keep a battery tender on it when it is parked. The battery is new and strong but maybe the alternator isn't charging it while it is running.
5. The oil is not milky.
I'm leaning towards replacing the spark plug wires next. Anything else you guys would recommend to check out?
That's a nice engine. A low speed miss may not be easy to find - especially for a newbe, but it also means that there probably isn't anything really wrong with the engine. Chances are good we can find it and it will be easy.
You are right to start with a general tune-up.
BTW, I think that you meant to type EI for electronic ignition. EFI is electonic fuel injection which is a whole different and much more complex change.
Frankly, I would have stayed with the old points and rotor. The old system is an easier system to check out, cheaper parts, and nearly bulletproof.. But the EI wasn't a bad idea, just apparently not needed. We can work with what you have; the basics are the same. So time to begin. With gassers we always start by making sure that the spark is good, then we go to the carb only if needed.
You need good spark at the plugs, so begin at the plugs themselves. If not new, then take them all out, clean them good inside and out and make sure the connection to the spark plug wires is good. Check that the spark plug wires are in fact rubber insulation covering a metal wire right up to the spark plug cap. There was a time when it was popular to use carbon filament instead of wire and those spark plug wires didn't last - they often broke internally. Anyway, you can check the plugs by laying the clean plugs all in a row making good connection to some metal part of the engine and then cranking the motor while you look at the spark in each plug. Do it in the shade and look at the spark you are getting at the tip of the plug. All the sparks should be roughly the same: fat, blue and bright and audibly snappy. A weak spark is yellow and feeble. If some are not, check that the spark plug is laying with the body of the plug good connection to the engine block, and that you aren't loosing spark there. That is because the spark wire is only half of the circuit to the spark plug. The other half of the circuit travels through the metal of the spark plug body and then to the metal of the engine and back to the spark coil. You need a good complete circuit, so the body of the spark plug needs good contact with the motor block for this test to be right. You can even rig up a lightweight jumper cable to insure the plug is properly grounded to the metal of the tractor motor or even hold the BODY of the plug against the motor block with your fingers (just don't touch the tip of the plug!!) But spend the time to do it right. Troubleshooting, is like a detective story; each step depends on the step before.
If you did not get good spark and you've made sure the connection of the spark plug body to engine block is good, then suspect the spark plug itself. Get a brand new spare plug to use as a test plug, one is enough. Try the test again using this known good plug. If the spark is still weak or still no luck, suspect the spark plug lead. You can swap leads with another plug _ BUT KEEP NOTES or MARK ON THE DISTRIBUTOR CAP TO MAKE SURE YOU RETAIN THE PROPER FIRING ORDER. The proper firing order WILL NOT BE 1,2,3,4 , it will probably something like 1,3,4,2.
If the spark is still not good, then it may be the distributor cap itself. They do eventually break down and short out inside, but it is rare. Usually a cap is good for several sets of wires. With the plugs out like this, you can swap leads around until you find which plug is not not sparking well and fix it. If none of them spark right then the problem is the distributor cap or 12 volt spark coil. Swap things until you know which.... These are inexpensive. You need a continental distributor cap, but most any spark coil will work including an old chevy or ford type.
Anytime in this process when we get a good spark to all the plugs there is nothing wrong with putting the plugs back in the engine and firing it up to see if it still misses. If it doesn't miss then we are done. If it does, then continue as below.
And if the spark is still weak we would normally go next to the points and rotor....but we will instead just have to trust the EI system because we can't really check it. I'm betting that by now the spark is good at all the plugs so put them back in the motor and see if it still misses.
If so, then you might check the timing...but poor timing is normally a high speed miss, not a low speed miss. Timing is quick and easy, but it is also best the first time to get a buddy with a timing light to help with that. It will only take half an hour and the timing will be good for the life of the engine.
If you think the timing is good - and I would think it should be - then it is time to go to the fuel system.
Later...fuel feed....
If the spark is good everywhere and it still misses, we go to the fuel system. But not to the carb yet. We check that what is in the tank is actually good fuel without water. Usually that means draining the tank and cleaning the inside with a sock on a stick. Next check the fuel feed line, any fuel filter, and the on/off fuel tap, and any fuel pump if it has one. The object is to make sure that full fuel flow is available to the carburetor.
We can do the carb too, but it is more complicated. Hopefully by now we've found the miss.
Oh, on the carb, I would leave it as is for now. Whatever you do, do NOT screw up and lose the number of turns on those screws. If you do, we can recover....but it's a hassle.
Just so you know, "Turns" on the adjusting screw are figured by the number of full turns plus a fraction as rotated OUT from fully bottomed or clockwise position. If checking the turn number, do not force the screws, they may have soft brass faces. "Bottomed out" means turned all the way in (clockwise) with medium finger force.
I'd leave the screws as they are for now. We don't need anything else to add to the mystery. Eventually You can get a spring at any Ace hardware store but may have to cut the spring to length. For now, just leave it.
Luck,
rScotty
