1976 cyclone 440 pto cyl issue

[jayson738]

If I could I would like to pick your brain on this issue I am having with my 1976 john Deere cyclone. The engine has been resealed and re-ringed by myself and I work on marine engines for a living so I know it was done correctly. I was going to gamble with the original prestolite ignition components after the overhaul. I did this about 4 years ago. Also coils were replaced at this time. The sled is being built with the intentions of doing vintage ovals. I was going to try to run the sled with the surface gap plugs that john Deere recommends for sustained high speed operation just so I did not do any damage to the engine while breaking it back in. The engine however was not making enough spark with those plugs to run, so I installed BR10es plugs then the engine would run but was lacking power and would not get out of its own way. I tested the stator and got not so good readings, So I sent my stator into hewtech to get it exchanged with a rewound one. I pulled the engine put the stator in and set the engine back in the sled. Fast forward to this winter. I did not mess with the sled for two years after getting the stator due to time restraints. I hooked the engine up and finally got it running with the rewound stator. It fires up good I could get the sled to move better than before however I was only getting the rpms up to about 5500 max on low snow long run the clutches seem to be shifting correctly and have been serviced. At low rpms the engine loads up and smokes a lot spews oily fuel from exhaust joint and exhaust exit. I found that the pto cylinder plug is very wet with fuel and firing correctly. So ok I did a spark check with an adjustable spark tester set it to 3/8” gap and it jumps it on both sides. Ok still could be a coil issue so I swapped the leads both coming from the cdi and then crossed them to the opposite cylinders ran it and the problem stayed on the pto side so the coils are good. Well so The only thing it could be is the cdi isn’t firing correctly to the pto right?? So I ordered the cdi box from hewtech thinking it should take care of the issue. This is a single carb engine so I don’t think it is an over fueling issue factory jets and settings. I double checked the compression and have 155psi per cyl. I have also used a cylinder dial indicator to check that the crankshaft is not twisted and from the testing I have done it appears to be dead nuts on. Could the trigger be causing this? That is the only thing in the ignition system that I have not replaced yet. Could a bad tachometer cause this? I have not tried to disconnect the tach. Any insight if you have any to help me get this thing running right would be appreciated.

[harleysportster]

If I could I would like to pick your brain on this issue I am having with my 1976 john Deere cyclone. The engine has been resealed and re-ringed by myself and I work on marine engines for a living so I know it was done correctly. I was going to gamble with the original prestolite ignition components after the overhaul. I did this about 4 years ago. Also coils were replaced at this time. The sled is being built with the intentions of doing vintage ovals. I was going to try to run the sled with the surface gap plugs that john Deere recommends for sustained high speed operation just so I did not do any damage to the engine while breaking it back in. The engine however was not making enough spark with those plugs to run, so I installed BR10es plugs then the engine would run but was lacking power and would not get out of its own way. I tested the stator and got not so good readings, So I sent my stator into hewtech to get it exchanged with a rewound one. I pulled the engine put the stator in and set the engine back in the sled. Fast forward to this winter. I did not mess with the sled for two years after getting the stator due to time restraints. I hooked the engine up and finally got it running with the rewound stator. It fires up good I could get the sled to move better than before however I was only getting the rpms up to about 5500 max on low snow long run the clutches seem to be shifting correctly and have been serviced. At low rpms the engine loads up and smokes a lot spews oily fuel from exhaust joint and exhaust exit. I found that the pto cylinder plug is very wet with fuel and firing correctly. So ok I did a spark check with an adjustable spark tester set it to 3/8” gap and it jumps it on both sides. Ok still could be a coil issue so I swapped the leads both coming from the cdi and then crossed them to the opposite cylinders ran it and the problem stayed on the pto side so the coils are good. Well so The only thing it could be is the cdi isn’t firing correctly to the pto right?? So I ordered the cdi box from hewtech thinking it should take care of the issue. This is a single carb engine so I don’t think it is an over fueling issue factory jets and settings. I double checked the compression and have 155psi per cyl. I have also used a cylinder dial indicator to check that the crankshaft is not twisted and from the testing I have done it appears to be dead nuts on. Could the trigger be causing this? That is the only thing in the ignition system that I have not replaced yet. Could a bad tachometer cause this? I have not tried to disconnect the tach. Any insight if you have any to help me get this thing running right would be appreciated.

Did you have the center seals replaced ? You can check those by pressure testing the cylinders, one at a time.





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[farleyjd400]

Pressure test the engine first to eliminate any leaks from the seals.

[jayson738]

I have not that was my next step. Have to make some block off plates. The seals looked ok from what I could see of them when I had the crank out however that is what I am suspecting. I have another crankshaft that I can send out and get them done on just in case that is the issue.

[jep_800]

You did not mention timing the engine, but with all your other work, perhaps that's already been done per the manual?