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Subject: 860

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Jack - Iowa    Posted 10-15-2019 at 15:19:21 [URL] [DELETE]        [Reply] [Email]  
  • 860
  • Just finished installing a gasket between the transmission and center housing. Now she will not start!

    Has hot spark out of the coil but nothing to any plug. Points, condensor, Rotor, Cap and wires all new in August 2018. Even went to town and got a new rotor and cap with no change! If I manually rotate it to where the rotor is right for a particular plug, place an insulator in the points and use an external wire to trigger it I get a nice spark from that plug. What am I missing?

    Jack

    JMOR    Posted 10-15-2019 at 15:43:10 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • I would bump it around until I see the points just starting to open and at that poing examine relationship of rotor to a distributor cap plug tower. No other work on distributor than changing the items you mentioned?

    Jack - Iowa    Posted 10-15-2019 at 15:52:24 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • At this point I have reset/checked that twice.

    Found some play in the cam but eventually determined the that was normal.

    JMOR    Posted 10-15-2019 at 16:05:59 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • IF the rotor is aligned with a tower as points just begin to open and coil spark does not make it to tower, then it must be finding another path to ground, such as rotor to shaft. If not aligned, and no insulation breakdown, then it can't make the large jump caused by mis-alignment. Are you cranking the engine while observing "good spark out of coil?", or simulating points closing/opening with wire, screw driver, etc.?

    Jack - Iowa    Posted 10-15-2019 at 16:19:47 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Cranking the engine. It is a puzzler!

    JMOR    Posted 10-15-2019 at 16:22:55 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • Have you looked at the mechanical advance mechanism?

    Jack - Iowa    Posted 10-15-2019 at 16:37:50 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Looked at the weights. Appear to be alright to me but I'm not really familiar with them.

    JMOR    Posted 10-15-2019 at 17:05:45 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • The weights are returned with springs and have posts which fit into slots on plate attached to shaft & as they travel the slots, with increasing rpm, that rotates the point cam relative to the shaft & rotor. If anything there were amiss, then it could cause points to open when rotor is out of alignment with cap tower. You have indicated that rotor is in alignment with tower when points begin opening, so perhaps there is nothing to worry about here.

    Jack - Iowa    Posted 10-16-2019 at 08:50:06 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Decided this morning to recheck my work from yesterday.

    Rotated the engine around to 4BTC. Pulled distributor cap. Rotor is over 90 degrees clockwise from where I set it yesterday! Would you agree I have a bad timing gear?

    rgeiger    Posted 10-16-2019 at 12:12:44 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • Not sure about the 860, but the 8nside mounts have two sets of timing marks on the flywheel.

    Jack - Iowa    Posted 10-16-2019 at 15:12:46 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • I also learned something.

    Thanks for posting. This is becoming a real puzzler.

    Jack

    JMOR    Posted 10-16-2019 at 13:22:50 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • flywheel on Ns will bolt on in either of two positions, whereas hundred series will bolt on in only one position, so no need for dual set of marks.

    R Geiger    Posted 10-16-2019 at 14:14:19 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • Learn something every day, thanks!

    JMOR    Posted 10-16-2019 at 10:02:41 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • If all your work is good, it sounds like I agree, however, the pin in gear could be sheared or the weld holding advance plate to shaft could have failed? If you aren't ready to pull distributor to investigate, I might see if the same 90 position repeats of if it changes with each attempt. If something in gear, pin, plate is amiss, I would expect it to keep changing.

    Jack - Iowa    Posted 10-16-2019 at 15:06:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Did pull the distributor and checked. Looks good. Had a question which you answered in your answer to Bob.I am finding #1 compression occurs before the timing marks are in the window. Is it possible the engine was assembled so the timing marks mean nothing?..

    JMOR    Posted 10-16-2019 at 15:43:22 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • Compression isn't instantaneous, as it begins to build as the piston starts travel up the bore and continues to build as it compresses the cylinder volume, pretty much for the 100-180 degrees of crankshaft rotation, and peaks as it reaches TDC-compression. As for assembled wrong.....well, it has been running fine and hasn't been re-assembled, has it?

    Jack - Iowa    Posted 10-16-2019 at 16:45:14 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • I guess my real question is could a previous owner have botched up so I must find some non-normal configuration?

    JMOR    Posted 10-16-2019 at 17:15:52 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 860
  • Highly unlikely that crank to cam gears could be out of time, especially since it ran fine not so long ago. As to distributor to cam, oyu re-install that correctly and it should be good. It should have been good (it was running) before, unless the pin sheared or something broke as we have discussed. The trouble is likely more simple that deep. Do you still have distributor out?

    Jack - Iowa    Posted 10-16-2019 at 18:05:28 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • No the dist is reinstalled with new points and condenser. Had a fellow come and look at it. He says cap or rotor but I already tried new ones. I'll be pulling the rotary mower tomorrow with the 2N. The 860 willset.

    Jack - Iowa    Posted 10-16-2019 at 15:05:36 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Did pull the distributor and checked. Looks good. Had a question which you answered in your answer to Bob.I am finding #1 compression occurs before the timing marks are in the window. Is it possible the engine was assembled so the timing marks mean nothing?..

    Jack - Iowa    Posted 10-15-2019 at 17:12:14 [URL] [DELETE]        [Reply] [Email]  
  • Re: 860
  • Yes I saw the springs and posts. All looked fine but nothing was shiney.I also saw the cam has a little rotational looseness in the advance plate. That is what sent me on one wild chase.

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