" Hi,
This engine has a mo
" Hi,
This engine has a model # of 85790S and a serial # J001073. I got it in an unkown state and found that it had compression, but was lacking spark on two cylinders, here's how it went.
First, I verified that there was still no spark on the port side and that there was spark on the starboard side, using a spark tester. Switch lead (from power pack) to coil for starboard side w/ lead from port side (1&2 and then 3&4); found that the lack of spark switch sides as well. Put it back together in original way. Next, switched "sensor" leads from port side to starboard side (1&2 and then 2&4), found that once again, lack of spark switched sides.
At this point, I decided that it must be the sensor coil and checked resitance between sensor leads for coil 1 & 3 and then 2 & 4. Resistance was 7.8 for bothe; this appears to be in spec. . Last, tested for resistance between ground and those leads, found it to be infinity (no continuity), which was also to spec.
I put everything back together again and then did a spark test on the each cylinder and found that all but one cylinder, on the port side, were now firing. The cylinder that was not firing would fire for a couple beats and then quit. I double checked that by switching the sensor, this condition would change, and it did, and then tested it all again and found all cylinders had stopped firing. I checked the ignition switch lead (on the power pack), there was no continuity to ground. I disconnected the ignition switch lead to be sure, without change.
I don't know if this means anything, but even when the engine is not being turned over, I've been getting lots of shocks out of the power pack and leads around it. I'm thinking it's just the stored voltage?
Should I still assume that it's a sensor coil? Does it sound like possibly something else? How might I trouble-shoot this now? Any/all help appreciated,
Jon "
This engine has a mo
" Hi,
This engine has a model # of 85790S and a serial # J001073. I got it in an unkown state and found that it had compression, but was lacking spark on two cylinders, here's how it went.
First, I verified that there was still no spark on the port side and that there was spark on the starboard side, using a spark tester. Switch lead (from power pack) to coil for starboard side w/ lead from port side (1&2 and then 3&4); found that the lack of spark switch sides as well. Put it back together in original way. Next, switched "sensor" leads from port side to starboard side (1&2 and then 2&4), found that once again, lack of spark switched sides.
At this point, I decided that it must be the sensor coil and checked resitance between sensor leads for coil 1 & 3 and then 2 & 4. Resistance was 7.8 for bothe; this appears to be in spec. . Last, tested for resistance between ground and those leads, found it to be infinity (no continuity), which was also to spec.
I put everything back together again and then did a spark test on the each cylinder and found that all but one cylinder, on the port side, were now firing. The cylinder that was not firing would fire for a couple beats and then quit. I double checked that by switching the sensor, this condition would change, and it did, and then tested it all again and found all cylinders had stopped firing. I checked the ignition switch lead (on the power pack), there was no continuity to ground. I disconnected the ignition switch lead to be sure, without change.
I don't know if this means anything, but even when the engine is not being turned over, I've been getting lots of shocks out of the power pack and leads around it. I'm thinking it's just the stored voltage?
Should I still assume that it's a sensor coil? Does it sound like possibly something else? How might I trouble-shoot this now? Any/all help appreciated,
Jon "