Hey guys, just got back to the states (Nebraska!!) a bit ago from indonesia where I live and ended up taking on a project for a family friend. Was going to be fun I thought haha, still is, just chasing gremlins like crazy and now hit another one that I haven't been able to figure out and I've been researching the crap out of this thing and watching videos cause they are really cool engines even before I found out how really cool they are (I like all old engines and working on them). I got a bit of some autistic traits so sorry about what you guys are about to read because I'm very curious and detail oriented and that's why I love engines... but also have to solve them or it drives me crazy haha. So I'm sorry about the long post.
So anyways, it's a 78' 900 (90hp 2-stroke: serial #4846442) with an ignition switch box, single coil, and distributor. It had sat for ages in this places front yard by the state lakes, I remember it from when I was young and still living back on the farm. So as you can guess the wiring harness is trash, which over in indonesia I normally make my own but this guy has agreed to buy a new internal and to remote throttle harness but I'm trying to diagnosis it to see if I need to order anything else cause my time is limited in the states. So while trying to diagnose the spark issue i've had it running that many times, come out the next morning and it's no spark. So I'd tweak some things and it'd run again, but this last time I'm not sure what happened but it's weird. I've checked grounds between all straps, cleaned/sanded all the switchbox/coil/distributor terminals, wrapped and cleaned all the wire connections and it was running fine but I didn't want to push it since I didn't know when the last time the water pump was changed but it ran good (minus carb leaks but not a problem for the spark issue). The last time I didn't have spark, and this is where it gets weird, is that I read that grounding is a big issue and I added a alligator clip from the switch box (lower screw hole on the body) directly to the internal wire harness ground on the side cowling. I turned it over and it started on 5 cylinders (#1 shocked the hell out of me even though I was holding the boot and ground the plug to the frame bolt). So I installed the #1 spark plug and tried to start it again and the starter sounded like it was taking a huge load and going slow but then it kicked off and ran fine and I shut it down. But my alligator clip connection got super hot and after trying to start it again it actually popped???? I did a quick check test on the switch box and coil and had spark (standard red and white terminals had 12.4v, detach distributor leads and coil high tension wire, bridged the lower two distributor side terminals and grounded the top and got spark from the coil high tension wire against the block) so think the switch box and coil are good but didn't have time to try the distributor trigger cause I thought it need to be pulled but have since found out otherwise cause you can just turn the engine by hand. I'm heading back to the farm tomorrow so will do that test but still got no idea why that ground popped and I lost spark.
So that's where I'm at now so I'm trying to figure out at much as possible before getting my hands back on it. I've read so much up on this but some info is conflicting so that's why I'm posting... my long post haha. In video's I've watched and articles I've read, it appears that if you do the switch box/coil/trigger test it will just run! Other's say that a failed stator or rectifier can also kill the spark. I've already disconnected the mercury tilt switch to rule that out even though when it was hooked up it was still running. I found one article saying there is a "momentary" kill switch on the push/pull shift linkage (makes it easier to shift into gears) that can cause failure but I haven't been able to check since leaving the farm so not sure. Other say starter solenoid as well....
So I guess what I'm asking, does anyone know a complete list on what to check or rule out if not connected to spark issue? What I know or have read so far in my 50+ hours of research is below but need help confirming:
-12v or so to the red and white connections on the ignition switch box
-do a coil test by the above mentioned (remove distributor cables, bridge two lower on switch box, ground top, remove coil high tension and spark to block)
-rotor cap or spring and carbon brush (trigger test, which i haven't done yet)
-mercury tilt switch
-bad stator??
-bad rectifier??
-bad starter solenoid??
-"momentary" kill switch on push/pull shifting cable??
-grounds
-does it have a different kill circuit even if I have 12v at the red and white?
-others?
And also, say with my ignition switch box and coil test where I did get spark, do the ever intermediately go out or are they either good or bad? Same for when I check the trigger tomorrow?
I need a beer guys and I'm sure you're already thinking wtf after reading all this, it just keeps me up not knowing the answers. But again, if I disconnect everything from the switch box and just do jumpers straight from the battery to the red and white will that take out any issues with the stator or rectifier as long as the trigger checks out tomorrow? Maybe I need many beers cause I can't stop thinking about this.
Cheers,
Nebraska
So anyways, it's a 78' 900 (90hp 2-stroke: serial #4846442) with an ignition switch box, single coil, and distributor. It had sat for ages in this places front yard by the state lakes, I remember it from when I was young and still living back on the farm. So as you can guess the wiring harness is trash, which over in indonesia I normally make my own but this guy has agreed to buy a new internal and to remote throttle harness but I'm trying to diagnosis it to see if I need to order anything else cause my time is limited in the states. So while trying to diagnose the spark issue i've had it running that many times, come out the next morning and it's no spark. So I'd tweak some things and it'd run again, but this last time I'm not sure what happened but it's weird. I've checked grounds between all straps, cleaned/sanded all the switchbox/coil/distributor terminals, wrapped and cleaned all the wire connections and it was running fine but I didn't want to push it since I didn't know when the last time the water pump was changed but it ran good (minus carb leaks but not a problem for the spark issue). The last time I didn't have spark, and this is where it gets weird, is that I read that grounding is a big issue and I added a alligator clip from the switch box (lower screw hole on the body) directly to the internal wire harness ground on the side cowling. I turned it over and it started on 5 cylinders (#1 shocked the hell out of me even though I was holding the boot and ground the plug to the frame bolt). So I installed the #1 spark plug and tried to start it again and the starter sounded like it was taking a huge load and going slow but then it kicked off and ran fine and I shut it down. But my alligator clip connection got super hot and after trying to start it again it actually popped???? I did a quick check test on the switch box and coil and had spark (standard red and white terminals had 12.4v, detach distributor leads and coil high tension wire, bridged the lower two distributor side terminals and grounded the top and got spark from the coil high tension wire against the block) so think the switch box and coil are good but didn't have time to try the distributor trigger cause I thought it need to be pulled but have since found out otherwise cause you can just turn the engine by hand. I'm heading back to the farm tomorrow so will do that test but still got no idea why that ground popped and I lost spark.
So that's where I'm at now so I'm trying to figure out at much as possible before getting my hands back on it. I've read so much up on this but some info is conflicting so that's why I'm posting... my long post haha. In video's I've watched and articles I've read, it appears that if you do the switch box/coil/trigger test it will just run! Other's say that a failed stator or rectifier can also kill the spark. I've already disconnected the mercury tilt switch to rule that out even though when it was hooked up it was still running. I found one article saying there is a "momentary" kill switch on the push/pull shift linkage (makes it easier to shift into gears) that can cause failure but I haven't been able to check since leaving the farm so not sure. Other say starter solenoid as well....
So I guess what I'm asking, does anyone know a complete list on what to check or rule out if not connected to spark issue? What I know or have read so far in my 50+ hours of research is below but need help confirming:
-12v or so to the red and white connections on the ignition switch box
-do a coil test by the above mentioned (remove distributor cables, bridge two lower on switch box, ground top, remove coil high tension and spark to block)
-rotor cap or spring and carbon brush (trigger test, which i haven't done yet)
-mercury tilt switch
-bad stator??
-bad rectifier??
-bad starter solenoid??
-"momentary" kill switch on push/pull shifting cable??
-grounds
-does it have a different kill circuit even if I have 12v at the red and white?
-others?
And also, say with my ignition switch box and coil test where I did get spark, do the ever intermediately go out or are they either good or bad? Same for when I check the trigger tomorrow?
I need a beer guys and I'm sure you're already thinking wtf after reading all this, it just keeps me up not knowing the answers. But again, if I disconnect everything from the switch box and just do jumpers straight from the battery to the red and white will that take out any issues with the stator or rectifier as long as the trigger checks out tomorrow? Maybe I need many beers cause I can't stop thinking about this.
Cheers,
Nebraska