Welp, good news {at least for me}. The bike is running again but the bad news is we don't really know exactly why it crapped out. The mechanic decided to de-carbon the interior of the ports with some carb cleaner type of stuff pretty much like Sea Foam and left it to soak overnight. The next day he squirted some oil in each cylinder, buttoned everything up, cranked it over with 24Vs and hit it with some ether. It started and ran,,,,, and will do repeatedly as normal.
Honestly I don't think anyone knows exactly what happened but I think I've got a decent hypothesis. The previous owner had installed a gear indicator and a some crazy looking woo loo lights {green neon lookin crap} and he tapped into the harness right before it connects to the computer and he did the tapping with some hooky no solder wire taps. He also busted the little clip thing that keeps the wiring harness connector attached to the computer. Possibly,,, possibly one those taps grounded, lost continuity or whatever and killed the electrical. Possibly,,, {once again with that possibly thing} the connector pulled ever so slightly loose from the computer just enough to make an open circuit. I asked the mechanic to de-install that crap. In any event,, the engine shut completely down so I'm pretty sure it was an electrical problem preventing ignition or fueling.
I think that continually cranking the thing scrapped all the oil from the cylinder walls and that contributed to the low compression possibly {remember, that has actually happened to me so I know it happens}. The mechanic still stands by his assertion that it was losing compression past the valves? His assertion was that carbon build up ran down between the valve and the seat while we were doing all that cranking and that is what held the valves off their seat resulting in low compression. Which opinion is right??? Dunno,,,, prolly a bit of both maybe????
Maybe sometime during the trouble shooting, the electrical problem went away due to me or him wiggling wiring trying to check fuses and connections and that is why it had both spark and fuel when he got around to checking it. Then,,,, possibly the lack of compression reared it head and Murphy had a field day with me and everyone else that was trying to figure this crap out.
I'm still not buying the deposit thing as the initial problem because it started and ran as normal. No way deposits could have made it's way to each cylinder and held at least one valve open because the engine shut down completely as if you hit the kill switch. Now possibly,,,,, sometime after the initial problem shut the engine down, deposits made their way down and did indeed throw a monkey in the wrench. Aggravating and confusing as all get out and I hope I don't have this again. For some reason, I have a knack for having weird, complicated mechanical problems jump my arse. Oh, well,,,, ya live and ya learn. Well,,,, didn't learn much this time, at least nothing concrete and that sorta sucks. I was hoping to have some grand remedy to give ya'll and be able to help the next FJR owner out but I honestly think that this whole ordeal was a result of a multiple issues and I can't really point to any one of those issues with any degree of certainty and say that was the problem.
I have to hand it to the mechanic, this was a hair puller and even though he had his opinions he also was willing to keep an open mind and kept trying to fix the problem no matter where the ideas came from. Not many mechanics will do that and I think that is what makes the difference between a mediocre mechanic and a really good one.
It still needs some gaskets and a few other things done but at least it is now cranking and starting. Should get it back by the middle of next week. Oh, BTW,,,,, the valve clearances were fine. So,,, after 37K miles the Yamaha valve train was still in tolerance. Not too shabby I reckon.
Honestly I don't think anyone knows exactly what happened but I think I've got a decent hypothesis. The previous owner had installed a gear indicator and a some crazy looking woo loo lights {green neon lookin crap} and he tapped into the harness right before it connects to the computer and he did the tapping with some hooky no solder wire taps. He also busted the little clip thing that keeps the wiring harness connector attached to the computer. Possibly,,, possibly one those taps grounded, lost continuity or whatever and killed the electrical. Possibly,,, {once again with that possibly thing} the connector pulled ever so slightly loose from the computer just enough to make an open circuit. I asked the mechanic to de-install that crap. In any event,, the engine shut completely down so I'm pretty sure it was an electrical problem preventing ignition or fueling.
I think that continually cranking the thing scrapped all the oil from the cylinder walls and that contributed to the low compression possibly {remember, that has actually happened to me so I know it happens}. The mechanic still stands by his assertion that it was losing compression past the valves? His assertion was that carbon build up ran down between the valve and the seat while we were doing all that cranking and that is what held the valves off their seat resulting in low compression. Which opinion is right??? Dunno,,,, prolly a bit of both maybe????
Maybe sometime during the trouble shooting, the electrical problem went away due to me or him wiggling wiring trying to check fuses and connections and that is why it had both spark and fuel when he got around to checking it. Then,,,, possibly the lack of compression reared it head and Murphy had a field day with me and everyone else that was trying to figure this crap out.
I'm still not buying the deposit thing as the initial problem because it started and ran as normal. No way deposits could have made it's way to each cylinder and held at least one valve open because the engine shut down completely as if you hit the kill switch. Now possibly,,,,, sometime after the initial problem shut the engine down, deposits made their way down and did indeed throw a monkey in the wrench. Aggravating and confusing as all get out and I hope I don't have this again. For some reason, I have a knack for having weird, complicated mechanical problems jump my arse. Oh, well,,,, ya live and ya learn. Well,,,, didn't learn much this time, at least nothing concrete and that sorta sucks. I was hoping to have some grand remedy to give ya'll and be able to help the next FJR owner out but I honestly think that this whole ordeal was a result of a multiple issues and I can't really point to any one of those issues with any degree of certainty and say that was the problem.
I have to hand it to the mechanic, this was a hair puller and even though he had his opinions he also was willing to keep an open mind and kept trying to fix the problem no matter where the ideas came from. Not many mechanics will do that and I think that is what makes the difference between a mediocre mechanic and a really good one.
It still needs some gaskets and a few other things done but at least it is now cranking and starting. Should get it back by the middle of next week. Oh, BTW,,,,, the valve clearances were fine. So,,, after 37K miles the Yamaha valve train was still in tolerance. Not too shabby I reckon.
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