Overheating Mystery Solving 2016 FJR
Posted: Fri Jun 16, 2023 8:45 pm
I posted this on FJROwners also. I wasn't quite sure if this should be in the "I Have a Complaint" thread, or maybe later in the Good News thread. Well it is kinda technical, so here we go.
An interesting story to tell, I'll give you details but try not to hold you in suspense too much. The answer is rather unbelievable. I have a lot of FJR experience with my own FJR's and from the many years of FJR tech days I've had, and even here many think I know all things FJR (and I thank you for the many compliments), but this one's a new one on me. Old, but never too old to learn something. I'm frustrated and pissed, partly because I couldn't solve the problem and well, you'll see why.......
Background, 2016 FJR with trans recall performed @55-something k kms. Current mileage just over 56 k kms, it really hasn't gone far at all. Buddy J was riding from here to Ohio for an annual event we have, we get a call..... broken down, gonna be late...... bike overheated and spewed out a bunch of coolant. When it cooled down, filled the rad and started the bike, didn't take too long when it boiled over again..... had it towed to a local dealer, but too late to get it in for a look..... we have a trailer, so I gladly go pick him up there. We get to the event after dark, unload the bike so we can work on it in the parking lot in the morning. While I wait, I check with parts department and no thermostats in stock, apparently have to come from Japan, which will take around 3 weeks.
Bike in the parking lot on a nice 70 degree day. Refilled rad and observed air purge, just about to put cap back on when it boiled over again. Hmmm..... we call another dealer hoping they have a thermostat in stock, but no luck, same 3 week wait from Japan...... We drive to local town 40 miles away and see if we can match up something at local auto supply..... we got one kinda close, but not ideal..... removed side fairing and got old one out, tested it in boiling water and later in water not quite so hot.... thermostat looked like new, no problem going to full open and partially open at lower temp..... no evidence of sticking..... hmmmmm. We could run with no thermostat except for the gasket design requiring the metal to be there... we could pull the guts out of the thermostat.... OK let's not for the moment, it tested OK, so put it back in.
What else could it be?? Water pump or blockage about the only other thing it could be. Coolant drained and removed water pump, I love crawling around on asphalt at this age, NOT. Verified water pump turns freely, impeller good, looks like new, never leaked. Attempted to turn the key that drives the water pump, could not, so assumed the drive (oil pump shaft) was OK. Put it all back together, refilled slowly and could not see any evidence of blockage... if blocked we wouldn't have been able to put the full amount of coolant in..... there is a bleed hole in the thermostat, and when filled that far, it seemed to bleed... regardless, it's normal there is very likely some air trapped in the U-shaped part between thermostat and coolant pipe in the head...... ran it to purge air while noting the temperature rise in the display..... the thermostat we believe was opening, but never got the flow or bubble of air..... put the cap on with rad full. Fans eventually kicked on but could not reduce the temperature.... it kept rising and eventually displayed 'HI' and we immediately shut it down.
Let it cool down and noted the drop in the coolant reservoir, which means coolant was sucked back in to replace air. Perfect, now with known full system, we run it again to note temperature change. Same deal, fans come on, and it eventually goes to HI. Shut it down, and when cool, note reservoir level has not changed. Perfect again and totally expected result.
Went for a test ride to ensure lots of air flow through the rad..... didn't help. Fans came on, temp eventually went to HI and blew out some coolant. Something else is wrong and we shut it down until we could get it to my shop.... next day, 9 hour drive to my place, I'll get to it in the morning......
I got the right fairing propped out to get access to the clutch cover and timing cover, removed those. I observed the oil pump chain was not broken, and turned the engine over at the timing end.... oil pump chain did not move. WHY?
Removed the clutch completely. Note, the oil pump sprocket has 4 dogs on it that engage in the back of the main clutch housing. I see damage and wear marks on the clutch housing, I see worn off oil pump sprocket dogs and burrs. With the oil pump sprocket still in place, I can spin the oil pump/water pump to confirm it is not locked up.
Once I got the oil pump sprocket off, there I was staring right at the transmission bearing. I see two grooves (highlighted in red) worn into the transmission bearing retainer by the oil pump chain, and wonder how that oil pump sprocket was allowed to travel inward so far. I held a mirror to the back side of the chain and see where the links are worn. What would pressure the oil pump sprocket into the transmission bearing area? This pic with sprocket removed, but when sprocket on the chain lines up with the worn-in grooves.
What has happened is, the oil pump sprocket travelled inward until it disengaged from the ramps on the mating recesses in the clutch housing, then somewhere along the line it got jammed, the clutch housing would spin and grind material off the sprocket dogs, resulting in burning and burrs, and would eventually not allow the sprocket dogs to re-engage. With the oil pump stopped there would be no oil pressure nor water pump driven. Worse, there would be no indication whatsoever until it eventually boiled over.
Note, the FJR does not have any oil pressure indicator or warning light. There is only an oil level sensor to let you know in the unlikely event you're low in oil....... if there was any indication oil pressure was a problem, the answers would have come a lot sooner.
Burned and burred oil pump sprocket, dogs worn off, and wear marks on the clutch housing.
Immediately I wondered why no spacer behind the oil pump sprocket. A quick check of the service manual and parts list reveals two missing parts...... a conical spring washer and a stepped spacer, see items 18 and 19 in the clutch diagram (oil pump sprocket shown in the oil pump diagram). The measured thicknesses all add up...... the spring washer pushes the spacer against the oil pump sprocket to keep the dogs engaged in the clutch housing at all times.
These items were removed during the transmission recall and not reinstalled (there is an instruction in the trans replacement procedure). Unmistakenly and clearly the dealer mechanic missed this step.
What also disturbs me greatly is the internal wear on engine parts that depend on oil pressure (cams, cylinder head, crank and rod bearings, cylinder walls). The engine will likely have to be further disassembled to determine the extent of that. Parts replacement initial list includes the two missing parts, a new oil pump sprocket and bearing, oil pump chain and a new clutch housing...... we're into the thousands of dollars. To me, it is smarter and better to simply drop in a new engine. That's going to be a big discussion.....
While I am sickened and dismayed, I empathise with the dealer but nevertheless, it is definitely his responsibility to step up. I know we've had a couple engine failures and replacements resulting from the recalls, and I believe Yamaha stepped up also.
My buddy is in discussion, meanwhile I have the bike on my lift awaiting direction........
An interesting story to tell, I'll give you details but try not to hold you in suspense too much. The answer is rather unbelievable. I have a lot of FJR experience with my own FJR's and from the many years of FJR tech days I've had, and even here many think I know all things FJR (and I thank you for the many compliments), but this one's a new one on me. Old, but never too old to learn something. I'm frustrated and pissed, partly because I couldn't solve the problem and well, you'll see why.......
Background, 2016 FJR with trans recall performed @55-something k kms. Current mileage just over 56 k kms, it really hasn't gone far at all. Buddy J was riding from here to Ohio for an annual event we have, we get a call..... broken down, gonna be late...... bike overheated and spewed out a bunch of coolant. When it cooled down, filled the rad and started the bike, didn't take too long when it boiled over again..... had it towed to a local dealer, but too late to get it in for a look..... we have a trailer, so I gladly go pick him up there. We get to the event after dark, unload the bike so we can work on it in the parking lot in the morning. While I wait, I check with parts department and no thermostats in stock, apparently have to come from Japan, which will take around 3 weeks.
Bike in the parking lot on a nice 70 degree day. Refilled rad and observed air purge, just about to put cap back on when it boiled over again. Hmmm..... we call another dealer hoping they have a thermostat in stock, but no luck, same 3 week wait from Japan...... We drive to local town 40 miles away and see if we can match up something at local auto supply..... we got one kinda close, but not ideal..... removed side fairing and got old one out, tested it in boiling water and later in water not quite so hot.... thermostat looked like new, no problem going to full open and partially open at lower temp..... no evidence of sticking..... hmmmmm. We could run with no thermostat except for the gasket design requiring the metal to be there... we could pull the guts out of the thermostat.... OK let's not for the moment, it tested OK, so put it back in.
What else could it be?? Water pump or blockage about the only other thing it could be. Coolant drained and removed water pump, I love crawling around on asphalt at this age, NOT. Verified water pump turns freely, impeller good, looks like new, never leaked. Attempted to turn the key that drives the water pump, could not, so assumed the drive (oil pump shaft) was OK. Put it all back together, refilled slowly and could not see any evidence of blockage... if blocked we wouldn't have been able to put the full amount of coolant in..... there is a bleed hole in the thermostat, and when filled that far, it seemed to bleed... regardless, it's normal there is very likely some air trapped in the U-shaped part between thermostat and coolant pipe in the head...... ran it to purge air while noting the temperature rise in the display..... the thermostat we believe was opening, but never got the flow or bubble of air..... put the cap on with rad full. Fans eventually kicked on but could not reduce the temperature.... it kept rising and eventually displayed 'HI' and we immediately shut it down.
Let it cool down and noted the drop in the coolant reservoir, which means coolant was sucked back in to replace air. Perfect, now with known full system, we run it again to note temperature change. Same deal, fans come on, and it eventually goes to HI. Shut it down, and when cool, note reservoir level has not changed. Perfect again and totally expected result.
Went for a test ride to ensure lots of air flow through the rad..... didn't help. Fans came on, temp eventually went to HI and blew out some coolant. Something else is wrong and we shut it down until we could get it to my shop.... next day, 9 hour drive to my place, I'll get to it in the morning......
I got the right fairing propped out to get access to the clutch cover and timing cover, removed those. I observed the oil pump chain was not broken, and turned the engine over at the timing end.... oil pump chain did not move. WHY?
Removed the clutch completely. Note, the oil pump sprocket has 4 dogs on it that engage in the back of the main clutch housing. I see damage and wear marks on the clutch housing, I see worn off oil pump sprocket dogs and burrs. With the oil pump sprocket still in place, I can spin the oil pump/water pump to confirm it is not locked up.
Once I got the oil pump sprocket off, there I was staring right at the transmission bearing. I see two grooves (highlighted in red) worn into the transmission bearing retainer by the oil pump chain, and wonder how that oil pump sprocket was allowed to travel inward so far. I held a mirror to the back side of the chain and see where the links are worn. What would pressure the oil pump sprocket into the transmission bearing area? This pic with sprocket removed, but when sprocket on the chain lines up with the worn-in grooves.
What has happened is, the oil pump sprocket travelled inward until it disengaged from the ramps on the mating recesses in the clutch housing, then somewhere along the line it got jammed, the clutch housing would spin and grind material off the sprocket dogs, resulting in burning and burrs, and would eventually not allow the sprocket dogs to re-engage. With the oil pump stopped there would be no oil pressure nor water pump driven. Worse, there would be no indication whatsoever until it eventually boiled over.
Note, the FJR does not have any oil pressure indicator or warning light. There is only an oil level sensor to let you know in the unlikely event you're low in oil....... if there was any indication oil pressure was a problem, the answers would have come a lot sooner.
Burned and burred oil pump sprocket, dogs worn off, and wear marks on the clutch housing.
Immediately I wondered why no spacer behind the oil pump sprocket. A quick check of the service manual and parts list reveals two missing parts...... a conical spring washer and a stepped spacer, see items 18 and 19 in the clutch diagram (oil pump sprocket shown in the oil pump diagram). The measured thicknesses all add up...... the spring washer pushes the spacer against the oil pump sprocket to keep the dogs engaged in the clutch housing at all times.
These items were removed during the transmission recall and not reinstalled (there is an instruction in the trans replacement procedure). Unmistakenly and clearly the dealer mechanic missed this step.
What also disturbs me greatly is the internal wear on engine parts that depend on oil pressure (cams, cylinder head, crank and rod bearings, cylinder walls). The engine will likely have to be further disassembled to determine the extent of that. Parts replacement initial list includes the two missing parts, a new oil pump sprocket and bearing, oil pump chain and a new clutch housing...... we're into the thousands of dollars. To me, it is smarter and better to simply drop in a new engine. That's going to be a big discussion.....
While I am sickened and dismayed, I empathise with the dealer but nevertheless, it is definitely his responsibility to step up. I know we've had a couple engine failures and replacements resulting from the recalls, and I believe Yamaha stepped up also.
My buddy is in discussion, meanwhile I have the bike on my lift awaiting direction........
