TLZone Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Hello all. Newbie here. I have a 1997 TLS with 12,000 miles. Nice condition. Pulled up the drive from a completely un-eventful ride, turned the motor off,- clutch in, clicked into neutral, sidestand down and got off.
2 hours later, I went to put it away, and turned the ignition on, hit the starter and all I got was a clicking from under the seat.
OK...so I went through ALL the motions of "first options"..relay, starter...blah blah.
Eventually leading me to a deeper problem perhaps. I removed the LH crank cover and manually tried to crank the motor. It reaches a point, then hits a hard stop.
My first thought was a timing issue, maybe caused by a jumped timing chain, then getting a dinged valve.
I pulled the rear plug and with a wood dowel, I cranked to determine that the piston is reaching and peaking TDC, but the motor hits a hard stop just at that point of rear peaking over TDC. Timing chains, decomp, tensioners all look in fantastic shape. Putting a rubber stopper on the end of the dowel and cranking, I'm getting compression, making me understand that there is no issue with valves not seating.
Moving to the front, I removed the radiator and front plug, and repeated the same procedure. In the case of the front, the piston will not reach TDC before the hard stop is felt. The stumper is this. Using the same procedure with the rubber stopper, I am getting compression. The timing chains, tensioners, decomps...all look in fantastic shape. Since I'm getting compression, it follows that there is no issue with the valves seating.
I can only conclude that it is not an issue with the top end, unless ANYBODY can help me with knowledge of a similar scenario!
 

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,342 Posts
Welcome to the Zone!

How you are able to do this 'compression test' when the engine "hits a hard stop" in its rotation is a little confusing.

Given the initial symptoms, I would rather suspect a failed battery, poor connection, or a failed charging system.
How did you rule out these possibilities?
 

·
Registered
Joined
·
10 Posts
Discussion Starter #3
Thanks for the reply six5. OK. so...the bottom line is this. MECHANICALLY the motor will not rotate through 1 full rotation. If you start with the motor at hard stop and rotate CCW, the rear piston appears to be on compression stroke. (The valve covers are off on both so I can see cam position) Holding the rubber stopper in the plug hole, as you rotate CCW, you get pressure release around the stopper. The rear piston peaks at TDC and is now ready to head down on power stroke. At this point, you get a hard stop. (Remember the plugs are out)
Now..rotating the motor CW to return to start point before, the front piston is now moving upward, and I'm getting pressure release around the rubber stopper, which tells me I'm getting compression, am I wrong?
The stumper is that the front piston does not reach TDC before the hard stop.
Initially, that would indicate an open valve preventing the piston reaching TDC. But if that were the case, I shouldn't be getting pressure in the cylinder on the up stroke. And as I said...the top ends on both appear great.
I'm not following how you figure this being an electrical problem? -P
 

Attachments

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,342 Posts
Thanks for the additional description of your compression test.

I'm just having difficulty imagining what could fail that would cause a mechanical "hard stop" ......when it was running fine and you merely turned off after a ride. Very odd.

On the other hand, I can completely see how a charging system failure during the ride would cause the 'no start' condition you experienced later. It happened to me...... effectively twice.

First occurrence: I started and rode my TLR to a destination 2 miles away. Turned off the bike when I got there. Twenty minutes later, I attempted start it, but was greeted with dim lights and a very faint relay click. I found the battery had failed (it was only days old). A shorted or open cell IDK, but it had no power. It was toast.
Yours may not be so obvious, but a low battery charge or resistive connection is the classic cause of the 'relay click' you heard.
Note: If the starter relay were actually delivering current to the starter motor, but the engine couldn't spin due to the "hard stop," then the starter cables would get very warm very quick. Was that the case?

Second occurrence: The fuse holder between the regulator and battery failed during the ride. The fuse holder became resistive. Therefore, the battery was no longer being charged via the stator/rectifier/regulator system. Eventually, the system shut down because the battery ran out of charge.
It could be that something similar happened to yours, but you were able to get back home before the discharge was low enough to prevent the ECM from functioning.

it is very difficult to troubleshoot failures like this via the internet, but I think your charging system is worth a look. That is, when you are satisfied that you can spin the engine over mechanically.

Keep us posted please.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #6
Taking a late lunch to check in. Thank-you for your time and input,- really.
You're right...this over-the-internet diagnostic really is impossible.
After sorting the initial obvious electrical issues, new relay, rebuilt the starter, spins like a 2hp top, fuses, leads, connections...it just led me to think it's something else, so that's when I decided to hand crank the motor and discovered this hard stop.
I have a question. Has anybody reported the issue of perhaps a decomp malfunction on motor stop to accidentally hold the exhaust valve open as the motor is on it's last stroke. I'm thinking,- thus causing a valve ding? The front cylinder valves look to be seated and returned just fine. (I have the cams and shims out). BUT...I know looks could be deceiving. Has this ever been reported as an issue? I'm trying to avoid tearing the front top end off, but if that is the next logical step..I gotta do it.
The only other logical option I can thing of...is that it's something in the bottom end of the rear cylinder. Gearbox failure? but then why at motor shut-down?
Frustrating. I had searched the blogs and posts a couple of months back when this happened, and the scenario of not starting after shut-down for an hour was common. But I felt I did eliminate electrical probabilities, and started looking deeper.
My gut is telling me a piston strike in the front cyl. but other factors indicate otherwise. Damn.
Maybe I should just buy a motor off Ebay and swap it out? I'm getting more of a stink-eye and cold shoulder from the missus too. Gotta fix this.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #7
Thanks for the additional description of your compression test.

I'm just having difficulty imagining what could fail that would cause a mechanical "hard stop" ......when it was running fine and you merely turned off after a ride. Very odd.

On the other hand, I can completely see how a charging system failure during the ride would cause the 'no start' condition you experienced later. It happened to me...... effectively twice.

First occurrence: I started and rode my TLR to a destination 2 miles away. Turned off the bike when I got there. Twenty minutes later, I attempted start it, but was greeted with dim lights and a very faint relay click. I found the battery had failed (it was only days old). A shorted or open cell IDK, but it had no power. It was toast.
Yours may not be so obvious, but a low battery charge or resistive connection is the classic cause of the 'relay click' you heard.
Note: If the starter relay were actually delivering current to the starter motor, but the engine couldn't spin due to the "hard stop," then the starter cables would get very warm very quick. Was that the case?

Second occurrence: The fuse holder between the regulator and battery failed during the ride. The fuse holder became resistive. Therefore, the battery was no longer being charged via the stator/rectifier/regulator system. Eventually, the system shut down because the battery ran out of charge.
It could be that something similar happened to yours, but you were able to get back home before the discharge was low enough to prevent the ECM from functioning.

it is very difficult to troubleshoot failures like this via the internet, but I think your charging system is worth a look. That is, when you are satisfied that you can spin the engine over mechanically.

Keep us posted please.
Taking a late lunch to check in. Thank-you for your time and input,- really.
You're right...this over-the-internet diagnostic really is impossible.
After sorting the initial obvious electrical issues, new relay, rebuilt the starter, spins like a 2hp top, fuses, leads, connections...it just led me to think it's something else, so that's when I decided to hand crank the motor and discovered this hard stop.
I have a question. Has anybody reported the issue of perhaps a decomp malfunction on motor stop to accidentally hold the exhaust valve open as the motor is on it's last stroke. I'm thinking,- thus causing a valve ding? The front cylinder valves look to be seated and returned just fine. (I have the cams and shims out). BUT...I know looks could be deceiving. Has this ever been reported as an issue? I'm trying to avoid tearing the front top end off, but if that is the next logical step..I gotta do it.
The only other logical option I can thing of...is that it's something in the bottom end of the rear cylinder. Gearbox failure? but then why at motor shut-down?
Frustrating. I had searched the blogs and posts a couple of months back when this happened, and the scenario of not starting after shut-down for an hour was common. But I felt I did eliminate electrical probabilities, and started looking deeper.
My gut is telling me a piston strike in the front cyl. but other factors indicate otherwise. Damn.
Maybe I should just buy a motor off Ebay and swap it out? I'm getting more of a stink-eye and cold shoulder from the missus too. Gotta fix this.
 

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,342 Posts
......
Has anybody reported the issue of perhaps a decomp malfunction on motor stop to accidentally hold the exhaust valve open as the motor is on it's last stroke. I'm thinking,- thus causing a valve ding? ...
Unlikely. Plus, I have never read about such an issue after 20 years of lurking on these forums.


The front cylinder valves look to be seated and returned just fine. (I have the cams and shims out). BUT...I know looks could be deceiving. Has this ever been reported as an issue? .....
The only other logical option I can thing of...is that it's something in the bottom end of the rear cylinder. Gearbox failure? but then why at motor shut-down?
........
My gut is telling me a piston strike in the front cyl. but other factors indicate otherwise. ....
Now, with the cams removed, there is nothing to actuate the valves, so the springs will keep them closed all the time. Therefore, it's a good time to rotate the engine to see if you still run into a hard stop.

If it spins freely, you'll know that the bottom end is clear and not causing the problem.

If it still runs into a stop, try disengaging the clutch, and spin it again. If it then spins freely, you might then suspect a transmission problem.

If it still runs into a stop, even with the clutch disengaged, you can then remove the right side engine cover to inspect the gears between the crank clutch and transmission. This might offer up a clue.
 

·
Registered
Joined
·
10 Posts
Check the crankshaft end nut - TL motors had a bad habit of the nuts coming loose leading to a poor meshing of the backlash gears. I had mine making an occasional clunk noise similar to chain slap on the swingarm. After a full engine strip a Suzuki mechanic told me to check the nut - voila - loose by about 16th of a turn.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #10
Unlikely. Plus, I have never read about such an issue after 20 years of lurking on these forums.




Now, with the cams removed, there is nothing to actuate the valves, so the springs will keep them closed all the time. Therefore, it's a good time to rotate the engine to see if you still run into a hard stop.

If it spins freely, you'll know that the bottom end is clear and not causing the problem.

If it still runs into a stop, try disengaging the clutch, and spin it again. If it then spins freely, you might then suspect a transmission problem.

If it still runs into a stop, even with the clutch disengaged, you can then remove the right side engine cover to inspect the gears between the crank clutch and transmission. This might offer up a clue.
Great thought. I've convinced myself that this hard stop is not in the top end. I'll put all that back together (if I don't, I'll never remember where it all goes) then I'll investigate gear issues. I'll keep all posted on discoveries. Thanks again.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #11
Check the crankshaft end nut - TL motors had a bad habit of the nuts coming loose leading to a poor meshing of the backlash gears. I had mine making an occasional clunk noise similar to chain slap on the swingarm. After a full engine strip a Suzuki mechanic told me to check the nut - voila - loose by about 16th of a turn.
Yup. Crank and gears are my next areas of poke and prod. I'll keep all posted. Thx.
 
1 - 11 of 11 Posts
Top