Tiger not starting after riding for a while

[BykBoy]

when the sensor failed on the wifes steamer we could get it running right away by pouring cool water on the case and it would be just enuff to drop the temp and let it start and run for about 5-10 minutes before it would die again , took about a half a dozen times to get it home instead of on the side of the road . that's how I determined it was the sensor .

I don't think this is the same issue. Mine has a hard time starting, but one it starts, it runs fine and does not shut down by itself.

That's why this is so puzeling...

[BykBoy]

I assume you have checked the oil recently.  How old is the oil and does it smell like fuel.  The symptoms are indicative of hot oil failure.  Could be a ton of other things but the oil could do it.

I did not specifically check the oil, but I change the oil regularly... I"ll try smelling for fuel...

[BykBoy]

Well, after a valve adjustment, replacing the water temp sensor, replacing all the crank sensor, and replacing the ECU, this ended up being a bad Sprag clutch (a $450 for the part...).

Old Sprag assembly on the left.


Old Sprag on top


Open Clutch and Sprag covers without Clutch and Sprag.


New Sprag in place.

[TigerTrax]

If that was the problem... I am scratching my head.

Q: Why would the sprag clutch fail to engage when the motor is hot?

[BykBoy]

The sprag clutch was still functioning. However, it was not turning smothly. When I turned it by hand, it felt as if something was grinding inside.

My best guess is that the sprage would slip when it got hot. This would explain the differnt sound the comming from the starter. As the sprag slips, it can not crank the motor and the ignition process fails. That's my guess...

I spoke to a master mechanic and he said the sprag should not be blue. It should be shiny. As you can see from the picture, the old sprag is not shiny...

[Bixxer Bob]

I'm heartened to see it's not an engine out job to do the sprag clutch on on a 955.  I had a 900 Trident and it was a BIG job, fortunately done under warranty.

Is it as straight forward on a steamer, or is it like my old Trident,  engine out and full strip?

[Mustang]

I'm heartened to see it's not an engine out job to do the sprag clutch on on a 955.  I had a 900 Trident and it was a BIG job, fortunately done under warranty.

Is it as straight forward on a steamer, or is it like my old Trident,  engine out and full strip?

Unless you have an early steamer that has the access cover it's engine out case splitting time ! Woo Hoo !

[Bixxer Bob]

Glad I've got a Girly then...  

Not so good though, a friend has a dead steamer due to a sprag clutch and can't afford the labour charges.  I offered to do it for him over the winter if he can get it to me in a van or something.   Like I need the work....  :roll:

Sorry about temporarily hijacking the thread by the way.  He's the sort of guy that's not practical with is hands, but you don't mind helping out.  He has an early hard-tail Triumph which had a rear drum brake flange that was rotted through a while back.  Some ham-fisted idiot ruined it with a stick welder trying to build it back up.  My friend was in despair, because he'll never find a spare, until I noticed the rotten flange, and most of the rubbish weld, was was spot welded to the main brake backplate.  Although it had an awkward joggle in it, I thought we might have a chance, so, after making up a makeshift wood lathe from an old bacon slicer motor and a faceplate I turned up a hardwood press tool.  I then cut out and fashioned a new flange.  I didn't have a press to do the joggle with the press tool, so I jacked up the car, put the whole thing under the diff and let the jack down,  that did the trick.  Finally,  when I was sure it was right,  I ground the old flange off and spot welded the new one on.  A coat of paint later it was as good as new.  

Overcoming the challenge, and the look of absolute wonder on his face, was thanks enough, but he bought me a shed-load of beer as well  :lol:

[Stretch]

Yep, improvisation is the life-blood of the shade-tree mechanic.

Just today I saved myself a couple hundred bucks by building my own manometer (carb / throttle body synchronizer) out of vinyl tubing, scrap lumber, zip ties, and automatic transmission fluid.  I'll post pics later.

[Bixxer Bob]

Grand job Stretch, I'm guessing you're using three equal tubes with the transmission fluid in a u bend of some sort?

Did you use science to be sure you didn't suck fluid into the carbs the first time you used it, or just care and guesswork?

[abruzzi]

Just today I saved myself a couple hundred bucks by building my own manometer (carb / throttle body synchronizer) out of vinyl tubing, scrap lumber, zip ties, and automatic transmission fluid.  I'll post pics later.

I thought my manometer was to measure my manliness.  I guess I've ben using it wrong.

Geof

[Stretch]

Did you use science to be sure you didn't suck fluid into the carbs the first time you used it, or just care and guesswork?

Care and guesswork.  But mostly just the guesswork.  


I built it with four tubes, on the offhand chance I'll need to synch the carbs on a four-cylinder bike some time.  The fifth tube (far left) is the vent tube, which is open to the ambient air.

It's not perfected for fuel-injected Tigers yet, though.  The Idle Air Controller bolted to the fuel rail regulates the amount of air meted to each throttle body at idle.  The throttles themselves are completely closed at idle, so all the air used by the engine at idle comes only from those ports (one port per throttle body).

So... the vacuum pulse at each vacuum port isn't just a by-product of the engine vacuum at idle (venturi effect, etc).  It is the engine vacuum at idle.  No amount of restriction in the manometer tubes will keep the throttle ports from sucking in the oil.

So, I get to build a few adapters that I can plug onto the vacuum ports, which allow the engine to pull what it needs through the ports, while delivering a measurable vacuum for the manometer.  Essentially, a small venturi that the manometer can plug in to in order to get a bit of vacuum, but not all of it.

[Bixxer Bob]

Did you use science to be sure you didn't suck fluid into the carbs the first time you used it, or just care and guesswork?

Care and guesswork.  But mostly just the guesswork.  

  My approach too......  basically a calculated risk, intelligently taken  :lol:

[iansoady]

I haven't got around to doing this yet but was under the impression that you need to use the throttle stop to crack the throttles open slightly so that the air for combustion is going past the butterflies rather than through the bypass. If you think about it, if the butterflies are completely closed how can you synchronise them?

[Stretch]

That makes sense.  That way, the one(s) that are opening a bit too early will show a lower vacuum.

#1 (far left) is the 'control', the one that the other two are compared to.  So if 2 or 3 were showing high or low vacuum compared to #1, 2 or 3 would be the ones to be adjusted in order to bring all three into the same readings.