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Heiaz,

I have an 97 TLS all stock with 19k miles maintenance made at 1k miles ago.
Last night heading home i've pushed a little going to 8/9000 rev until getting 130mph, then i felt the engine failing and i imediatly slowed down, i was near home it was night so i parked the bike and today in the morning i've started her up warmed up and went for a short ride around the block.
In idle if i rev her up, it doesn,t fail but it makes a little rattling noise between 3 and 4 rpm and with the engine running it doesnt desenvolve and seems it has no power like running on one cylinder only but both seems to be working...

What could it be? any electric problem? Engine problem? Can anyone give me some tips for a first diagnose? i know i should get her to the shop but before i wanted to see if i could see any major problem..

Thanks.
 

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Is the digital temperature gauge on the dash showing degrees F or degrees C? I'm assuming the engine was warm when you revved it. Perhaps the 130mph high rev run caused a little bit of oil to get spat up into the airbox from the breather tube. Stock 97 TLS's do that. If that oil made it down into a cylinder it could have fouled a spark plug, giving the symptoms you're seeing. Lift the tank, pull the air filter cover and look for oil residue around the left side of the inside of the airbox. If that's not it then maybe it could be related to the PAIR valve or a burst exhaust slip ring gasket at the swingarm?
how is it running? does it idle ok? If you start it from cold and let it idle, do the exhaust headers from both cylinders get hot evenly? any backfiring when decelerating? Worst case scenario would be a spun bearing, cracked piston or floated valve, but I think a fouled plug is way more likely. Let us know what you find in the airbox! Also check your oil level.
 

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There's a chance it could be a big end picking up and partially seizinng . This happened to me and a mate . . Both 97 s . . Does the engine make a knocking noise when under load . . Fingers crossed it's not that
 

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Is the digital temperature gauge on the dash showing degrees F or degrees C? I'm assuming the engine was warm when you revved it. Perhaps the 130mph high rev run caused a little bit of oil to get spat up into the airbox from the breather tube. Stock 97 TLS's do that. If that oil made it down into a cylinder it could have fouled a spark plug, giving the symptoms you're seeing. Lift the tank, pull the air filter cover and look for oil residue around the left side of the inside of the airbox. If that's not it then maybe it could be related to the PAIR valve or a burst exhaust slip ring gasket at the swingarm?
how is it running? does it idle ok? If you start it from cold and let it idle, do the exhaust headers from both cylinders get hot evenly? any backfiring when decelerating? Worst case scenario would be a spun bearing, cracked piston or floated valve, but I think a fouled plug is way more likely. Let us know what you find in the airbox! Also check your oil level.
The temp is in Celcius, i've checked air filter and both plugs all fine (see attachments), i didn't checked the pair valve because i didn't had more time today and im still very lame at mechanics, but im a curious :p, and the exhaust gaskets are ok.
When it runs, i seems like it has lost 40% of the power above 4.000 rpm and the knock/rattling dry noise becomes more audible, ill try to make a vid while running.
At idle, no problems.
She doesn't backfire.


Oil Filter.jpg plug 1.jpg Plug 2.jpg



There's a chance it could be a big end picking up and partially seizinng . This happened to me and a mate . . Both 97 s . . Does the engine make a knocking noise when under load . . Fingers crossed it's not that
Well, the sound it's louder when i ride it.. what other symptoms did you and your mate had?


Thanks for all your help :)
 

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Good thought, jagboy- knocking could be rod bearings. Overture, have you checked the fuel flow rate from the fuel pump? The loss of power at higher rpm could be weak fuel flow because of clogged filter or fading pump: http://www.tlzone.net/forums/help-forum/130666-tls-losing-power-5000-rpm.html

For the bearings, you can't just pull an oil pan and check them like on a car. I remember a quick and dirty old trick to checking rod bearings: Pull spark plug, rotate engine until piston is at Top Dead Center, continue past TDC just a little bit so piston has begun traveling down. Then stick a screwdriver through the spark plug hole and rest it on the center of the top of the piston- carefully avoiding the machined cylinder wall. Then, listen very closely and feel for any movement or clunking as you quickly push down on the screwdriver, trying to suddenly jab/push the piston down in the cylinder. The idea is that if the bearings are worn, there is a gap between the rod and crank, which causes the knock. This process moves the gap to the top of the crankshaft, then the push suddenly moves the gap to the bottom of the crank, and you would be able to hear/feel that movement. this trick tries to locate the knock without splitting any engine case open.

Your knock isn't very loud and not constant so that trick might not even be accurate enough to find it, even if it IS rod bearings. Rod knock becomes very obvious at higher revs when you get on the gas.
 

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double post.
 

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If your rod big end bearings are bad enough to knock, you should be able to drain the oil and filter it thru a piece of cloth, and see how much copper-colored bearing material is in the oil, then cut open the oil filter and flush it out with the filtered oil and filter that thru cloth too. If you pounded the bearing hard enough to knock and lose power, you'll probably find lots of the bearing material somewhere.

You might be able to rotate the crank until the piston is going down, then push it with a dowel thru the spark plug hole, and see if it's got some play and lands with a clunk.

Anyone who's experienced a rod knock can recognize it, as it's a deeper knock than valves because it's larger parts, and more frequent because it happens once per rev whereas valves run at half that speed. And rod knock comes and goes with changes to load & rpm until it gets really bad and really constant.

Try not to run it, 'cause if it is the rod big-end bearing you don't want to destroy your crank throw journal.
 
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