Hello everyone. Someone on the triumph rat forum recommended I try this place out. I'm the proud owner of a new to me 1999 speed triple 955i @ 21k miles, that has sadly and very suddenly developed a loud knocking sound yesterday morning as I exited the interstate. The engine will still crank and run. I didn't want to run it under load so I trailered it home. There are no visible particles in the drained oil. I hope its not a spun bearing. No shops within 100 miles will even look at it. I'm sad but ready for the challenge with assistance from you folks. I need some advice for diagnosing the issue. Are there things i can check other than the oil, with the engine still in the bike or should i go ahead and start disconnecting it from the bike? Check out this short video clip of the sound after the bike cooled off and i breifly restarted it..
Well that sounds like the engine may not be toast. Great! Can that be diagnosed with the engine mounted on the frame?
1true Yes it is harder but doable. Get a bit of wood and listen around the right side of the head and barrels see if it really is the head. Does the bike have any service history at all. As it may need the shims doing and in that case get it done asap as you may have a valve hitting a piston. Regards Joe.
Okay, well if valves may be making contact with the piston or bearings are possibly being pummeled into delicate surfaces, I don't think I should run it long enough to get it warm enough to idle without throttle assistance (cold start issue before all this) so that i can figure out if i trust my ears enough to hear whats going on inside a box I can't visualize. I was thinking I might remove some easily accessible covers and have a look but wasn't sure if I would see anything or if some magically folded collection of springs and gears may fly out and never go back in if the engine wasn't on its side. LOL. No service history
Hmm, no amount of wear on the shims should cause the valves to contact the pistons. It certainly sounds top end though. It's not unheard of for the spark plugs to lose a tip so it would be good to whip them out and take a look. Little ends can also be an issue but that usually comes on slowly and the noise is less dramatic. I'd remove the tank and airbox then the spark plugs and then the cam cover. These engines have the big shims that sit on top so it might be possible that one has slipped out, (unlikely I'd have thought but worth a check).
Tail, tank and airbox out. Fuel lines and coil wires marked. Off to find either an18mm deep well, thin wall socket to release these plugs.
All 3 plugs are fully intact. Only place open Autozone had what I needed to remove the plugs thin wall deep well 18mm 6 point socket @ $5.49 US. Also used a magnet to extract once loose.
Anyone have any idea why the previous owner would have capped off the throttle body connections to the stepper motor? Would this have caused the cold start issue? Since I've owned the bike I had to supply some throttle to start & until warm so that it would idle.
OEM pipes were corrugated plastic and would split causing problems. I would suggest reinstating with rubber vacuum pipe. However cold starting issues is also a classic symptom of valve clearances closing up. Some years back I had a 955 SprintST, developed rough cold start, all inlet valves had zero clearance, they'd supposedly been checked a couple months previous by the stealer.
Okay all the bolts are out and marked in the sequence the manual suggested the order of removal. Next the manual simply says remove the cover. It won't budge and I suspect it is soft magnesium so I haven't tried prying. Tips?
You’ll have to prise it up, there’s a rubber gasket which should have been fitted with silicone so will be stuck. I used a plastic pry bar when I did mine, like this:
As for these TB connections, as @Col_C says, the pipes probably split causing idling problems so have been removed. It might be that the previous owner has altered the fuel map to compensate but I’d be replacing them with either vacuum tube as suggested or thick wall silicone tubing as I’ve done. You just have to be careful with the routing to avoid kinks, especially when refitting the airbox.
Have you checked the coil packs and plugs sounds starting and running on two it may not be mechanical once you've eliminate then check valve clearance next and the cam timing
