what's wrong?

mb460

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Joined
Apr 22, 2013
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7
sitting at a light,

turned green..

hit the gas,

loud clunking sound

pulled the spark plugs and one cylinder was bent in. (don't know which one, i'm not the one that pulled it. i'll get that info)

what could it be?

the piston is in tact, the bike still runs, the piston rod is in tact, it's not a "chunka chunka chunka" sound like a piston is slamming back n forth inside the cylinder, and all three cylinders have heat coming from the pipes measuring the same temp on all three as if it is working correctly, but there's definitely a tinging noise. all 3 cylinders have compression too

i'm NOT a triumph mechanic, i have no freakin clue how to work on these, i work on japanese sport and vintage bikes, but i was tasked with..... no...... i was begged to take this project on. i'm thinking it will be easier to replace the motor than to dig into it, and a hella lot cheaper, but the insurance adjuster told me i need to tear it apart. (Cluster FFFF)

Knowing literally nothing about this bike, i figured i'd ask around a little bit and get SOME sort of an idea what i'm looking for before i tear into it.

i'll tell you what I think it is later, but i want to hear your opinions (about the bike) first.

and if anyone has a downloadable manual (i haven't searched one out yet) please link me.. thanks!!
 
Given this is a rocket 3 forum, i kinda expected it would be obvious that it was a rocket 3. sorry.. as for specific types of rocket 3? no idea..... it looks exactly like the one in the logo.


and.. i definitely see the confusion on the other question.

the spark plug (from) one of the cylinders was bent in. i.e. no gap.. was pounded in by the ....... piston? valves? something, i don't know the configuration of this motor to know what could hit it. that's why i'm asking these things.

the cylinder wasn't bent in.
 
bent cylinder

You still have not provided enough details
Now you are saying the spark plug electrode is bent and not the cylinder? Or you mean the piston?
I would think the if the piston was bent it would not even turn over.
If the spark plug is bent then try changing them to new ones.
Perhaps plugs are the wrong size and too long, therefor getting hit by the top of the piston? Bad!

Or you have a broken connecting rod? Bad too!
More details needed.
 
I love when people say they can't work on this bike because it's a Triumph. It's a double overhead cam, 4 valve per cylinter internal combustion engine just like any Japanese sport bike engine, only bigger and turned sideways.

Can you turn the motor over with the plug wires off and see if you can hear the location of the noise? If it's something making contact, it still should make contact with the motor just turning over.

My initial guess would be timing chain guide, but you say the bike is running fine except for the 'tinging' noise...

I don't know what could bend the spark plug, unless it was bent when it was put in? Were both spark plugs bent? There are 2 plugs per cylinder. The Rocket has a really low compression ratio of 8.5 -1 so the piston is a considerable distance from the spark plug.

And you said insurance adjuster? Was this bike in a wreck?
 
So you work on Japanese and vintage bikes, well the Rocket engine is much like any other engine but turned at 90°?????

You've got the same heat coming from all the pipes, compression on all cylinders, that's with a bent plug electrode?????

:confused::confused::confused::confused::confused:

Edit:

Beat me to it Tx. :p
 
I love when people say they can't work on this bike because it's a Triumph. It's a double overhead cam, 4 valve per cylinter internal combustion engine just like any Japanese sport bike engine, only bigger and turned sideways.

Can you turn the motor over with the plug wires off and see if you can hear the location of the noise? If it's something making contact, it still should make contact with the motor just turning over.

My initial guess would be timing chain guide, but you say the bike is running fine except for the 'tinging' noise...

I don't know what could bend the spark plug, unless it was bent when it was put in? Were both spark plugs bent? There are 2 plugs per cylinder. The Rocket has a really low compression ratio of 8.5 -1 so the piston is a considerable distance from the spark plug.

And you said insurance adjuster? Was this bike in a wreck?

as for insurance, he called the insurance company, and they told him to bring it to a shop and get a quote, it wasn't in a wreck, but apparently he did drop it in the grass at some point while it was running.

as for pulling the plugs, i just did that and cranked the motor over, but the starter noise masks anything i may hear, and doesn't spin the motor over fast enough to make the tinging sound i don't think. but yeah, the low compression does make sense that it wouldn't be the piston hitting the plug.. let me call the guy to figure out which plug it was, i do know that he had the valve cover off, and various other things, i really need to get more info at this point. but... he's not really mechanically inclined, and just started taking bolts out. he did say that he didn't find anything worth noting when he did.

i don't know how i get myself into stuff like this haha..

i was really hoping someone would have an obvious answer. what i thought it may be was a spun crankshaft bearing which could in theory add extra clearance for the piston to top out.

and yeah i do realize now that there are 2 plugs, he said "plug" singular, so... yeah, its confusing the crap out of me too. i'll get back to you in a minute.
 
ok, he says he "thinks" it was the second plug in the back cylinder (#1)

i wonder if it's just low on oil or some stupid crap like that..................................................................... that would cause lifters to knock n crap... i'm going to check that. i asked him before if it had oil in it, he said yes, so i haven't thought to verify it.
 
ok, the sound is coming from the back cylinder as well, and yes, there is oil in it according to the dip stick.

:-/ still at a loss here
 
Quoted..but... he's not really mechanically inclined,

Do NOT have someone that is " not mechanically inclined " work on your bike.
Seriously....
 
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