Bandit Alley
GENERAL MOTORCYCLE FORUMS => GENERAL MECHANICAL & TECHNICAL => Topic started by: solman on January 04, 2008, 03:31:05 AM
-
One of the guys I know with a Bandit 1200 with 1900 miles on it. I assisted him in adjusting the valves. He never did his initial valve clearance check. We took our time and adjusted the valves to spec. When it was all said and done, he started the motor and it ran great for about 15-20 sec and then CLUNK! It just seized up and we can turn it a little back and forth, but that is about it. We took the cover back off and look in the head and found nothing wrong in the top end. Only thing I can thing of that didn't go as planned is when he rotated his motor backwards a little bit. Any ideas because I am utterly stumped and really need some ideas!
-
Sorry to hear about the troubles.... some more information might help point you in the right direction.
With the spark plugs loosened, can you rotate the motor 360 degrees with a wrench via the sig gen nut??
Are both dowel pins in place as opposed to wedged somewhere?
Have all tools been accounted for??
To start fine is a good sign.... might check the kill switch too. Just grasping for straws here.
-
What TX said. Yep, it sounds like a classic case of something got dropped inside. An alignment pin perhaps. If you can't see it around the cam area then it may have been small enough to go down an oil way, maybe jamming in the cam chain on the lower end. If this is the case...well, I don't even wanna think about that.
-
We took the valve cover off and accounted for everything. I was looking at the manual and I am wondering if it might have something to do with the starter clutch. My first thought about something missing and falling was my first thought as well. But all the parts and tools were all accounted for. I am stumped on this one for the most part. I have been doing valves on bikes including my Bandit for years. I have never came across something like this before. Only possibility that I can think of at this point at one point when he turned it backwards, it screwed something up. I haven't torn a Bandit motor down yet, so I can't get a visual picture of what the inside looks like. BTW, is the cam chain tensioner automatic on Bandits? I know that on my Honda, I loosen the nut and it then adjusts itself. Is the Bandit something like this?
-
One of the guys I know with a Bandit 1200 with 1900 miles on it. I assisted him in adjusting the valves. He never did his initial valve clearance check. We took our time and adjusted the valves to spec. When it was all said and done, he started the motor and it ran great for about 15-20 sec and then CLUNK! It just seized up and we can turn it a little back and forth, but that is about it. We took the cover back off and look in the head and found nothing wrong in the top end. Only thing I can thing of that didn't go as planned is when he rotated his motor backwards a little bit. Any ideas because I am utterly stumped and really need some ideas!
Holly Kry'kee! I thought this stuff only happened to me! The drive gear for the starter, nut back off ?
-
Well, we checked the starter and a few other things and came up with nothing. He is going to try and take it in tomorrow to get it done using the warranty.
-
Oh boy, mums the word. That is why I learned long ago that the only mechanic work or supervision I provide is to wife and mother who cant give me the evil eye when bad things happen to good engines through no fault of my own. Even until this day I rotate and check my valve adjustments 6 times and 6 rotations as I was taught and it has saved my hiney more then once, not that it happened in your case but even the experienced human mind can miss an obvious mistake.
He is going to try and take it in tomorrow to get it done using the warranty.
-
Well, we checked the starter and a few other things and came up with nothing. He is going to try and take it in tomorrow to get it done using the warranty.
Ok good luck on the Warr. Maybe U need to edit or make this post go away! Dealer and warr! :annoy:
-
Although I don't know what the TDC squish clearance on a B1200 engine, I read that with the combination carbon build up and close squish clearance on modern engines, it is very possible to have a catastropic failure if valve clearance is set too loose. Especially as the engine warms up and higher RPMs diminish the already close clearance to almost zero and the extra loosened valve clearance allows it to be held open on its seat when it should be closed, resulting in a collision with the piston followed by a crank, cylinder and crankcase train wreck.
-
I think you mean if it is set too tight.
-
I think you mean if it is set too tight.
+1.... too tight is major bad.
-
NO, if the valve clearance is too small the valves will leak and hot gases will burn the exhaust valves, fixable. If the valve clearance is too large, the necessary gentle opening and final closing contours of the cam lobe will become ineffective resulting in violent impacts taking their place. The resulting pounding quickly becomes a failure as the loosened seat holds the valve open when it should be closed and the piston hits and broken in the process, not so fixable especially when the crank & cylinder get involved. But hey its rare OK?
-
Wow. That just doesn't jibe with me CWO. I have to go with the other guys and say if you have a loose (ie. bigger gap) at the adjustment, then, with the help of the spring, the valve is going to open less. Thus, less chance of anything hitting it. Of course, I am dyslexic so there is a small chance I am thinking backwards. :shock:
-
Gunner are you refering to it being "too small" as the clearance from the tappet to the valve? if so that would mean the clearance is too tight meaning not enough for the valve to close properly andit would open to far for too long which would not be good. Or did I misunderstand??
-
The resulting pounding quickly becomes a failure as the loosened seat holds the valve open ...
Would you by chance be referring to the valve guide instead of the valve seat??
-
No, valve guides leak and allow burning of oil. Anyway as Bogart would say, lets just skip it.
The resulting pounding quickly becomes a failure as the loosened seat holds the valve open ...
Would you by chance be referring to the valve guide instead of the valve seat??
-
No, valve guides leak and allow burning of oil. Anyway as Bogart would say, lets just skip it.
Just trying to learn something..... :shrug:
-
Man we can make a bad situation worse some times can't we! remember he said the eng ran fine for a few seconds? So valve clearance must have been ok, and now he said all looked good when it was opened up to check! But how do you know the set is ok when it can't be rotated? Are you sure the dowels are where they are supposed to be? This could stop an eng @ Idle and lock it if it found the bottom of the chain and crank sprocket.
-
1900 or 19000 miles? Why were you adjusting them? Did he hear a noise to want this done? Where is Red 01 he knows! :bigok:
-
1900 or 19000 miles? Why were you adjusting them? Did he hear a noise to want this done? Where is Red 01 he knows! :bigok:
Not adjusting the valves will eventually lead to burnt valves. I know that because of a 900 I bought before and ended up with a burnt valve because they were never adjusted.
There are two dowels and all the hardware was accounted for.
-
One of the guys I know with a Bandit 1200 with 1900 miles on it. I assisted him in adjusting the valves. He never did his initial valve clearance check. We took our time and adjusted the valves to spec. When it was all said and done, he started the motor and it ran great for about 15-20 sec and then CLUNK! It just seized up and we can turn it a little back and forth, but that is about it. We took the cover back off and look in the head and found nothing wrong in the top end. Only thing I can thing of that didn't go as planned is when he rotated his motor backwards a little bit. Any ideas because I am utterly stumped and really need some ideas!
This is also on another board and to recommended he bring the bike to me. I am only about 4 hours from you. Sorry to hear about the delema and you have my number 760-314-7042
-
Same person, he is not a member of this forum.
-
We weren't able to find a definite cause. It seems that it may have jumped a tooth and threw the timing off. Damage was valves and a cracked piston. The original quote was $1700 to fix it, but they were able to negotiate with Suzuki and got it down to $300. It sucks, but at least it is now affordable and will have it back in the later part of the week.
-
We weren't able to find a definite cause. It seems that it may have jumped a tooth and threw the timing off. Damage was valves and a cracked piston. The original quote was $1700 to fix it, but they were able to negotiate with Suzuki and got it down to $300. It sucks, but at least it is now affordable and will have it back in the later part of the week.
Usually on a bike with low mileage, when this happens, it is usually a bad cam chain adjuster. I would wager to say it failed and was not adjusting properly. Also I do not believe that one tooth off is enough to cause piston to valve mating. I am wondering if a valve keeper let go? Maybe a bad or weak valve spring. I have had a keeper let go before.
Glad you go it down, because $1700.00 is way high price. For that price or very close to it I could have installed a set of JE Standard bore 11 to 1 forged pistons and had the head fixed with a valve job.
-
I am sure if I would've tore into it myself, I would've found the culprit. They did say that the timing was off, but I don't know by how much. I personally don't trust stealer's mechanics too much. I'lve seen too much shady stuff come out over the years.
-
I am sure if I would've tore into it myself, I would've found the culprit. They did say that the timing was off, but I don't know by how much. I personally don't trust stealer's mechanics too much. I'lve seen too much shady stuff come out over the years.
Proably, I wish I could have see it. But hopefully they will do a good job, but my money is betting they won't.
-
At least it will then fully fall on them.
-
At least it will then fully fall on them.
Maybe, but then I don't put to much in to dealers!
-
Neither do I. My Bandit have been to them once. It was for my initial valve check to put me into the system.
-
We weren't able to find a definite cause. It seems that it may have jumped a tooth and threw the timing off. Damage was valves and a cracked piston. The original quote was $1700 to fix it, but they were able to negotiate with Suzuki and got it down to $300. It sucks, but at least it is now affordable and will have it back in the later part of the week.
Glad you got it resolved. Weird!
Jim
-
Something funny happened. They got all the new parts installed and started it up. It did the same exact same thing again. Here they are trying to blame us and they have it do the same thing after they (supposed qualified mechanics) worked on it. Something odd is definitely going on with that motor.
-
In a weird way.... that's good news. Keep us posted please...
-
Sounds like it needs to have the clutch pulled to isolate whether it is the egine part or something in the transmission area.
-
it is apparently the engine part. The timing was off again. It seems that it is jumping a tooth and causing damage. It sucks because of the time lot, but good in the sense that it is backing him up that something is definitely wrong with the motor.
-
it is apparently the engine part. The timing was off again. It seems that it is jumping a tooth and causing damage. It sucks because of the time lot, but good in the sense that it is backing him up that something is definitely wrong with the motor.
Wow, I am wondering if the crank gear is bad? The crank sprocket is an integraded part of the crankshaft. But with out seeing the engine, I could not tell you for certain.
Reasons for it chain jumping:
bad cam chain tensioner
bad or missing cam chain guides (must be real bad)
bad or broken gears
worn out cam chain
-
They said that they looked at the bottom end after it happened the second time and couldn't find a problem. My educated guess seems to head in the direction of a bad cam chain tensioner. This especially comes to mind considering the low mileage of 1900 miles.
-
They said that they looked at the bottom end after it happened the second time and couldn't find a problem. My educated guess seems to head in the direction of a bad cam chain tensioner. This especially comes to mind considering the low mileage of 1900 miles.
With out seeing though, your guess is as good as anyones.
-
Apparently the problem was the metal piece inside the spark plug boot fell out and then inside the motor. I believe that it was million to one chance of something like happening. It apparently got wedged in one of the cam chain teeth and got stuck there causing it to jump a tooth.
-
Apparently the problem was the metal piece inside the spark plug boot fell out and then inside the motor. I believe that it was million to one chance of something like happening. It apparently got wedged in one of the cam chain teeth and got stuck there causing it to jump a tooth.
Not saying that can happen, but sure sounds hard to swallow to me. Especially the way the spark plug boots are made. Were the coils removed when the valves were adjusted? I always remove them just so I have more room to work and to get he valve cover out. They never go back in until after the valve cover is back on and the plugs are installed.
-
I personally don't ever remove the coils to do a valve job. I didn't do the work, so all I got to go on is what he tells me.
-
I always remove the spark plug boots then blow out or inspect the wells to insure no debris before removing the spark plugs (dirt bike habit) to remove the cover. I have heard of the electrode breaking off, even the porcelain insulators, but I have never heard of a boot falling inside the engine through the spark plug hole. But I suppose there is a first time for everything.
-
I always remove the spark plug boots then blow out or inspect the wells to insure no debris before removing the spark plugs (dirt bike habit) to remove the cover. I have heard of the electrode breaking off, even the porcelain insulators, but I have never heard of a boot falling inside the engine through the spark plug hole. But I suppose there is a first time for everything.
It didn't fall in the sparkplug hole, the valve cover was off for a valve adjustment.