HELP! MT07 died?? Hard start, loud noise and smoke from exhaust

[mjh937]

32 minutes ago, Timo023 said:

Nope  It has definately broken in half. Almost a perfect split.

Is it part #3?  That is supposed to be in two parts, unless I am misunderstanding your photos. 

[Timo023]

8 hours ago, mjh937 said:

Is it part #3?  That is supposed to be in two parts, unless I am misunderstanding your photos. 

Well yess then it might very well be dislocated.

[Triple Jim]

A friend of mine had a 427 Chevy that suffered major engine damage when a valve keeper came out like this.  He had just rebuilt it and apparently didn't quite get one of the 32 of them exactly into the groove on the valve stem.  One can only guess about why this one came out unless the previous owner knows and decides to share the information.

[Lone Wolf]

2 hours ago, Triple Jim said:

427 Chevy... He had just rebuilt it and apparently didn't quite get one of the 32 of them exactly into the groove on the valve stem.  

Yeah that was my impression when I first saw the photos.

For that theory, the prior owner would have had the cylinder head off the engine to compress the spring and access a valve. So that would be a question for the PO, did they ever have the head off the bike or do valve work. The new mechanic may be able to tell if it was a virgin engine, or if the head gasket etc. shows signs of having been replaced.

No one would need to go that deep into the engine for a simple valve adjustment (shims under the bucket).

If the valve adjustments were done on schedule, and the clearances were maintained without running exhaust valves too tight, the valves should last at least 100,000 miles without ever having to pull the head off a modern engine.

Edited January 20, 2021 by Lone Wolf

[Triple Jim]

5 minutes ago, Lone Wolf said:

Yeah that was my impression when I first saw the photos.

For that theory, the prior owner would have had the cylinder head off the engine to compress the spring and access a valve. So that would be a question for the PO, did they ever have the head off the bike or do valve work.

Another possibility is that the keeper was never really in the right place from the factory, but that's very unlikely.  It's a mystery unless the seller can tell Tim something about it.

Edited January 20, 2021 by Triple Jim

[Timo023]

On 1/20/2021 at 1:42 PM, Triple Jim said:

A friend of mine had a 427 Chevy that suffered major engine damage when a valve keeper came out like this.  He had just rebuilt it and apparently didn't quite get one of the 32 of them exactly into the groove on the valve stem.  One can only guess about why this one came out unless the previous owner knows and decides to share the information.

My mechanic didn't find anything else strange inside the engine. Luckilly, but also strangely. I have asked the previous owner about if he has done any valve work or whatsoever. But doub't if I will recieve a response.  I will also check the maintenance book kept by the first owner to see if I can find something there.

So in te end I am happy now that the fix is "only" 1200 euros and nothing else has been broken. However I am quite curious about the cause. Honestly I think misfit at the factory makes the most sense to me, how unlikely it might be. My mechanic did not see any signs that the cilinder head has been opened before. But I will await the response from the previous owner.

Or.... could there be something else be causing this and blowing my valve out, somewhere in my next three days?

[Triple Jim]

I don't think I understand.  Did the keeper come out, but the valve stayed in position and didn't fall in to the cylinder?  If so, what was the noise you heard?  Maybe it did fall in and you heard the valve hitting the piston, but then it's odd that no damage was done.

In any case I hope you have a properly running motorcycle soon!

Edited January 21, 2021 by Triple Jim

[AP996]

If the valve had dropped you would be looking for a new head and piston by now, lucky escape by the sound of it.

Edited January 21, 2021 by AP996

[Timo023]

12 hours ago, Triple Jim said:

I don't think I understand.  Did the keeper come out, but the valve stayed in position and didn't fall in to the cylinder?  If so, what was the noise you heard?  Maybe it did fall in and you heard the valve hitting the piston, but then it's odd that no damage was done.

Correct one keeper half was pushed up other half stayed in place. The valve stayed in place and also wasnt rocketed out because of the bucket going over the valve. So I was told by my mechanic.  So in that case I have indeed been lucky and have also been very happy that I did not drive it to the garage. Because that could have made it a lot worse.

The noise was because the valve was not properly functioning because of this and this caused the left engine to misfire. 

[Dennis.Halmstad]

One keeper in place probably was enough to hold the valve but it must have wedged the valve at a lower position making this valve not closing fully and creating the misfire. (lower position but not hitting the piston)

Bucket keeping the faulty keeper in there just enough that the correct keeper didnt release beacause then the valve would have dropped down and get hit by the piston with far more damaged parts.

Or am I thinking wrong here?

Your mechanic must make sure that the ridges on the valve and the keepers really are factory spec in case you shold reuse them.

 

You say youre lucky not driving to the garage, I say you are lucky overall because this could have become more worse even on your test starts in the garage.

Lesson: Compression test would have indicated on this.

[Triple Jim]

4 hours ago, Dennis.Halmstad said:

Lesson: Compression test would have indicated on this.

Yes, good point.

[Timo023]

7 hours ago, Dennis.Halmstad said:

Your mechanic must make sure that the ridges on the valve and the keepers really are factory spec in case you shold reuse them.

He will replace the valve and keeper just to be sure. 

Time to buy a compression tester.

 

[Lone Wolf]

Glad you have clarity on what the problem was - diagnosis can be so frustrating.

38 minutes ago, Timo023 said:

He will replace the valve and keeper just to be sure.  Time to buy a compression tester.

A good time to buy a compression tester would have been after my December 19 comment about how to use one.

At this point if you bought one you may never use it unless you work on older engines a lot.

I bought my compression tester over 40 years ago and it was helpful when all I could afford were old worn out cars and motorcycles. Your issue is very uncommon for a modern engine.

I would wait to buy a compression tester until you have a need for it again. Put that money into your repair.

[Timo023]

1 hour ago, Lone Wolf said:

I would wait to buy a compression tester until you have a need for it again. Put that money into your repair.

I have seen sets for just 30bucks.

I own a 1996 custom cb500 with 110.000kms on the clock. (15.000kms added evert year) I dont own a car but now I am about the be mobile again when the  Yamaha is fixed. I can put some more work on the Honda. Did quite some things so far but want to learn to do some engine work as well. So probably I will be needing it anyways somewhere in the future. But yess  I will have to wait a paycheck of two.  And yess I wish I had the tester earlier but even then it would have been stupid to try and fix it myself without any engine work experience.     

[Lone Wolf]

38 minutes ago, Timo023 said:

... for just 30bucks.

Gotcha. Here in America we have some parts stores that will loan out special tools if you purchase parts from them (just buy some fuel line or something). Compression testers, torque wrenches, valve spring compressors, etc.

One of my first jobs was at a lawnmower repair shop over 50 years ago, and it was a very simple introduction to the concepts of fuel, spark, and compression. Those lawnmower engines were so simple, no overhead cam. 

Some people don't enjoy getting their hands dirty and working on things, but it is like a Zen experience for me - and puts me in more control of what I am riding on. Or what I am cutting the grass with...

Edited January 22, 2021 by Lone Wolf

[Triple Jim]

2 hours ago, Lone Wolf said:

One of my first jobs was at a lawnmower repair shop over 50 years ago, and it was a very simple introduction to the concepts of fuel, spark, and compression. Those lawnmower engines were so simple, no overhead cam. 

Yes, small engines are great for learning.  In the 1960s when I was maybe six or eight years old my father got a box of parts from a friend of his.  It was a completely disassembled lawnmower engine that had overheated and scored the piston and cylinder.  Dad showed me how to put it together step-by-step, including marking and cutting gaskets from gasket stock, setting point gap, etc..  It wasn't going to run again, but I learned how an engine worked, and it wasn't long before I was working on engines that would run again.    

[shinyribs]

Wow. Did not see a (partially) dropped valve coming. Glad that you got it sorted, hate that you had to go the long way around. 

Not super uncommon for keepers to pop out when in the hands of a dude bro type. You know, the  rev bomber listen to my sick pipe on the rec limiter braaaDADADADADADADA type. 

[V8pel]

Hi guys and Girls , my sons MT07 2021 6000 miles suffered the same issue, I said to him if there is no fault light on it’s more likely a mechanical issue, 

first port of call , check for a spark , check for fuel , COMPRESSION CHECK ! 

He had the exact symptom two loud backfires , huge flame , loss of left hand cylinder 

checked the plugs , swapped the coil packs over , plenty of fuel/air ,lastly compression check , no compression on left cylinder 

removed engine from the frame , pulled the cams , cylinder one , left exhaust valve collet half popped out ?

not sure what caused it , I suspect over revving .

going to replace the collets with new ones 

 

[Triple Jim]

Interesting, V8pel.  Welcome to the board!

[longrider1951]

On 12/19/2020 at 6:03 PM, Timo023 said:

Thanks for you elaborate description. Yes both plugs looked like this. So the fuel map of the fuel commander is too rich. Once I have the bike running again I will see if I can alter the map a bit.

I will check some videos on how I can test if they are sparking properly. The plugs are new so this can be the problem. I switched the coils. No effect. So they aint the problem. Leaves me to check the electric signal to the coils somehow. 

But somehow I am starting to suspect a more mechanical issue here. Read an article about some guy with an mt09 who had his exhaust valves damaged which caused some similar problems. I will dig into this some more.

It sucks that the bike is broken but hey its a helloffa good way to get to know my bike hah.... Lucky its winter. 

 

I hear no mechanical noises that would cause you a problem. I work in a shop and a lot of times if you eliminate the power commander the problem goes away. I agree with most of the posters that your problem is electrical. If you have a friend with a similar bike eliminate the power commander and try using his ECU. That could be the problem.

[V8pel]

My sons 2021 07 has done it again , same valve 

i replaced the valve , spring ,cap,retainers ,correct valve clearance , done a fair few miles since the last time , pretty sure the issue is with the quick shifter and aftermarket exhaust, I believe its the accumulation of unburnt fuel and free flowing exhaust that caused the issue, the duration on the shifter is obviously too long , same massive backfire and then miss firing.

i have recommended he gets it mapped properly and set the duration a bit shorter on the shifter 

 

fingers crossed 🫣