Engine trouble after krasch

[Mike_swe]

I had i little slow speed krasch, and after that something is wrong. It landed on the left side, valve cover scratched (had to seal two small holes) other than this just minor cosmetic damage.

Now to the problem:

The engine starts and idles well, and also runs fine at low speed. But as soon as I open the throttle more than about 1/3 it starts to judder. It doesn't look like it has anything to do with engine speed or load, only the throttle opening. Can't see any damage on the TPS, but the spark plug connector/coil is scratched.

 

[Fanum]

OK, who's gonna win the race to post the two pics first???

 

[Tobers]

Most likely the coil has come off the spark plug. Check both plugs on the side you crashed on and make sure the coils are properly seated. You'll need to remove the plastic covers to do this - quick to do though.

I had the same thing - smooth running at low throttle opening - horrible once you open it up a bit.

The cause is one plug not firing so lots of unburnt fuel and misfiring.

 

[Mike_swe]

Most likely the coil has come off the spark plug. Check both plugs on the side you crashed on and make sure the coils are properly seated. You'll need to remove the plastic covers to do this - quick to do though.

I had the same thing - smooth running at low throttle opening - horrible once you open it up a bit.

The cause is one plug not firing so lots of unburnt fuel and misfiring.

I have only checked the connector on the upper plug because that was the one that was damaged. I will check the lower one tomorrow.

How does it work? Is it the lower one that comes on with higher load/throttle opening and the upper is always on? Or is it the other way around?

 

[Mike_swe]

I found this thread:

http://www.ukgser.com/forums/showthread.php?s=&threadid=39465


I'm pretty shure now that the lower coil must have popped out. Even if it didn't touch the ground the impact must have caused it. The coils are quite heavy.

 

[GSmonkey]

Mike, this happened to me. When I the bike went down heavily on the left, it was enough to pop out the secondary spark plug coil.

Symptoms just like yours, hesitation on full throttle.

 

[Mike_swe]

I give up . I have checked that all four coils are correctly seated, and the problem remains. I have checked the sparkplugs also for deposits but they look ok. The bike is going to the workshop next week anyway for check of other damage, I hope they will find what is wrong.

 

[Fanum]

Have you checked these;

(top pic throttle cable seated badly in body bracket)

Just wondering if the tank might have moved in the impact and dislodged a vable on one/both sides??

Sounds like similar symptoms

 

[Mike_swe]

Have you checked these;

(top pic throttle cable seated badly in body bracket)

Just wondering if the tank might have moved in the impact and dislodged a vable on one/both sides??

Sounds like similar symptoms

No. But I will do. Thanks for the tip.


Just thought of another thing. I had the side panels and tank removed to check underneath, couldn't see anything wrong so I put it back on. When I did this I had the battery disconnected. Then I forgot that when it is connected again, you should open the throttle fully and close it a couple of times to "learn" the TPS sensor. Maybe that is the problem.

 

[Fanum]

Yes, but only after taking fuse 5 out.

then ign. on, twist twice, ign off, replace fuse.

 

[Mike_swe]

Yes, but only after taking fuse 5 out.

then ign. on, twist twice, ign off, replace fuse.

Fuse 5? The owners manual says to turn the ignition on and then turn the throttle twice, after the battery has been disconnected.

 

[Mike_swe]

The throttle cables were OK.
I disconnected, and connected the battery again, turned the ignition on, twisted the throttle grip fully open twice, and started it up. The idle speed was higher than before, ~1500rpm. When I starded it this morning it was ~1000rpm. I will have a go tomorrow and see if it's cured now.

 

[GSmonkey]

...taking fuse 5

...1200GS....fuses....wot you on about geeza???

 

[Mike_swe]

He was trying to confuse me.

 

[gb's]

I had a similar low speed accident and post accident symptoms. Problem finally tracked down to a very small crack in the bottom spark plug. Changed the plug and everything back to normal.

 

[Fanum]

...1200GS....fuses....wot you on about geeza???

Doh!!

Missed that it was a 12........


Disconnecting the battery is obviously the same as removing fuse 5...you could do either if it were an 1150.

 

[Mike_swe]

Took it out today to check it. As soon as I was out on an open road I did a full throttle acceleration i 4:th gear, a couple of misfires but not nearly as bad as before. Did it again in 4, 5, 6:th gear and the misfires gradually dissapeared and now it appears to be running normal again

The fault was most likely a loose spark coil on the bottom right side. Then when I fixed that, I forgot to reset the TPS sensor which caused similar symptoms.

 

[Mike_swe]

Solved!

After checking all the coils and found bottom right one loose, I still had a lot of misfiring at acceleration. Checked all sparkplugs and found two tiny cracks in the top left plug (the side that hit the ground), replaced that one and now the engine runs perfect again.

 

[ktmmark]

Glad it was simple in the end