Intake valves? Need diagnosis - video/audio provided

[hotshot38]

2005 GZ250 7500 miles (bought it with 4500 miles)
So, I was driving down the highway to work a couple of days ago...about 70mph for 5 mins, gave it a bit more throttle to get around a car and all of a sudden I lost power. No significant sound, just like it ran out of gas, but without all the sputtering. I was able to glide to the side of the highway and wait for AAA.

Here's the video of the 'clicking' sound it makes when I turn it over.
https://youtu.be/CuLOXtSde-k

A video of the moment it broke down: https://youtu.be/nyJn7Gf0wmY

I used a stethoscope to determine the sound is most prominent near the intake valves. I removed the cover and they are still moving up and down while cranking.

Recent work:
Valve adjustment 500 miles ago. - ran fine, lots more power
Carb Clean 100 miles ago - starts awesome....no more 10 minute choke sessions
Changed air cleaner
Changed oil 50 miles ago (yes, there is oil up near the intake valves when I took the cover off)
Bike ran PERFECT for the last 100 miles since the carb cleaned. Golden pipes and nice color on the spark plug.

Steps taken:
- yes, gas going to float bowl
- yes, spark

Any help appreciated on the cost and complication of doing a valve job or worse.

Thanks,
Sean
- mechanically competent, but not a mechanic, and certainly don't have the tools for an engine rebuild.
(Also, I own a 1988 Goldwing GL1500/6) but the GZ is more fun to drive!

[blaine]

Sounds like little to no compression.I'm thinking bent or broken valve. :(

[spldart]

Well. Poop!
I'm continuing to lose compression on mine slowly but surely.
I'm starting to think these little 250's should never be on the highway.
Valves adjusted, fresh oil and everything.

Start with compression test.
If low/none check for at least some valve/rocker clearance at no lift.
If you have clearance at no lift intake and exhaust but no/little compression then it's time to
dismantle motor.

I'm thinking my motor is heading where your's is right now :(

[spldart]

Actually. It does sound like a valve train problem while cranking doesn't it?

Still. An autopsy is needed.

Sounds like little to no compression.I'm thinking bent or broken valve. :(

[hotshot38]

Thanks guys. Now that the weekend is here I'll investigate further. I just got my motorcycle lift put together. Was going to use it to change the speedo gears on the Goldwing, but now I get a chance to practice using it on the lighter bike first. Hmmmm...now where did I put those tiedowns.

[Water Warrior 2]

Just be thankfull you were in little to no traffic when the bike quit. That could have been a real game changer for a safe stop.

In the video the starter sure whirls it over fast enough to catch. Just a different idea..............did you check for spark at the plug yet?? An ignition part may be a lot easier than an engine teardown.

[hotshot38]

Yes, definitely spark. In fact, I believe I still had the spark plug out when I recorded the video. Although, it turned over just as easy/fast whether the plug was in and out.

I work an early shift and live in the opposite direction that the main traffic. On purpose; I hate traffic. This was 635am and as you can see, the traffic coming the other way was a bit heavier. And of course, I could have pulled to the left shoulder, although not as comfy or safe there.

Here's a vid of AAA picking me up: https://youtu.be/g5NLSX731K0
I appreciated that they brought a trailer. Last time I needed a bike towed back in the 80's, they picked it up with the hook. Something I wouldn't want them to do with my Goldwing.

[WJTED1]

Hello...this is EXACTLEY..what happened to mine 8 days agao..but I heard a pop sound..it makes the same clicking sound now as does yours. 2 weeks previous to this mine was sending out some white smoke at start up. I have posted on this also and just need to find the time to take the engine out. Cyclepedia has a great step by step to pull the engine. It's a subscription. Good luck!

[hotshot38]

Thanks for that WJTED1. I haven't had a chance to look at it since it rained most of the weekend. I'm trying to figure out whether it's worth fixing or not. I haven't lapped a valve in probably 30 yrs.
:(

[WJTED1]

I don't know how long the threads stay open but I will update this thread when I get the engine off. I want to learn what happened but I am like you..it might not be worth it to fix it.


Sent from my iPad using Tapatalk

[hotshot38]

...in more ways than one.

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=278

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=278

I don't think this intake valve spring is supposed to be hitting this cover :doh:

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=279

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=279

[spldart]

Doh!!!

The more I look at this the more I wonder how the spring retaining hardware struck the top of the head like
that.
Did the valve shaft break?
Spring retainer fail? Keepers fail?

Were you turning insane rpm? This looks like a valve float kinda failure...

Oh... And you may not be to hosed.
Remove your engine head.
Examine piston top. Don't remove cylinder.
Is piston damaged around where that valve was position?
Not just a spot where the carbon got knocked off but is it cracked or chipped or broken.
If yes then maybe motor is impractical repair.
If no then.
Get donor engine head. Steal a valve, spring and retaining hardware. Slip the donor valve in old head and
using lapping tool and some compound for a bit.... Assuming the valve fits in guide properly. Lap the crap
out of it.... Look up this on youtube... Then install donor hardware and remount head as per service manual
with new gasket...

Possible joy for cheap.
I've done it. Cracked valved on old motor. Fixed for about 50 bux and it ran a good while.

[hotshot38]

Yeah...the spring is definitely out of place. I can compress it slightly with my finger. AND, the clicking sound does not correspond with the spring/retainer hitting the wall.

Now, as for the cause of all this....that is going to be for a day when I have more energy. Gonna consult with some local motorcycle buddies :ride: and maybe they'll volunteer to fix it. *fingers crossed*

[spldart]

AND, the clicking sound does not correspond with the spring/retainer hitting the wall.

Ok... That definitely sounds like piston head and valve are smacking around a bit.

[WJTED1]

I thought I lost my video of the breakdown but I have it. Do I have to post through YouTube?

[hotshot38]

I posted to youtube and just posted the link here. Not sure if you can post/upload videos to this old vB forums

[hotshot38]

This thread may give more insight
Dropping Valves
http://www.gz250bike.com/forum/showthread.php?t=6215

I'm going to try to get the head off tonight

[hotshot38]

When I took the cover off the spring basically could be pulled off by hand. The 'keepers' looked damaged...at least one half moon did. Sorry, no picture.
The valve itself is definitely lower than the other valves and will not budge using hand pressure.
Clicking noise is still there when I turn it over so I suspect it is kissing the piston.

1.
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=280

2.
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=281

3.
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=283

4.
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=284

5.
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=285

6. Exhaust valves
http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=286

:coffee:

[spldart]

:sad face:
It looks like the stem of the valve is intact and your keepers got out due to valve float from
over revving.
Considering how low that 'stem' is in the photo there is no doubt the valve has contacted
the piston.
I'm anxious to see what the piston and the rest of that valve look like.
Thanks for the pictures.

[hotshot38]

Here is the piston:

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=287

And here is the valves

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=288

And here is the extracted valve which I bent with my mind, Kreskin style :lmao:

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=289

I think I am thru with GZ250's. This will soon be on Craigslist as a basketcase.

[spldart]

:doh:
Even though you don't have a hole in the piston that is still unsafe territory for
rebuild.

Needs:
New piston
New rings
A new gasket
New single valve
New keepers "just to be sure"
New spring "just to be sure"

Fresh hone on cylinder
The labor on the top end job in general

Me?! I'm still researching chinese alternative for engine parts for gz owners. Just emailed someone on a cyl bor kit tonight :)
My malady is low compression. Still running but yeah.

[spldart]

Thanks again for sharing all the pictures. We all learn from this stuff all forensic like :)
:tup:

[hotshot38]

The Spring looks ok...but the valve guide is pooched also

http://www.gz250bike.com/forum/picture.php?albumid=47&pictureid=290

[spldart]

I let my fav old machine shop press in valve guides. So ... yeah...
That's another tab on the bill.

I'm thinking your right... This is a boneyard situation :(

[spldart]

I'm still staring at that valve seat....
It doesn't look like the valve was striking it properly for a while before engine failure.....
I dunno..
Just saying..