2006 ZS250GS

m0t0 · 04-01-2013, 12:09 PM

Hello Everyone!! I'm fairly new to the forums and am hoping i can get some wisdom. I picked up a 2006 zs250gs a few months back. It has just over 2000 miles on it. I cannot get it to start for the life of me. (common problem right!) I can tell you that i have spark, it seems week to me but it is there. It will shock me if its not grounded, but its not like some lawn mowers that will make your teeth chatter. I'm guessing the bike had been sitting before i got it. I tore down and cleaned the carb. I also drained and dried the tank. I seem to have good compression. I cover the spark plug hole with my thumb and my thumb will be blown off when i crank it over, but i can also press hard and my thumb will not come off. I also dont seem to have any air moving out the exhaust when i crank it over. I have tried charged the battery that was on it, and have tried a known good battery from another bike with no change. One other strange thing the battery light is always on. Normal or not? Any thoughts? Thanks in advance.

m0t0

Weldangrind · 04-01-2013, 02:43 PM

It sounds like you have a compression problem, because you should not be able to hold your thumb over the hole. My guess is that one or both of the valves are too tight.

FastDoc · 04-01-2013, 03:04 PM

I agree with Weld.

Indeed this looks like Page 1 out of my book of adventures with the same bike.

Before you move on adjust the valves and check the compression with a gauge.

If you have a compression issue it's not worth pursuing other issues until that's resolved.

I spent about $150 on a new stator, coil, and pickup and CDI for mine before I discovered the problem was compression.

m0t0 · 04-01-2013, 06:51 PM

Thanks for the replies. I will pick up a compression tool tonight and let you know. What is entailed in adjusting the valves? I vaguely remember seeing that i have to pull the motor to accomplish this?

Also, what should the compression read at?

Thanks Again

FastDoc · 04-01-2013, 07:23 PM

For the valves check out Spudr Rider's excellent tutorial. This will directly apply to your bike.

I would estimate normal compression for your bike to be about 160-175. Anything above 150 is probably fine. Anything under 100-125 could keep it from starting.

m0t0 · 04-01-2013, 08:23 PM

Is this the article your referring to?

http://chinariders.net/modules.php?n...ewtopic&t=6458

FastDoc · 04-01-2013, 09:27 PM

That's it. The process should be identical to your bike.

m0t0 · 04-02-2013, 11:28 AM

Well it looks like you two nailed it on the head. I picked up a compression tester from HF. When i tested it the highest reading i got was approx 32 psi. I will work on getting the valves adjusted. Do you by chance know what the clearance should be at for this bike?

Thanks,
m0t0

FastDoc · 04-02-2013, 12:17 PM

The head should be identical or very nearly so to the 200cc model so I would go with whatever numbers Spud used in his post.

I hope it is just a tight valve.

FastDoc · 04-02-2013, 12:17 PM

BTW did you check the compression with the throttle wide open and the choke off (open)?

m0t0 · 04-02-2013, 03:03 PM

Quote:

Originally Posted by FastDoc

BTW did you check the compression with the throttle wide open and the choke off (open)?

Yep throttle wide open and no choke on.

FastDoc · 04-02-2013, 04:11 PM

Well, you did it right... :wink:

m0t0 · 04-03-2013, 11:21 AM

I feel a bit defeated at this point. But, "Never give up, Never surrender!"

I adjusted the valves according to the post i linked above and re-tested the compression. There was an improvement, but not much of one. I'm now getting roughly 40 psi instead of 35 psi. Any recommendations on where to look next?

Thanks,
M0t0

FastDoc · 04-03-2013, 11:58 AM

A compression problem such as this can only come from the piston/cylinder or the head. Possible culprits include piston or ring damage, valve seating problems or perhaps a crack in the head.

Next step is to put about 5-10cc of oil in through the spark plug hole and recheck compression. If it comes up a lot, say to 150 or so, the problem is likely the piston/cylinder/ring interface. If it does not come up a lot the problem is the valves and head.

The step after that is you have to remove the engine

. It is not possible to remove the head with the motor in place with this model. I know this from experiance.

We have seen similar issues with this model a number of times. We do not know why this normally robust engine design gives such problems, but it does.

I would debate selling it as is, this is what I did with mine. :?

It is fixable, but I threw in the towel with mine.

I think these engines develop problems early, so I figured if I fixed mine with original parts it would just puke again. :x

I only paid like $150 for mine so it did not hurt my feelings to see it go.

m0t0 · 04-03-2013, 01:27 PM

Thanks Doc I appreciate the reply. Ill give the oil test a try tonight. I totally hear where your coming from on moving on, but this bike is actually for my wife to learn on, and she has grown attached to it so it looks like ill be in it for the long haul. :roll:

04-01-2013, 12:09 PM	#1
m0t0 Join Date: Feb 2013 Posts: 32	2006 ZS250GS Hello Everyone!! I'm fairly new to the forums and am hoping i can get some wisdom. I picked up a 2006 zs250gs a few months back. It has just over 2000 miles on it. I cannot get it to start for the life of me. (common problem right!) I can tell you that i have spark, it seems week to me but it is there. It will shock me if its not grounded, but its not like some lawn mowers that will make your teeth chatter. I'm guessing the bike had been sitting before i got it. I tore down and cleaned the carb. I also drained and dried the tank. I seem to have good compression. I cover the spark plug hole with my thumb and my thumb will be blown off when i crank it over, but i can also press hard and my thumb will not come off. I also dont seem to have any air moving out the exhaust when i crank it over. I have tried charged the battery that was on it, and have tried a known good battery from another bike with no change. One other strange thing the battery light is always on. Normal or not? Any thoughts? Thanks in advance. m0t0
	0

04-01-2013, 02:43 PM	#2
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	It sounds like you have a compression problem, because you should not be able to hold your thumb over the hole. My guess is that one or both of the valves are too tight. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

04-01-2013, 03:04 PM	#3
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I agree with Weld. Indeed this looks like Page 1 out of my book of adventures with the same bike. Before you move on adjust the valves and check the compression with a gauge. If you have a compression issue it's not worth pursuing other issues until that's resolved. I spent about $150 on a new stator, coil, and pickup and CDI for mine before I discovered the problem was compression. __________________ Happy to serve.
	0

04-01-2013, 07:23 PM	#5
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	For the valves check out Spudr Rider's excellent tutorial. This will directly apply to your bike. I would estimate normal compression for your bike to be about 160-175. Anything above 150 is probably fine. Anything under 100-125 could keep it from starting. __________________ Happy to serve.
	0

04-01-2013, 09:27 PM	#7
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	That's it. The process should be identical to your bike. __________________ Happy to serve.
	0

04-01-2013, 06:51 PM	#4
m0t0 Join Date: Feb 2013 Posts: 32	Thanks for the replies. I will pick up a compression tool tonight and let you know. What is entailed in adjusting the valves? I vaguely remember seeing that i have to pull the motor to accomplish this? Also, what should the compression read at? Thanks Again
	0

04-01-2013, 08:23 PM	#6
m0t0 Join Date: Feb 2013 Posts: 32	Is this the article your referring to? http://chinariders.net/modules.php?n...ewtopic&t=6458
	0

04-02-2013, 11:28 AM	#8
m0t0 Join Date: Feb 2013 Posts: 32	Well it looks like you two nailed it on the head. I picked up a compression tester from HF. When i tested it the highest reading i got was approx 32 psi. I will work on getting the valves adjusted. Do you by chance know what the clearance should be at for this bike? Thanks, m0t0
	0

04-02-2013, 12:17 PM	#9
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	The head should be identical or very nearly so to the 200cc model so I would go with whatever numbers Spud used in his post. I hope it is just a tight valve. __________________ Happy to serve.
	0

04-02-2013, 04:11 PM	#12
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	Well, you did it right... :wink: __________________ Happy to serve.
	0

04-03-2013, 11:21 AM	#13
m0t0 Join Date: Feb 2013 Posts: 32	I feel a bit defeated at this point. But, "Never give up, Never surrender!" I adjusted the valves according to the post i linked above and re-tested the compression. There was an improvement, but not much of one. I'm now getting roughly 40 psi instead of 35 psi. Any recommendations on where to look next? Thanks, M0t0
	0

04-03-2013, 11:58 AM	#14
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	A compression problem such as this can only come from the piston/cylinder or the head. Possible culprits include piston or ring damage, valve seating problems or perhaps a crack in the head. Next step is to put about 5-10cc of oil in through the spark plug hole and recheck compression. If it comes up a lot, say to 150 or so, the problem is likely the piston/cylinder/ring interface. If it does not come up a lot the problem is the valves and head. The step after that is you have to remove the engine . It is not possible to remove the head with the motor in place with this model. I know this from experiance. We have seen similar issues with this model a number of times. We do not know why this normally robust engine design gives such problems, but it does. I would debate selling it as is, this is what I did with mine. :? It is fixable, but I threw in the towel with mine. I think these engines develop problems early, so I figured if I fixed mine with original parts it would just puke again. :x I only paid like $150 for mine so it did not hurt my feelings to see it go. __________________ Happy to serve.
	0

04-03-2013, 01:27 PM	#15
m0t0 Join Date: Feb 2013 Posts: 32	Thanks Doc I appreciate the reply. Ill give the oil test a try tonight. I totally hear where your coming from on moving on, but this bike is actually for my wife to learn on, and she has grown attached to it so it looks like ill be in it for the long haul. :roll:
	0