Sharing my "no compression" experience

4 replies to this topic
  • diegox450

Posted July 15, 2009 - 06:57 AM


Last ride, doing some sand riding in cold weather, my bike suddenly died without any strange noise or bog... tried to start it with the electric starter, nothing, tried pumping the throttle, nothing, tried with choke on, nothing....

When the battery began to die, tried to kick her, woopss.... almost no compression!!! So, I thought that the timing chain failed or a valve was burnt...

I towed her to the town... checked the timing and it was PERFECT...
I began to think how much would cost the valve and head job. BTW I checked valve clearance and it was perfect also!! :S :S

So, I thought it didn't hurt if I check with a new spark plug and pouring a little oil inside the cylinder................ IT STARTED AT THE FIRST KICK !!!

Conclusion, the old spark plug failed, and my numerous tries to start it washed the cylinder and droped compression to almost zero... I went for a ride yesterday and the bike run great!!

I hope this post could help a little... sorry for my bad english..


  • wartsnuff

Posted July 15, 2009 - 07:02 AM


make sure you change the oil.

when you seriously flood any machine..

you need to change the oil... even if somehow you get it running..


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  • diegox450

Posted July 15, 2009 - 08:03 AM


Thanks Warts!! I didn't think about that... I'll change oil today

  • matt4x4

Posted July 15, 2009 - 10:09 AM


seems to be a common issue with 4t's and plugs - if the plug goes it goes - done fini, zippo left.
Had it happen too, but fixed it in 5 since a new plug is usually the first thing I try.

  • diegox450

Posted July 15, 2009 - 01:50 PM


Yeah, but I was scared of a timing chain or valve problem (because of the lack of compression) so I didn't try to turn the engine anymore. I always have a new spark plug in my tool set.



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