No compression
Apr 9, 2018 | 08:42 PM
#1
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Weekend Warrior
Joined: Apr 2018
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No compression
I have a 93 Yamaha Warrior 350 and I have 0 compression. The piston and rings we changed. It’s on tdc I have spart on the plug I have a new carb. It was running and smoking unit my son replaced the piston. Could it be the heads or the timing chain. I’m lost I would like some help or suggestions if possible.
Apr 10, 2018 | 04:11 AM
#2
Elite Pro Rider
Joined: Oct 2013
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From: Lancaster England
Check the valve clearances at TDC on the compression stroke. If they are OK check valve timing. If it is OK now, he may have got it wrong, then righted it after the piston hit a valve and bent it. Either way the head is going to have to come off to check head gasket was OK, valves for being bent, and rings for not being the right ones, or scoring the bore for some reason.
Apr 10, 2018 | 07:53 AM
#3
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Weekend Warrior
Joined: Apr 2018
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No compression
I removed the head off and checked the valves the don’t seem to be closing all the way. I turned them around and sprayed some wd40 on then and it all went threw. I guess that means I have a bad cylinder head or valves.what would my next step be.
Apr 10, 2018 | 11:19 AM
#4
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Tell me more about the "piston replacement"...did he just throw in a new piston or did he send the cylinder out to have it bored and have piston/rings matched to it?
Head - not sure what your skill level is, but I'd pull it apart and clean/inspect everything...
Cam - ensure the lobes are in good shape and within spec...
Head - not sure what your skill level is, but I'd pull it apart and clean/inspect everything...
Cam - ensure the lobes are in good shape and within spec...
Apr 10, 2018 | 11:40 AM
#5
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Weekend Warrior
Joined: Apr 2018
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No compression
when my son got the bike they gave him a box that had the new piston and rings along eith the gaskets. Him and a friend put them on and all went diwn hill from there. I believe they messed up the valves but its hard me me to say im not good at mechanics i tild him go search for a new cylinder head. They installed a new cam chain
Apr 10, 2018 | 11:54 AM
#6
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Take the head to a shop and have them grind the valves and install new valve seals in it buy a new top end gasket kit. pull your jug and piston and take that in to get measured. if the jug specs out with the piston sixe hone it a little for new cross hatches and put a new set of rings in it.
Apr 11, 2018 | 08:47 AM
#7
Pro Rider
Can't wait to feel that 130 HP at the dunes.
Can't wait to feel that 130 HP at the dunes.
Joined: Nov 2003
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From: Arlington WA.
Pull the cams and see if they close. If the valves don't close they are most likely bent, will need new ones.
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Apr 23, 2018 | 07:09 PM
#9
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Weekend Warrior
Joined: Apr 2018
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Timing
Thanks for all the help and input about not having any compression. That issuers was resolved the woodruff key was slipping and finally broke. Now my issue is that my warrior 350 starts fine when I have the choke when I turn the chicke off it shuts down I’d i give it gas it hesitates. What could that be the carb is new