Predator 212 not starting after gx160 head

#1
So i just recently replaces the stock head with a gx160 head. I transferred everything over and now it wont start. It set valve lash to .003 on both intake and exaust. I also rejetted carb to .036 and a gx140 emilsion tube. It was running with carb adjustments before changing head. I have an autolite nascar plug and open header. If i try pulling it, it definitely has copression. It just doesnt start. White smoke comes out of exaust when trying to start. It also sometimes pops but never starts. Please help very fristrated. Thanks!
 
#5
You are saying... it now has a lot of compression...If you are feeling this by using the pull rope then the valves are not adjusted right...probably to loose. If you are using the 3910X plug you might want to swap that out to ...just to see if it helps starting conditions. Did you have the carb off ? If so are all the mounting gaskets on correctly ?
 
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#6
If you have white smoke it sounds very rich. Are you using your choke when trying to start? If so try with out the choke. Maybe after all your fuel mods you don't need to choke so much.
 
#7
You are saying... it now has a lot of compression...If you are feeling this by using the pull rope then the valves are not adjusted right...probably to loose. If you are using the 3910X plug you might want to swap that out to ...just to see if it helps starting conditions. Did you have the carb off ? If so are all the mounting gaskets on correctly ?
Well yea because the first time i put on the new head it had no compression. I then chamged head gasket and changed valve lash. (Rookie mistake, fisrt time i adjusted valve lash when head was off the block.) i did have carb off and replaced with all new gaskets. I will try swapping plug though. Still not 100% sure if valves are set right. Im new to this.
 
#9
Only use your choke for the first couple of pulls...then turn the choke off ! Also make sure your kill switch is on...:laugh: I've done that many times myself !
 

BWL

Active Member
#11
And why would you do that explain?
Because on my first build the 160 emulsion tube kept flooding the motor, and I had most of the same problem this guy is having. It enriched the mixture too much. The best combination for my motor was the original emulsion tube with the .036 or .037 jet. I believe it was the larger jet. Worked like a charm after that. The 160 emulsion tube doesn't work for everyone. Try every combination and go with what works best for you.

These ain't computers where you just plug-in-and-play. Just because forums say get this part doesn't mean it will work best your motor/situation. Different altitudes and moisture levels make a lot of difference. I say try the original emulsion tube with both jets. Throwing in a bunch of parts isn't the answer. Experimentation is.

You can check valve lashes all day, but if that emulsion tube ain't what you need, it won't work.
 
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#12
The more i mess with it the more it seems like timing. Is there anyway to change the timing. Will upping the compression mess with fhe timing? I also put 93 octane in there. Couldn that be a problem? Im just boutta throw on the old head.
 
#14
What is the process you performed to set the valve lash as you said earlier you set the valve lash with the head off the motor, if I read what you stated correctly? Did you set your valve lash on the compression stoke?
 
#15
Have you had the flywheel off ? Did you take the side cover of the engine off ? If no then its not the timing ! If you need some help setting your valve lash ...just ask . Did you have a spare spark plug ? Did you try it ?
 
#16
Have you had the flywheel off ? Did you take the side cover of the engine off ? If no then its not the timing ! If you need some help setting your valve lash ...just ask . Did you have a spare spark plug ? Did you try it ?
I agree with OND, if you haven't messed with your flywheel, your timing should be good, as long as you didn't swap cams as well, cam dot and crank dot must align. If you only pulled your head, and now it won't start it's most likely valve adjustment, however I have had my float in my carb stuck before and it would spit a little fuel out with each pull, and at that time I thought it was valves. Ensure your valves are adjusted on the compression stroke and piston at TDC.
 
#17
Compression stroke is determined when the piston is at the top of the spark plug hole.....pull your spark plug out and pull the valve cover off.
Watch the piston come to the top of the hole if one valve is still partially down.....roll the crank one round and get the piston to the top again...piston at the top with both valves closed is the compression stroke. Then you can set your valve lash.
 
#18
I always do valves by watching the exhaust valve open, close then intake open, close and after the intake closes I turn the motor 90* to 120* more and adjust valves. This pretty much works on any motor.
 
#19
Yes tried a new plug and still nothing. I didnt mess with the timing or cam or anything. Just the way it was actimg it seemed like it was off. Yes the first time around I adjusted valves wrong second time around after hitting up youtube I adjusted them what i thought was right. Top dead center then .003. I guess im gunna have to triple check tomorrow. Ill be careful as possible and i will try a bramd new plug as the other one was off of a running honda gx200. The valve adjustment is just so touchy.
 
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