Box Stock

What did I do wrong?

J

Jasona1975

New member
I have a 212 non hemi.
Only mods are governor delete, air filter adapter and filter, header pipe, and 18 lb valve springs. The springs were done last and up until I changed them my engine ran perfectly. As soon as I installed the springs, my engine began to run like ****. Idles like crap, dies when giving it gas, power cuts in and out, spits and sputters. I took it to a shop to make sure the valve lash was correct and they said I needed a bigger jet because of the springs. I installed a .038 jet and it made absolutely no difference. I don't know much about small gas engines so any and all help would be greatly appreciated. I'm to the point of putting the stock springs back in it because at least it ran good. I'm not building a race bike or trying to go all modded out. I just wanted a little more speed and power other than stock. I was happy with it before I changed the springs and now I'm disgusted with the way it's performing. Someone please help!!
 
Springs alone won't do that .
How did you change them ?
Absolutely sure you did not change or adjust anything ?
 
I brought it to a place in town that builds racing outlaw karts and sells parts.
One of the valve spring keeper halfs fell into the head and I pulled it to get it out. Re-torqued the head to 17lbs (w a new gasket)
and tried to set the lash. The engine wouldn't start so I took it to the shop. And this is where I am at today. The tech told me to change the jet and if that didn't work, bring it back and he would look at loss of air to fuel mixture or something along those lines. (Carburetor related) Is what I understood. I didn't think I'd need to buy another carb when the stock was doing just fine for my application. I'm not trying to win any medals or trophies for speed, I just wanted to go faster than out of the box and sound good getting there lol. I'm not trying to spend a bunch of money hopping up a motor just to ride up and down the road from time to time. It is all more of a "what should I do with this Doodlebug I got for free?"
 
For right now, I would get a new head gasket and go ahead and take it apart again.
You can either go with the old springs or the 18 lb springs. The stock springs should get you nearly to 58-5900 before causing too much problem.

The 18 lb springs would be part of a foundation for increased power, like from a more aggressive cam and/or a larger carburetor. They would allow the motor to turn more rpm without floating the valves, but are not necessarily going to increase the power on their own. In fact, they could do the opposite to a minor level, due to parasitic loss- or causing needless extra friction.

Make sure you set the valve lash correctly, and keep asking questions.
 
You changed the air box to an after market adapter and filter but I didn't hear you say anything about changing jetting on the low or top side. You must change jetting as well. No need for another carb
 
Don,
He said that every was fine after the filter and pipe change, that the problem started after the spring swap.
He also mentioned that he went to a 38 jet with no change.
 
To those who responded, I really appreciate all your advice and knowledge. I took my carb off and completely disassembled it and cleaned it. While I was putting it back on, I noticed I had the 3 gaskets mixed up and I found out my engine will NOT run with the autolite ar3910x racing plug. I put the stock plug back in and after the carb was reassembled and reinstalled it started on the 2nd pull. I'm pretty stoked about it. Now if it would just quit raining I could go break it in proper. So to all of you folks out there, thank you all very much. I hope I can one day be a response to someone's dilemma as y'all have been to mine.
 
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