BT200X Valve spring swap

#1
Hey there, I’m hoping someone could help me out here. I recently bought a brand new Coleman bt200x. I put a GPS stage 1 kit on it, cut the throttle screw and did the zip tie trick for the governor. Today I went to change my valve springs out from stock to 18 lb springs. Once I thought I had them situated using a feeler gauge I put the bike back together and went to start it up and the pulley was incredibly hard to pull. I pulled a few times and then opened the head back up to adjust the valves. Once again put the bike back together and the pulley was still hard to pull. After a few pulls the string snapped on my pulley. The bike never started after opening up the head and changing the springs. Could someone please give me some insight on what I may be doing wrong? Thanks so much.
 

SAS289

Well-Known Member
#2
Well, the first thing you are doing wrong is that you are going to run too high an RPM on the stock flywheel and internals. You really should consider a billet rod and flywheel.

You need to set the valve lash while the piston is sitting at TDC. With the rocker cover off and the spark plug out place a long screwdriver into the spark plug hole gently touching the piston. Slowly pull the cord to spin the engine. Watch the intake valve open then close. At this point the piston should be rising and pushing the screwdriver out. Go very slow with the pull cord and the very second the screwdriver starts going down stop there and adjust the valve lash.

My opinion on the Coleman 200's is that if you want to go faster than 25 build a higher RPM engine that includes a billet rod and flywheel, or just install a torque converter. You don't need a high RPM engine to get 35-40 on a Coleman 200 with a torque converter. Or 18 lb valve springs.

With the 18 lb springs you may get to 7000 RPM or so. This is not a good idea with the stock flywheel and rod. Pretty risky.
 
#3
Well, the first thing you are doing wrong is that you are going to run too high an RPM on the stock flywheel and internals. You really should consider a billet rod and flywheel.

You need to set the valve lash while the piston is sitting at TDC. With the rocker cover off and the spark plug out place a long screwdriver into the spark plug hole gently touching the piston. Slowly pull the cord to spin the engine. Watch the intake valve open then close. At this point the piston should be rising and pushing the screwdriver out. Go very slow with the pull cord and the very second the screwdriver starts going down stop there and adjust the valve lash.

My opinion on the Coleman 200's is that if you want to go faster than 25 build a higher RPM engine that includes a billet rod and flywheel, or just install a torque converter. You don't need a high RPM engine to get 35-40 on a Coleman 200 with a torque converter. Or 18 lb valve springs.

With the 18 lb springs you may get to 7000 RPM or so. This is not a good idea with the stock flywheel and rod. Pretty risky.
Thanks so much for the response! I actually have a torque converter coming in the mail.
Would you suggest I cut the zip tie and leave the governor alone, put the original springs back in the bike and call it a day after the torque converter is installed? With the torque converter and the stage 1 kit I’ll be fine with the stock springs, right?
 

SAS289

Well-Known Member
#4
Thanks so much for the response! I actually have a torque converter coming in the mail.
Would you suggest I cut the zip tie and leave the governor alone, put the original springs back in the bike and call it a day after the torque converter is installed? With the torque converter and the stage 1 kit I’ll be fine with the stock springs, right?
Yes. If you don't want to open the engine run with the original governor setup the bike came with and install the torque converter. A stage 1 kit and torque converter work great on those bikes and you will not run too high RPM. Leave the throttle screw out.

The stock springs will easily handle the RPM so you will not need the 18 lb springs.
 
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