Coleman BT200X help

#1
Hey guys,

Sorry my first post is asking for help, but I am not sure what to do at this point. I purchased a BT200X a couple months ago and have taken it out a total of 3 times on some back trails. Here is the order in what happened:

-Purchased bike and put together
-Cut off the tack-welded throttle screw
-Took it on a 5/6 mile trail ride and everything was great
-Took it on a 3/4 mile trail ride - steep and rocky, so I was on the throttle a lot. About halfway up it seemed like the throttle was stuck open and I was riding the brakes a lot. If I would let up the brake, the bike would take off. I turned around and basically coasted back down the trail to the truck. Thought it was the throttle, but it seemed like the governor arm wasnt returning all the way to closed.

-After taking off the air filter and carb, taking off the gas tank and evaluating all the springs, I ordered and replaced all of the springs on the throttle and governor arm.

-I talked to a couple small engine mechanics over the phone and they indicated that the carb might be the issue - like stuck float pins or something.

-I ordered the stage 1 performance kit from GoPowerSports and also a new carb with the jet already installed.

-I put the new air filter on yesterday and the header, the new carb, and reconnected all of the throttle springs, and the carb is still not closing and I think it definitely has something to do with the governor arm.

-I put a make-shift spring on the governor arm going backwards to pull the arm tight to the closed position. I started the bike and it was running fine at first, took it up and down the street, then gave it full throttle and all of the sudden I got a huge surge in power/speed. I tried to slow down, but the carb seemed to be stuck open again. Took it back in the garage, looked at the governor arm and it appeared to still be pulled back and closed per the spring I put on there. I then started it up in the garage and it took off like a bat out of hell. I ran next to it and luckily was able to hit the kill switch before it was gone. Pulled the bike back in the garage and called it enough for the night.

-With the gas tank moved to the side I started looking at the governor arm - there is a T screw that goes through it and a nut to tighten on the other side. There is also a pin to hold it together. I have zero clue on what could be causing the governor arm not to return? Is it because I was running it heavy on the steep and rocky trail and something gave out? I would like to just remove the governor all together, but I am not super technical when it comes to cars/trucks/bikes/engines.

At this point I'm debating on taking to it a small engine repair guy or continuing to try to figure this out myself. It sucks, since I have only gotten 2.5 days of riding out of it and its kind of dead in the water at this point.

Any help, ideas on what to try, direction, or anything at all would be super helpful. I appreciate any help anyone is willing to give.

Thanks and sorry for the long drawn out explanation, but I wanted to give the best picture of what has happened since I got the bike.

Trevor
 
#3
Not the best quality of videos but maybe this is your problem. I've heard a few people having this issue.

Thanks!! I appreciate the help a lot. I don't think thats it. The throttle seems to open and snap closed like it should. Per the comments in the video, I found a guy with the same issue I've got:

EJ S3 weeks ago
Hey, nice try bud! Anyone who has the bike in front of them will get the jist of what you are trying to explain.... My issue is that the butterfly is staying stuck open. The throttle is actually working perfectly. Bike road around great for the first couple easy rides. The first time i went wide open on it, the throttle seemingly was stuck open. Luckily i am quick on the kill switch after a couple hard lessons : / Upon further investigation as i said, The complete throttle mech. is working properly. (Very snappy) A bit stumped... I can manually open and close the butterfly valve like butter, but then it returns to full throttle. (Like governor is not returning the butterfly to closed position) Anyway, i applaud your attempt. You are absolutely correct these are dangerous machines. Thank goodness this happened to me and not 1 of my kiddos!


REPLY
 
#4
Been trying everything I can think of, but I can't seem to get the governor arm to return. I've tried turning the inner screw on top of the governor arm, but cant seem to get it to return back. Is it possible that the governor itself inside is shot?

Sitting there:


Holding the governor arm back:


You can see the carb is wide open unless I pull the arm back. I'm clueless at this point. Any ideas would be huge
 
#10
Remove it and replace the governor or tap the hole. If you remove be careful with your rpms.
Is there anything I can do to make it handle the higher RPMS with the governor removed? Torque converter kit? I know I prob need to put 18 lb valve springs in there if I take out the governor.

Thanks a ton for your guy's help, I really appreciate it
 
#12
If you are a sensible person with self control remove the governor , install 18lb springs and some 1.3-1 ratio rockers , get a tachometer installed and don't run over 5000 rpms. As noted above a billet rod and flywheel is certainly the best bet .
 
#14
Thanks a ton. I am not super technical when it comes to working on bikes and cars, but that kit is exactly what I was looking for instead of trying to piece together the things I "think" I need. Are there any specific tools that I'll need to buy? I was planning on getting a torque wrench to make sure I get the lbs right, but not sure on anything else that would be crucial.

Thanks again for your help
 
#16
Sorry for reviving this thread, but after much debate I am just leaning towards spending $100 on a new predator engine instead of spending $150 to buy the governor removal kit and go through trying to do it myself.

Questions if you guys have time/knowledge -

Is there an easy way to tell if I need to get a crankshaft conversion?

From an older post I found:

From SAS289 "The factory Coleman engine's shaft size can be figured out by the last 6 digits of the VIN. Last 6 037962 and after are 5/8. Any number before that has the 3/4" shaft." Mine is 142362 so I'm assuming 5/8.

My questions are:

Will a 5/8 to 3/4 inch crankshaft adapter sleeve work? Something like this?

https://www.amazon.com/Engine-Pulle...1&refRID=NE05N6FJC69D94G0AHBG#customerReviews

I'm also wondering if I would need a mounting plate or something or if it should bolt right up? Just trying to think of anything else I might need or im forgetting.

Any tips/ideas/guidance is super appreciated. I'm mostly just concerned about getting a running bike at this point. I bought this to use for some backcountry scouting and also shuttling the drift boat, so I don't need to have it hot rodding at this point, just running. Thanks a lot
 
#18
Here's the thread I started about the 5/8 shaft. I got it to work.

https://www.oldminibikes.com/forum/index.php?threads/5-8-to-3-4-crankshaft-conversion.166811/

For me it looked like the adapter may work on it's own but I didn't trust it.

I bought the riser plate from OMB which lifts the engine up and forward so you don't have to cut the chain guard bracket.
Thanks for that - I read that thread previously, but I am not super mechanically inclined, so I was having trouble following what you did. I wish there was someone I knew around here that had experience on small engines. Everyone I've called has said they don't work on them.

I'm starting to think this thing is gonna sit in my garage as a $500+ display. My head just hurts trying to figure out what parts are/might be needed and what is gonna work or not. Thanks for your guys' help I really do appreciate it
 
#19
You might want to get another engine just to get the bike going, and then work on this engine in the meantime.
That way you can take your time and not be stressed trying to fix this engine.
I built 2 engines for my MTD so I could ride the bike while also building an engine. It worked out pretty well.
 

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