Question About Baja Heat Idle

Bones

Bones

New Member
#1
#1
Hello,

I'm brand new here and it's my first post. I have recently began to work on my sons Baja Heat Mini Bike [I'm ordering a new clutch] and the idle just seems to be high. I read a post here where factory idle is 1500 rpm. I want to make sure I have the idle correct before installing a new clutch. I've watched some Youtube videos and the bikes seem to idle slower than this one. Just thought I would get some opinions. Here is a video....

‪idle‬‏ - YouTube

Here is a video from when I was troubleshooting the clutch. I removed and cleaned the rust, reassembled and installed with the same results. The bell is not locked but the minute the engine fires, the clutch engages....

‪Centrifugal Clutch‬‏ - YouTube

Thanks for any input. I would love to get this thing up to speed and maybe mod it a little.
 
C

C9H13NO3

Active Member
#2
#2
Lower your idle.

There is a black plastic screw on the carb, near the throttle butterfly.

Turn it counterclockwise with the bike running and you'll hear the rpms drop.

Turn it out to the point where the engine will stay running, but won't engage the clutch.

If you want, you can go with a Header, Filter, and re-jet.

All of these parts can be bought from www.OldMiniBikes.com
 
Bones

Bones

New Member
#3
#3
Thank you for the info, instructions and link. Much appreciated. Hopefully I will get the opportunity to get into it tonight. I have the clutch off right now but will reinstall and lower the idle. I was thinking that may be the source of my clutch troubles.
 
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C

C9H13NO3

Active Member
#4
#4
Bones said:
Thank you for info, instructions and link. Much appreciated. Hopefully I will get the opportunity to get into it tonight. I have the clutch off right now but will reinstall and lower the idle. I was thinking that may be the source of my clutch troubles.
Click to expand...
No problem.
 
Bones

Bones

New Member
#7
#7
C9H13NO3 said:
Yes, it is.
Click to expand...
OK thanks, I wanted to make sure. I turned it counterclockwise at least 2 complete turns or so [hard to tell exact turns, it's a tight fit in there] with no change in idle. I'll give it another try tomorrow. It did sputter a couple times though backing the screw up. Thanks again for the help. I'm not a complete stranger to small engines, but carbs I have never really wrenched on.
 
C

C9H13NO3

Active Member
#8
#8
Bones said:
OK thanks, I wanted to make sure. I turned it counterclockwise at least 2 complete turns or so [hard to tell exact turns, it's a tight fit in there] with no change in idle. I'll give it another try tomorrow. It did sputter a couple times though backing the screw up. Thanks again for the help. I'm not a complete stranger to small engines, but carbs I have never really wrenched on.
Click to expand...
Post a picture of your linkage. When you turn that screw counter clockwise the idle should drop. I'm thinking that you are missing a spring somewhere.
 
Bones

Bones

New Member
#10
#10
OK, I hope these are clear enough. If not I can take others.

















I also took a closer look at what is happening when the screw is backed off. The black piece that makes contact with the screw at idle is not moving past a certain point. In the video I am manually pushing it with a screwdriver until it makes contact with adjustment screw.

http://www.youtube.com/watch?v=E5dl_Y2yRmU

I noticed that under the tank there are "adjustment" holes where the rod is hooked up. Should I move the hookup one hole to the right? It seems that if I do, it will move part that pivots closer to the screw.

 
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Erok000

Erok000

Member
#11
#11
Your thinking is probly correct. I had that problem and was gonna tell you to push the black throttle part( im bad with names of parts) onto the screw and see if it not making correct contact. And you did that. Make sure that spring is loose until you pull the throttle! Maybe moving holes or taking the spring off and bending it a lil to fit better. since you moved the idle screw you might have to move it back( or not) to make the right adjustment. I hope that makes sense and helps a bit!

GL
Korey:scooter:
 
J

Justin9

New Member
#13
#13
it's almost like your throttle return spring is either broken, missing, or very weak, and because of that, the natural vaccum created by the engine is pulling the throttle butterfly open and that makes the engine idle up...
 
Bones

Bones

New Member
#14
#14
Justin9 said:
it's almost like your throttle return spring is either broken, missing, or very weak, and because of that, the natural vaccum created by the engine is pulling the throttle butterfly open and that makes the engine idle up...
Click to expand...

It seems to be ok. I snapped a picture being that I have the tank off. Just the slightest movements cracked the factory fuel line. :scared: Will be replacing asap......

 
Bones

Bones

New Member
#15
#15
I replaced the fuel line and put everything back together. I put the linkage back into the first hole, but did reroute the throttle return spring. The idle is much lower now and reacts to the screw adjustment. I will fine tune it but all seems to be much better. My next step is to re install the original clutch now that I can control the idle and hopefully will be mobile shortly. If not I will order a new cluth, or at least a spring. Thanks for everyone help so far........

‪idle 4‬‏ - YouTube
 
J

Justin9

New Member
#16
#16
my firewall at work blocks the pictures usually, so if you had them in a post I couldn't see them... however, I can watch youtube videos, go figure...

also get you a piece of plumber's sandpaper aka emory cloth its basically a piece of 120 AO sand paper, but about one inch wide. With the engine running, you can "sand" the crank shaft very easily and clean up the crank with what appears to be rust on it... this will help your clutch slide on much easier...

It isn't that hard to do with the engine turned off actually, I do that all the time on my engines, if you want to go the extra step, I put just a very light dap of anti-seize on there too, to help keep the clutch from getting moisture between the hub and the crankshaft.
 
fonz

fonz

New Member
#18
#18
That Black return spring I am almost positive that is your trouble!!! It should go in front of the engine cover!! Not behind it!! I painted my cover on another bike yesterday and when I installed the new painted cover today I had a "RUN-A-WAY" bike!!! Simply because I had the spring on the back side of the cover and it screwed my linkage up!!! Make sure that black spring is completely visible on the front side of the cover!!
PS I just went outside and checked my other two motors and both have that black spring in front of the cover. Take the cover off and just move the spring in front and replace the cover.
Good Luck!!
 
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