Trouble keeping my 77 Enticer 250 running

M

markbec2

New member
Joined
Oct 13, 2004
Messages
7
Age
52
Location
Pinckney, Michigan
I bought the sled with the carb off, I reinstalled it I can get the sled to run with the choke on but it runs super rough, and starts to run rougher after a minute or two then lightly backfires and quits any simple ideas?
Thanks
 
Carb

Pull the carb back off and clean it. It sounds like the main jet or the pilot may be gunked up . Make sure the pulse hose is connected to the crank case.
 
That should be a Keihin diaphragm carb on there. Did you adjust the fuel level at the sight tube? Rebuilding a diaphragm carb is a little more involved and tedious than a slide carb. The adjustment process is as follows . . .
  1. Back off the adjuster nut on the bolt in the bottom of the carb. If you have had it apart or are unsure of it's current setting - six full turns in is a starting point. Start the sled and adjust the fuel level until it is at the joint between the carb body and the pump body. Be sure to control idle speed during this step as it affects the level. I have found that 4 1/2 - 5 1/2 turns in (from falling out) is usually where it ends up. Be sure to tighten the locknut well as these bolts like to loosen and fall out.
  2. Adjust the idle mixture screw until the engine runs the best and then open it a little (1/8 - 1/4) turn to aid acceleration.
  3. Readjust the idle speed to 2000 rpm's - I use a Tiny Tach for this.
I am guessing that your fuel level may simply be too high. I have found that if it cannot be adjusted with the bolt on the bottom, then the needle valve inside is not working correctly and it needs rebuilding. Getting this carb on and off the machine is a pain, but it is the only way I have found to work on it. You got to love those nuts on the oil pump shaft. I forget the size but it is like 3mm Fine. Try to find that at your local hardware store. I had to order some online.
 
I have one doing the same thing right now. It was running fine for most of last year, but at the end of the year it began to flood. I still haven't found the problem. These can be finicky buggers.
 
The screw in the bottom of the carb on these is famous for dropping out. That wouls cause some problems. Easy to check. If the screw is gone goodluck finding a aftermarket one. I am in the process of switching over to a mikuni roundslide due to unavailabilty of screw.
 
Ding said:
I have one doing the same thing right now. It was running fine for most of last year, but at the end of the year it began to flood. I still haven't found the problem. These can be finicky buggers.
Click to expand...


ding, take it off and check the diaprams. we have a 79 and if you filled it up it would flood the motor. under 1/2 tank it was ok. just hope you do not have the "other" carb like i do. aparently yamaha put 2 different cabs on this sled. i just happen to have the rare large one.
 
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