facebook1 youtube1 twitter1 instagram google plus linkedin1 pinterest1

logosmallNOTICE:  If you are not a free registered member of the site, you will not see the photos in the forum, and you won't be able to access our premium member content. Please consider joining our community!

Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1
  • 2

TOPIC: 1981 dt100 tuneup help

1981 dt100 tuneup help 13 Jun 2019 13:05 #11

  • yamahahaha
  • yamahahaha's Avatar
  • Offline
  • Site Contributor
  • Site Contributor
  • Posts: 529
  • Likes received: 140
Gee I wonder who on this forum always says clean your carb , clean it again then clean it again :whistle:

Was it Mako

Please Log in or Create an account to join the conversation.

Last Edit: by yamahahaha.

1981 dt100 tuneup help 13 Jun 2019 15:34 #12

  • Wheel mad
  • Wheel mad's Avatar
  • Offline
  • Sportsman
  • Sportsman
  • Posts: 134
  • Likes received: 127
If it will only run on choke and your 100% that carb is clean and float level right, it might be an air leak.
With engine running, try spraying wd40 or similar around the base of the cylinder and carb mount/reed block, if it picks up revs, there is the leak.
Could be crank seals I suppose, but for me they either work or they don't.

Another thing to try . Bypass or replace the spark plug cap.

Please Log in or Create an account to join the conversation.

1981 dt100 tuneup help 13 Jun 2019 15:52 #13

  • RT325
  • RT325's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 3939
  • Likes received: 1265
Talking carburetors you should only have to clean it once but clean it properly!!.
The following user(s) Liked this Post: Devin

Please Log in or Create an account to join the conversation.

1981 dt100 tuneup help 13 Jun 2019 20:33 #14

  • Hrspowr
  • Hrspowr's Avatar Topic Author
  • Offline
  • Newbie
  • Newbie
  • Posts: 6
  • Likes received: 0
Ok..... took the common thing I have seen on all these “can’t get it to run right” thread, and went through the carb once again. Every jet is clear, compressed air through every port on the carb. Reassembled, now runs better, but still won’t idle, even with idle screw all the way tight. Revs quicker now, but doesn’t top out, seems to hit a stop, and sputter?

If I rev it in neutral, it climbs then sputters.

Does the same with the air box taken off.


It now doesn’t need choke to stay running, in fact once warm, choke makes it stumble pretty bad. Checked for air leaks, doesnt seem to be any. It is obviously not topping out on revs.


I can hold the throttle a little, and it “idles” fine. But idle screw doesn’t make a difference.

Please Log in or Create an account to join the conversation.

1981 dt100 tuneup help 13 Jun 2019 20:35 #15

  • Hrspowr
  • Hrspowr's Avatar Topic Author
  • Offline
  • Newbie
  • Newbie
  • Posts: 6
  • Likes received: 0
I HAVE only cleaned the card 4 times now, so maybe I just need to do it a couple more times?!?!?

Please Log in or Create an account to join the conversation.

1981 dt100 tuneup help 13 Jun 2019 21:59 #16

  • Mothersbaugh
  • Mothersbaugh's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 1257
  • Likes received: 619
Just curious. You sure sure you know where all the orifices and passageways are? Not trying to insult you. Got all the white stuff out of the bowl? Cleaned out the inside of the main jet holder?

Please Log in or Create an account to join the conversation.

1981 dt100 tuneup help 14 Jun 2019 00:15 #17

  • RT325
  • RT325's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 3939
  • Likes received: 1265
Can you do a video with good audio going through idling revving & medium throttle, or even riding around would be better just going through the throttle rang, then standing there giving it a good rev but opening from idle so we can hear it come up in the revs & see how high it revs to. Thanks.

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
  • 2
Moderators: VinnieDEETyamadminDmanEnduronutMakotosunDevinJames Hart