Oregon dunner Posted April 12, 2012 Report Share Posted April 12, 2012 Hi guys. I am wondering on pilot size with porting. Is it common to go up in pilot size when you get a aggressive dune/drag port on a cub cylinder. Whats the best way to determine the pilot jet? how may turns is to much or not enough? My current setup is a 4mill 421, 35pwk, 52 pilot, 155 main and I think the needle is 3 clip and I am running + 4 timing I am at sea level on the Oregon coast running HJR porting Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted April 14, 2012 Report Share Posted April 14, 2012 Hi guys. I am wondering on pilot size with porting. Is it common to go up in pilot size when you get a aggressive dune/drag port on a cub cylinder. Whats the best way to determine the pilot jet? how may turns is to much or not enough? My current setup is a 4mill 421, 35pwk, 52 pilot, 155 main and I think the needle is 3 clip and I am running + 4 timing I am at sea level on the Oregon coast running HJR porting Come on guys help him out here....I'm interested in the answers to this..... Quote Link to comment Share on other sites More sharing options...
Hilarious Posted April 18, 2012 Report Share Posted April 18, 2012 Hi guys. I am wondering on pilot size with porting. Is it common to go up in pilot size when you get a aggressive dune/drag port on a cub cylinder. Whats the best way to determine the pilot jet? how may turns is to much or not enough? My current setup is a 4mill 421, 35pwk, 52 pilot, 155 main and I think the needle is 3 clip and I am running + 4 timing I am at sea level on the Oregon coast running HJR porting Your main sounds small. Might want to up it if you are running long distances or in real deep sand. I have the same pilot as you, i think 1.5 turns out on the air screws. Mine is a little rich though. Sync your carbs and set your idle and you can fine tune your airscrews from there. I would say you get to 3/4 ~ 1/2 turn out, go to the next size up. Past 2.5 turns out, go the next size down. Quote Link to comment Share on other sites More sharing options...
Hilarious Posted April 18, 2012 Report Share Posted April 18, 2012 You should notice an increase or decrease in rpm at idle while adjusting your airscrews. If not, you may have trash in your pilot jet or the wrong size. Good luck.... Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted April 18, 2012 Report Share Posted April 18, 2012 I'd say your main is too small and your pilot is too big. I'd try a 50 pilot and 162 main. Quote Link to comment Share on other sites More sharing options...
Oregon dunner Posted April 19, 2012 Author Report Share Posted April 19, 2012 Thanks guys. I dropped my pilots back down to 50 and I went up to a 160 main and 1.5 turns out. I will see what happens when I head back out to the dunes. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted May 2, 2012 Report Share Posted May 2, 2012 Your main sounds small. Might want to up it if you are running long distances or in real deep sand. I have the same pilot as you, i think 1.5 turns out on the air screws. Mine is a little rich though. Sync your carbs and set your idle and you can fine tune your airscrews from there. I would say you get to 3/4 ~ 1/2 turn out, go to the next size up. Past 2.5 turns out, go the next size down. what size mains do you run? Quote Link to comment Share on other sites More sharing options...
Hilarious Posted May 2, 2012 Report Share Posted May 2, 2012 what size mains do you run? I used a 175 in my drag bike when it was on gas. Im also using a 175 in this new motor I just built and it seems to like it as well. Quote Link to comment Share on other sites More sharing options...
Sweet1 Posted May 2, 2012 Report Share Posted May 2, 2012 Im at a 50 pilot, 160 main, non ported 421 cub. it may be tad rich, on the oregon coast. ever come to coosbay? pics of your bike so i know when i see it? Quote Link to comment Share on other sites More sharing options...
Oregon dunner Posted May 3, 2012 Author Report Share Posted May 3, 2012 Im at a 50 pilot, 160 main, non ported 421 cub. it may be tad rich, on the oregon coast. ever come to coosbay? pics of your bike so i know when i see it? I come to the coast all the time. I usually ride my CRF 450. When I get tired of the that I head to the steep tree shots or Idiot holes right next to the water. This is what my banshee currently looks like. Soon to have white plastic with some paint. Quote Link to comment Share on other sites More sharing options...
Sweet1 Posted May 3, 2012 Report Share Posted May 3, 2012 thats funny, mines all blue plastic, candy blue frame...... i like blue have you run it with the 155 main? just curious. Quote Link to comment Share on other sites More sharing options...
Oregon dunner Posted May 4, 2012 Author Report Share Posted May 4, 2012 thats funny, mines all blue plastic, candy blue frame...... i like blue have you run it with the 155 main? just curious. I have ran it at the drags with a 155 main. Seems to run fine. Quote Link to comment Share on other sites More sharing options...
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