Cody_t123 Posted July 26, 2017 Report Share Posted July 26, 2017 Hey guys, just finished building my 4mil long rod, ported stock cylinder build on my banshee. After heat cycles and running multiple tanks through the bike, I loaded up and took the bike to Winchester bay. While there, I faced nothing but dissapointment in my new build. The bike was getting beat by my buddies stock banshee up banshee hill. This was extremely dissapointing due to the fact that prior to the build, my bike was consistently 1-2 quad lenghts ahead of him. the powerband feels extremely short and it is hard to even get the front end off the ground. It sounds like it is running very crisp and clean but the power is lacking. 3rd gear tops out almost instantly after shifting and then 4th gear is a struggle to hold rpms. I am running my stock carbs with 370 main jets and 30 pilots. I have tried 28mm flat side mikunies and got all the way up to 410 mains and it was still acting extremely lean. Spark plugs were backing out. This is when i switched back to the stock carbs and it made it run much more crisp and stopped backing the plugs out. I have 19cc stroker domes in my pro design cool head also paired with the weisco 795 pistons, hot rods 4mil crank with the 115 long rods and no spacer plate. My cylinders are an agressive dune port set up for a 4mil and they were ported by Carl. my timing is advanced +4, I am running 10 paddle haulers with a 14 tooth front and a 43 tooth rear sprocket. Anybody got any suggestions on trouble shooting this? 1 Quote Link to comment Share on other sites More sharing options...
blowit Posted July 26, 2017 Report Share Posted July 26, 2017 What fuel are you running? What pipes? Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 56 minutes ago, blowit said: What fuel are you running? What pipes? 110 race gas mixed at 45:1 and LRD adjustable pipes which are the same pipes as I ran before the build Quote Link to comment Share on other sites More sharing options...
ginger Posted July 26, 2017 Report Share Posted July 26, 2017 have you done a plug chop? btw normally if plugs are backing out, its detonation. Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 1 hour ago, ginger said: have you done a plug chop? btw normally if plugs are backing out, its detonation. yes, plugs look good now, when i swapped back to my stock carbs, the detonation stopped and the spark plugs stayed in but it is still slower than it was stock lol Quote Link to comment Share on other sites More sharing options...
ginger Posted July 26, 2017 Report Share Posted July 26, 2017 same tires and sprockets as before? if the gears are really short, it would make me think gearing or jetting. Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted July 26, 2017 Report Share Posted July 26, 2017 What is your cranking compression? Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 31 minutes ago, ginger said: same tires and sprockets as before? if the gears are really short, it would make me think gearing or jetting. yup, tires and sprockets are the same so it should at least go as good as it did before right? lol Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 7 minutes ago, Ayesully810 said: What is your cranking compression? will check compression again when i get home Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted July 26, 2017 Report Share Posted July 26, 2017 Have you done a leak down test? Sent from my VS990 using Tapatalk Quote Link to comment Share on other sites More sharing options...
SandSlingerOR Posted July 26, 2017 Report Share Posted July 26, 2017 Lrd s are probably holding you back a bit. Try some cpi s, what size rear tires? For 20s rear tires I like 14-41 or 43's like your running. Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 15 minutes ago, hercalmighty said: Have you done a leak down test? Sent from my VS990 using Tapatalk leak down test was done before i put the motor back in and it held 8 lbs for over 15 minutes. After the 15 minutes it started to drop a little but i think that was leaking out of the tester. I will do another test now that it has ran a bit when I get home tonight. Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted July 26, 2017 Report Share Posted July 26, 2017 (edited) 27 minutes ago, Cody_t123 said: will check compression again when i get home again? what was it when you checked it after the re build? You should be at least 170 psi in each cylinder with compression with that 110 gas. If not that will explain a part of your problem. Carl does top notch work. Edited July 26, 2017 by Ayesully810 Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 14 minutes ago, SandSlingerOR said: Lrd s are probably holding you back a bit. Try some cpi s, what size rear tires? For 20s rear tires I like 14-41 or 43's like your running. Running 20" 10 paddle haulers. I had a 41 rear before and I went to 43 hoping I could pull 4th gear up banshee hill but it didnt change anything. I like my LRDs but I am sure I could get a bit more out of a CPI or Shearer inframe Quote Link to comment Share on other sites More sharing options...
Cody_t123 Posted July 26, 2017 Author Report Share Posted July 26, 2017 2 minutes ago, Ayesully810 said: again? what was it when you checked it after the re build? You should be at least 170 psi in each cylinder with compression with that 110 gas. If not that will explain a part of your problem. Carl does top notch work. I checked it once before I was done with heat cycles and it was only at 125 psi each, but I think the rings werent completely seated when I checked so I will check again when I get home. And yeah Carl is a good guy, if I cant figure it out, we are going to meet up and see if he can figure out what is going on. Quote Link to comment Share on other sites More sharing options...
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