jst854 Posted August 12, 2010 Report Share Posted August 12, 2010 (edited) I have been trying to get this bike jetted for about a month now. It is a 4 mil long rod with the domes cut, dont remember the dome size but it has about 160 psi and i am running 114. It has a cool head, VF3's, timing +4, very close to a full out drag port, CPI inframes, and 35mm mikuni carbs. Currently I am at 70's for the pilots and 580 at the mains. The clip is in the bottom position. This is by far the best it has run with the jetting as I have tried everything from 200 through 600 and 30 through 80 for the pilots. The bottom end is good but as soon as it hits the power it seems to not want to pull and sputters. Here is a short video of it. Let me know what you guys think as I am stumped. Edited August 12, 2010 by jst854 Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted August 12, 2010 Report Share Posted August 12, 2010 Did you do a leak down test? You shouldn't be jetted that rich. Quote Link to comment Share on other sites More sharing options...
jst854 Posted August 12, 2010 Author Report Share Posted August 12, 2010 yes I did a leak down test and it held 5 pounds for 5 mins what would you recommend as a starting point? Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted August 12, 2010 Report Share Posted August 12, 2010 What's your elevation? What are you running for air filters? What is your oil ratio? Did you make sure everything is working right in the carbs? Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted August 12, 2010 Report Share Posted August 12, 2010 What we have here is a learning experience except those that know it all and those that think they do. Taking that big of a swing at jetting leads me to think there is something else going on. What did the plugs look like at 200 main and 600 main? Couldn't tell from vidieo , but almost looks like it's smoking more out of right, but leakdown seems to rule bad seal out. Check carb vent lines , small mud daubber wasps like small holes to lay an egg. Go back thru everything. What plugs? Check tank vent ,fuel flow . Is this a fresh build? No nests in pipes or silencers? Float level? What pipes do you have? Sorry this is a little disjointed , just things as I think of them. Let us know what you find , as at least I want to know/learn. Maybe plug boots? Quote Link to comment Share on other sites More sharing options...
jst854 Posted August 13, 2010 Author Report Share Posted August 13, 2010 What we have here is a learning experience except those that know it all and those that think they do. Taking that big of a swing at jetting leads me to think there is something else going on. What did the plugs look like at 200 main and 600 main? Couldn't tell from vidieo , but almost looks like it's smoking more out of right, but leakdown seems to rule bad seal out. Check carb vent lines , small mud daubber wasps like small holes to lay an egg. Go back thru everything. What plugs? Check tank vent ,fuel flow . Is this a fresh build? No nests in pipes or silencers? Float level? What pipes do you have? Sorry this is a little disjointed , just things as I think of them. Let us know what you find , as at least I want to know/learn. Maybe plug boots? I am around 1000ft for elevation. The plugs are 8's, the engine is fresh, brand new crank, pistons, head, carbs, and pipes. The filters are clamp on's with prefilters. I have a oversized petcock and the stock vent on the fuel cap, could that keep it from getting enough fuel? I have not checked the plug boots yet, I will switch them out for a pair that I know is good. I do not have room to do a plug chop around here so I can't get a accurate reading on the plugs. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted August 13, 2010 Report Share Posted August 13, 2010 Two other thoughts. Pick-up coil gap. Could cdi be getting ready to take a dump? Seeing you just had engine apart would presume poles on stator are clean, how about pick-up lugs on flywheel? Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted August 13, 2010 Report Share Posted August 13, 2010 Wow I'd think 250 to 280 for mainjet ck coil ground, pickup gap like he said. . Ck float level, get new NGK plug boots for $8, borrow a coil and cdi to try, if its got a ricky stator it may be junk and goin out. Quote Link to comment Share on other sites More sharing options...
jst854 Posted August 13, 2010 Author Report Share Posted August 13, 2010 The CDI is brand new and the coil is good, I switched it out from my brothers bike which is running good so I know that is good. Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted August 13, 2010 Report Share Posted August 13, 2010 do you have a red winding ricky stator? I had a bike that just wouldnt pull up top due to a bad ricky Quote Link to comment Share on other sites More sharing options...
jst854 Posted August 14, 2010 Author Report Share Posted August 14, 2010 do you have a red winding ricky stator? I had a bike that just wouldnt pull up top due to a bad ricky The stator is stock and I am assuming it is good, I will swap it out for a know good one though. Quote Link to comment Share on other sites More sharing options...
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