THE358BANSH Posted January 6, 2009 Report Share Posted January 6, 2009 Well guys, I took my toy over to Janssen tonight to play on their dyno. Specs are below. Warmed it up, changed the oil, filled with some fuel, and gave her hell. The BR8ES were gapped at .028", mixed 32:1 with Amsoil Dominator/93 octane pump fuel. It was a little lazy from 1/4 to 3/4, and in the upper range, 7-9k, it broke up extremly bad. With the wierd misfires, the motor revved really smooth to 6-7k, then fell on it's face breaking up with a few little puffs of black out the pipes and tried to climb to 9k. I went down on the needle, upped the main to a 235, and tightened the gap to .018"(shot in the dark). She ran much smoother, all the way through the rpm range and we cut the pull at 10k with only 2 wierd puffs at the end. Played with needle and pilot stuff for awhile, and then came back to WOT long pulls. I looked at the plugs, and they were hairline lean for my liking, so we drilled a jet to approximatley 245 main. Power fell off by about 1.5 in the top, which I was expecting, so I tossed a 238 back in for the rest of the session. I still am having troubles with the intermittent misfire(puffs) though. So far I have checked/changed, Plug wires-Had MSD 8.5mm Superconductor, went to a stock style copper core, didn't make that much of a difference. Swapped side just to check, no different results. Fuel delivery-Eliminated the petcock/tank with an IV style gravity tank, first two pulls were damn clean(best numbers so far i think), on the third the misfire returned, maybe sucking the bowl dry but that doesn't make much sense, or maybe just coincidence? Spark-Hooked up an inductive light and watched it when I had the problem, still had spark to my eye when the misfire occured. Plugs-I was using BR8ES most of the night, tried a non-resistor B8ES in combo with the IV fuel tank at the end, results same as two lines above. So guess my questions are, Are any of you guys having to run such a small plug gap to combat major misfiring in the topend? I have never had a bowl run dry on me before, and I imagine it to be like hitting the kill switch wide open? Offer up any other ideas, I'm open to suggestions... I'm going to go through my harness and check for clean grounds/electrical issues tomorrow night, give it a good once over to see if I can find anything out of the ordinary and report back. 385cc 4mil stroke 65mm bore 4mil play port by FAST Cases match ported 21cc domes by Noss machine at 175psi<-----Does that seem a little high to you? Vforce3s Graydon style intake 39mil PWK, 238 main,EEG needle third clip,62 pilot Huge ass K&N with a drywear Stock coil with factory style copper core wires Plugs gapped to .018" Timing plate set a 0 degrees for now Ricky stator 200watt<-----Seems a lot of discussion about these lately, anyone have a stocker laying around the want to give me? Quote Link to comment Share on other sites More sharing options...
F.T.W. Banshee Posted January 6, 2009 Report Share Posted January 6, 2009 I had a problem like that on top end. I changed the spark plug caps and it cleared right up. Might not be it but plug caps are cheap. Quote Link to comment Share on other sites More sharing options...
2001Stroker Posted January 6, 2009 Report Share Posted January 6, 2009 Mine was breaking up like that too. Turned out, it was the carbs were outta sync. Just a thought. Quote Link to comment Share on other sites More sharing options...
THE358BANSH Posted January 6, 2009 Author Report Share Posted January 6, 2009 I had a problem like that on top end. I changed the spark plug caps and it cleared right up. Might not be it but plug caps are cheap. That was one of the first things I tried after I noticed how much better the quad ran with the way smaller plug gaq, didn't seem to make a noticeable difference. Mine was breaking up like that too. Turned out, it was the carbs were outta sync. Just a thought. I only have one carb? Quote Link to comment Share on other sites More sharing options...
Snopczynski Posted January 6, 2009 Report Share Posted January 6, 2009 Ok first, I need to know what pipes your running so I know where your pull should end. 2nd, your carb is too big for your setup. All your jets numbers and needle are way too big. I did a single on a JSD 4 mill with stock cylinders, pt mids, and vforce reeds at a 35mm pwk, eej needle, 200 main jet, and 45 pilot jet. That bike would try and rip your arms out of the sockets. I am a little confused as to why you have all this mid-top stuff done with a 2 into 1 carb on it? 3rd, you may have an electrical issue like a pickup problem, melted harness, or cracked flywheel magnets. Dome size is null because your domes were machined. You are not running high enough octane for 175 psi compression though. You need to be at 100 octane or more. Black smoke is a seen of the bike running rich. Quote Link to comment Share on other sites More sharing options...
THE358BANSH Posted January 7, 2009 Author Report Share Posted January 7, 2009 Ok first, I need to know what pipes your running so I know where your pull should end. 2nd, your carb is too big for your setup. All your jets numbers and needle are way too big. I did a single on a JSD 4 mill with stock cylinders, pt mids, and vforce reeds at a 35mm pwk, eej needle, 200 main jet, and 45 pilot jet. That bike would try and rip your arms out of the sockets. I am a little confused as to why you have all this mid-top stuff done with a 2 into 1 carb on it? 3rd, you may have an electrical issue like a pickup problem, melted harness, or cracked flywheel magnets. Dome size is null because your domes were machined. You are not running high enough octane for 175 psi compression though. You need to be at 100 octane or more. Black smoke is a seen of the bike running rich. I knew I forgot something when I made that list, Toomey T5s I know that the carb is too big. That is the only reason why I can justify such a large jet and getting the plug readings that I did. To make some reason, large carb is going to equal a lower velocity which will pull less fuel therefore needing the larger than normal jet. Just referencing general carb theory there though... The carb actually came on the bike when I bought it, and it ran well, but nothing crazy. I have been contemplating going to a dual setup in the spring, and mainly just wanted to see how it would perform. I went through the harness tonight, added some star washers on the grounds and then got to my flywheel/stator. I had a local machinist lighten it a few years back, and he must have gone a little too far. I don't know why it came apart just now, maybe the weight of the magnets fatigued the thin metal or something. Just a few chunks of magnets/metal disappeared off the inside of the flywheel, so that is going to be prime suspect number one for now. How many kick are you guys ending a compression check after? I have yet to find a definate answer for the two stroke stuff... Thanks guys, Evan Quote Link to comment Share on other sites More sharing options...
Snopczynski Posted January 7, 2009 Report Share Posted January 7, 2009 warm it up , then kick it 11-15 times. Should stop going up, and should have the correct reading. Your motor should top out around 10,000 rpm with t5's on it and a low exhaust port. A 245 main jet is 9 full sizes above where I put that ported stock cylinder 4mill with the pwk 35. Thats like the difference between running twin 35mm pwk and a single on a banshee. Seems very unlikely you would need a mainjet that big. Quote Link to comment Share on other sites More sharing options...
THE358BANSH Posted January 7, 2009 Author Report Share Posted January 7, 2009 Thanks for the info, I'm going to go do a compression test again to see where I sit and go from there... Quote Link to comment Share on other sites More sharing options...
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