TurboBanshee420 Posted August 16, 2009 Report Posted August 16, 2009 hey... Got a set of shearers on my 421 cub...38PWM's, upp intakes.... good clean-up on the ports. No timing changes. stock timing plate for ignition. 165 mains EEG needles 52 pilots going out in a minute to ride and see how it feels. hey question...chariot bowls...They fit PWM carbs? peeps say they are the same bowls. Space is tight already. You guys have a problem with having enough room for bowls and stuff? I had to cock the carbs a bit to get them to fit good in there. discuss....anything about the topic, chime in! Quote
TurboBanshee420 Posted August 16, 2009 Author Report Posted August 16, 2009 just got back from my ride.....started out ok... plugs were clean on the chop so I went to 168 mains. I had a fat spot across 1/3 > 2/3 throttle so I dropped the needle to 2nd from the top. It got better but the needles are wrong. They have too fast of a cut on them. I will try the CEL needles as everyone is running them. one important thing though.... plugs are still jumping out of the head. i'm going to check the squish and see if i need more chamber volume or a thicker base gasket. tonight is 65* and about 80% humidity. I'm around 600-800 ft elev...jfyi anyone....one the detenation topic? or needle choice? Quote
dajogejr Posted August 16, 2009 Report Posted August 16, 2009 Need to know your UCCR, your squish and cranking compression. Cubs love fuel and timing, but if you're backing plugs out...gotta fix that problem first. You're leak down tested the motor, right? Quote
TurboBanshee420 Posted August 16, 2009 Author Report Posted August 16, 2009 yes, she's no leaker.... I'll get the other info when i have a few minutes to wrench on it. I think the squish is too tight. The base gasket I used was a metal core foamish rubber gasket that was supplied. It was pretty thin! I've never used one like it before. I probably should've used the paper gasket from my kit instead. Quote
rubberneck Posted August 17, 2009 Report Posted August 17, 2009 Did you put race gas in or are you still running the 21 cc domes with pump gas. If so, i dont give a shit what your squish or jetting is its gonna rattle the plugs Quote
TurboBanshee420 Posted August 17, 2009 Author Report Posted August 17, 2009 I have yet to buy race fuel, but I will only run the banshee again with a tank full of the purple stuff..... Pump gas around here sucks balls anyways. I'm planning on pulling the motor back out this week and putting it on the bench for some review, cause I have a feeling my squish is in the .030's....or low .040's.... I would like to see .050 or better. That will probably mean I'll be pulling that base gasket out and using the paper gaskets I got from a&s. Or I'd like to find a copper gasket if they are still made. They used to sell them in different thinkness's. I'm also planning on doing some shift mods, and putting another washer on my lockout weights. I am probably going to buy some 24cc domes too. I like the very bottom end power for the small trails and putting around, but not by sacrificing some topend and having to buy race fuel all the time. I was thinking about retarding the timing some, but that really isn't the piont is it. Why would I want a cub with -4* or -6* retarded timing. So I'm going to just shoot for 150psi cranking compression. That will put me right where I want to be. then I can give her some timing and see how she eats. Quote
dajogejr Posted August 17, 2009 Report Posted August 17, 2009 I'm curious as to why you asked all the questions then in a few post later answered them all... 24cc domes with a mid to high 40's squish will get you running on pump fuel. If you start stacking the base gaskets, you need to degree the motor in for proper port timing. More base gasket is one way, having a dome/head properly machined for the piston angle and deck height is another. Cranking compression...does not give you octane requirements. It's a triple ported motor with drag port timings, your cranking compression will be lower due to that alone. You have the tools and knowledge, measure your UCCR for your fuel requirements, don't rely on squish and cranking compression. I can also tell you that motor will run like shit with retarded timing. Setup properly, there's no reason you can't put 4-6 degrees of advance on there and run pump gas. Good luck getting a lot of bottom end out of a cub for trails but keeping the screaming top end. Like I said before, you can take a top fuel car to the grocery store, but there are better ways.... Quote
TurboBanshee420 Posted August 17, 2009 Author Report Posted August 17, 2009 I'm curious as to why you asked all the questions then in a few post later answered them all... huh.gif Been reading....didn't get anyones answers still on a few of my questions. When someone else wants answers and searches my threads....they will get them, instead of more questions as to why someone would do this, like what commonly happens to most threads here on the HQ. Seems to have plenty of grunt off idle.... maybe my topfueler has enough room for groceries after all. I guess I don't clearify my words as best as you need them to understand me all the time daj... I should take some video of the trails I ride, so you can understand what it is I'm doing here with this bike. I'm wondering why you told me to buy 21cc domes for pump gas....I've been reading a few topics, and noone seems to be able to get away with that unless they are at 2500+ft of elevation and have a .050 or higher squish. Is this right? Quote
dajogejr Posted August 17, 2009 Report Posted August 17, 2009 Did I actually tell you to buy 21cc for pump gas? If so...I was unaware or not clear it was a 4 mil stroker.... You said small trails and putting around. To me...that's an absolute waste of a cub, any cub. Obviously pics and vids help...so maybe my definition of small trails and putting around differs from yours....or I'd hope so. Keep in mind my definition in Michigan of small trails are trails barely wide enough to squeeze your quad through between two trees, while managing 2-3 foot whoops. In that scenario...80 HP does no good... On your last statement in general...probably yes. Again, UCCR and timing dictate octane requirements... Quote
TurboBanshee420 Posted August 17, 2009 Author Report Posted August 17, 2009 http://bansheehq.com/forums/index.php?show...e+size+pump+gas Yeah I guess I'll just grab some bigger domes and not worry about it. small trails mean the connecting trails between railbeds...roughly car wide. railbeds are 2-3 quads wide and very fast.1' whoops in some areas, but long frequecy from the sleds in the winter. Quote
dajogejr Posted August 17, 2009 Report Posted August 17, 2009 I misread/misunderstood that...sorry... I missed 421! You can get 30cc domes but if the squish is too tight you're still gonna rattle plugs. Quote
sheefreak Posted August 17, 2009 Report Posted August 17, 2009 You mentioned A&S...did you buy this setup from Dan, or just the gaskets? Quote
ts3232 Posted September 22, 2009 Report Posted September 22, 2009 I am going to add my 2 cents since I had the same problem and I fixed it. The problem with the spark rattling out is an issue with the jetting. I have the same issue and the only way I have been able to fix it is by jetting it rich. Once I jet it rich the problem goes away. My current set up is as follows. 421 Cub, 20cc domes, +4 timing, Hemi Head, Pingle, 34MM Pjs. My Jetting is as follows 50 pilot, 165 mains, and DGK neddle. I use VP MS109 mixed 50/50 with 91 Pump. Note at 160 main the plugs come out when I place the engine on a load (dunes or drag). At 165 I have no issue. With this setup it boggs down a bit. I am thinking of changing the DGK needle to the CGL in order to lean it out at the 1/8 - 3/4 range to see what it does. Quote
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