riderboy Posted April 23, 2007 Report Posted April 23, 2007 (edited) Just got back form the dunes. Had a a great time. Banshee ran great, but kept having a problem with the spark plugs vibrating loose and also had one of the plugs come apart where the ceramic goes into the bottom metal part. Almost like it is detonating or something. But engine sounded great. Wondering if any one had any idea why this kept happening? Banshee has a 68mm cub cyl., cool head with 20cc domes, 33mm carbs, CPI inframe pipes, timing plate set at +4, dyna ignition set on setting 3 on the programmer, and lightened flywheel. Running on 91 octane gas mixed 32 to 1. I have ridden the quad about 4 times since I got it put together and never had any problem before. This was the first time riding it at Little Sahara doing quite a bit of drag racing. Any ideas would be a great help. Edited April 23, 2007 by riderboy Quote
onebanshee Posted April 23, 2007 Report Posted April 23, 2007 I had the same thing happen to my quad a lot, sometimes the spark plug would go flying out, it would scare the shit out of me, it kinda sounded like blowin the engine, but then i would look down and see the spark plug hanging by the wire. WTF? anybody? Quote
MFIC Posted April 23, 2007 Report Posted April 23, 2007 Just got back form the dunes. Had a a great time. Banshee ran great, but kept having a problem with the spark plugs vibrating loose and also had one of the plugs come apart where the ceramic goes into the bottom metal part. Almost like it is detonating or something. But engine sounded great. Wondering if any one had any idea why this kept happening? Banshee has a 68mm cub cyl., cool head with 20cc domes, 33mm carbs, CPI inframe pipes, timing plate set at +4, dyna ignition set on setting 3 on the programmer, and lightened flywheel. Running on 91 octane gas mixed 32 to 1. I have ridden the quad about 4 times since I got it put together and never had any problem before. This was the first time riding it at Little Sahara doing quite a bit of drag racing. Any ideas would be a great help. "timing plate set at +4, dyna ignition set on setting 3 on the programmer" = about +10 timing on 91 octane. Your detonating and rattling the plugs out. Quote
dajogejr Posted April 23, 2007 Report Posted April 23, 2007 "timing plate set at +4, dyna ignition set on setting 3 on the programmer" = about +10 timing on 91 octane. Your detonating and rattling the plugs out. Yep, plugs backing out are detonating or worn out threads on the head. It's not going to back out too many more times, it will blow up soon. Get race gas... Quote
sheefreak Posted April 23, 2007 Report Posted April 23, 2007 Yep, plugs backing out are detonating or worn out threads on the head. It's not going to back out too many more times, it will blow up soon. Get race gas... 3rd. W/ that much timing and 20cc domes, you are definately detonating. Especially since you said you have plugs parting out. Like Dave said, it will not give you tell tail signs too much longer.... Quote
badassbanshee479 Posted April 23, 2007 Report Posted April 23, 2007 better back the timing down and or start running race gas!! You are riding a ticking time bomb right now! Quote
Snopczynski Posted April 23, 2007 Report Posted April 23, 2007 If your bike is pinging or detonating it will loosen the spark plugs up. What compression and what octane fuel are you running? Quote
Bansh-eman Posted April 23, 2007 Report Posted April 23, 2007 (edited) If your bike is pinging or detonating it will loosen the spark plugs up. What compression and what octane fuel are you running? his first post timing plate set at +4, dyna ignition set on setting 3 on the programmer, Running on 91 octane gas mixed 32 to 1. im not for sure but i want to say curve 3 advances your timing at its max like 15-20 degrees... then backs off .. you might be able to findit on thier site... for sure you need to bump up that octane... Edited April 23, 2007 by Bansh-eman Quote
dajogejr Posted April 23, 2007 Report Posted April 23, 2007 Curve 3 hits 22 degrees early, then tapers off pretty quickly. I used +8 on the plate, curve 3 on my dyna...and had 185PSI. But...I also ran 110 race gas. Quote
jbooker82 Posted April 24, 2007 Report Posted April 24, 2007 :biggrin: You need a spark plug lock from Trinity :biggrin: Just messing. If you did have a spark plug lock then you wouldnt even have known something was wrong until it didnt run any more. Quote
riderboy Posted April 25, 2007 Author Report Posted April 25, 2007 I finally got a chance to check the compression. It only has 145psi on each side. I wouldn't think that that would be high enough to have to use race gas. I am wondering if it's something to do with th domes. They are oversized domes made to fit a stock size cool head. Any more ideas? Thanks for the advice so far. I really don't want to blow it up. Quote
cam2 Posted April 25, 2007 Report Posted April 25, 2007 I finally got a chance to check the compression. It only has 145psi on each side. I wouldn't think that that would be high enough to have to use race gas. I am wondering if it's something to do with th domes. They are oversized domes made to fit a stock size cool head. Any more ideas? Thanks for the advice so far. I really don't want to blow it up. yeah, all the timing that you are using can cause a detonation problem alone without high compression. with what dave is saying that is a butt load of advanced timing, especially for 91 octane. Quote
riderboy Posted April 25, 2007 Author Report Posted April 25, 2007 Thanks for all the advice. I will try race gas and see what happens. Do you think that 91 and 110 mixed 50/50 would be enough? Quote
dajogejr Posted April 25, 2007 Report Posted April 25, 2007 What kind of compression gauge did you use? Name brand, or auto store cheapy? (It makes a HUGE difference) Did the thread reach on the compression gauge screw into the head as far as a spark plug does? Normally they don't...that's a few more PSI. If you plan on running that much timing, I'd run straight race gas. At 145PSI and a moderate amount of timing...say curve 3 on the dyna and 0 on the plate...or 4 to 7 on the plate and stock curve on the Dyna...you could probably mix 50/50. Honestly, if you like the way it runs with that much timing, just buy 110 octane, don't mix it...and leave it in there. Quote
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