gotta_goatsfast

IBEW?

Quite the ego for a mostly stock banshee! By "tuning a banshee" do you mean dyno/track testing components that compliment each other? Set the suspension and gearing up to match the type of terrain or track in which this banshee will perform? Build a motor that delivers a power curve to take advantage of the type of riding you do? Or maybe you just mean dialing in the correct jets and needles/position for the carburetors along with dialing in the correct timing advance? Because most of the members here are capable of performing this basic task required to operate a banshee to its fullest.

What worries me, is even if you TIG the hole (which requires a SLOW heat up and cool down time) the person probably hacked the cylinders beyond any reasonable performance. It probably runs like shit because he didn't know where to take material out and where to leave it. Sounds like he just hogged it all open!

First, go out and remove the carb bowl. Find out what jets are installed. Then, hop back on here with your findings (along with trouble symptoms) and we'll help you order the correct jets.

Suter's Speed Shop in Madison if you REALLY do not want to do this yourself. The process is suprisingly simple. Are you running a 2 into 1 manifold with a single 38mm PWK or twin 38mm pwks?

I ride a 421 serval and it absolutely pulls away from all the 4 strokes and bolt on banshees that I ride with (anything from black diamond trails to hair scrambles). For you, I would suggest you save some cash. Pick up a 4 mil crank and some stock bore/port cylinders. Send them out for a woods or MX style port. A stroked "low-mid" port motor will be your best bet in tight trails. Since you keep stressing tight trails and woods, your first concern should be the suspension/tires/brakes. This will ultimately make you faster than any motor will in these conditions.

dumbass

Is this from experience? Have you any real world experience with a 421 serval equipped with T5s? Because you would probably note that those who have tried the T5s (seat time and dyno time) all agree that you are leaving a substantial amount of USABLE power on the table compared to other pipes. In fact, my R2s with this engine will come into the powerband sooner than a stock port T5 single carbed bike.

What did you set your tolerance between the pickup coil and the flywheel magnet? Setting it real close (ten thousanths or less) will allow the flywheel to rotate by hand without contacting the pickup coil, but at 7000-10000+rpm the centrifugal force will "spread" or dialate the flywheel (because metal is maleable). I use a 0.024" feeler gauge to set mine. Still picks up a quality signal but gives a little wiggle room. If this is not the case, you may have a tweaked crankshaft or out of balance flywheel. Both will "flex" and become more "out of round" the higher the rpm that it is spinning.

The real power is in the camshaft profile...

I love bubble wrap. If you plan on using peanuts, please seal the pipes off so peanuts can't sneak inside the expansion chamber. I recieved a set of pipes that were packaged very well but had a few peanuts inside. Took me quite a while to get them out. lol

My 421 really doesn't consume any more fuel than it did stock when just cruising around riding with the wife (she's kind of pokey). But if I'm in a race or riding advanced trails with expert riders then its no problem for me to suck down 5 gallons of fuel in 3 hours. But if all you do is trail, I REALLY suggest you do something with your suspension first. A 421 in a race or Black diamond trails is still a handful with quality aftermarket suspension, I'd never want to ride on the stock stuff.

Yep, if it means waiting another month to gather the difference in cash, its WELL worth it. I'm just south of Madison, where do you ride?

I bet he drives a civic.

Works steelers set up for +2 arms and your weight will be much better than YFZ shocks.

Phelps, quick screwing around with your wompus. What that cougar needs is a long-rod.

I have been in talk with Works shocks (I have PEPs, but Matt suggested to go through WORKS to purchase replacement springs). I'm looking at </=$90 per main spring. For roughly $180 I can respring my front shocks and still retain the top notch internals that Matt has provided. I figured its my best bet since I know the history of all parts I'm dealing with, not someone else's potential problems. lol Just giving you a quickie of my experience. The advice is worth every penny you paid for it!

Both have unique styles (along with countless other top notch porters who sponsor this website). You will always get positive feedback from anyone who replies, but your best bet is to call and talk to each sponsor who you're interested in. Who ever you "click" with, or just feel is the better one is who you should go with. They are ALL honest and straight up with you. While they might not be the cheapest, they are more than worth the money. All have a high reputation for customer service and technical help. Your best bet is to contact a few and go with who ever you feel most comfortable with. But none will steer you wrong!

If you already have money into the shocks and know their history, why not just purchase a lighter main spring?

Plug chops get you close (you can find the procedure in the stickies). But once you get familiar just jet by feel. I used to chop my plugs but once you learn how your engine speaks to you, you can just jet it by feel and instinct.

I'm Bubbles

A-arms, entry level shocks (works dual rates or econo elkas) send out your rear shock to SoCal suspension, upgrade your wheels/tires.

You sir, have a message.

Sound terrible how? Mine have a slight "whine" or "howl" from off idle to about 4000rpm but nothing that turns heads. The exhaust and intake usually overpower said whine anyway.

No reason to mix Klotz @ 20:1 (even for break in). When breaking your motor in, you really don't need any more oil in the tank than you normally would (unless you're running 50:1 or more, then I understand). I think your detonation issue is because of a lean condition. First do a leakdown test to ensure you're still working with a solid motor. Then go a little easier on the oil. You're detonation could be result of a lean condition because there is a LOT of oil displacing the fuel. Therefore you are not getting the required fuel into the cylinder. Klotz burns fairly clean, so there shouldn't be an obnoxious amount of smoke if jetted correctly.