PassionRE

The reason I asked which side it was is because if your crank gets out of phase it will fire the right hand cylinder out of time and cause this. BUT since it is the left side, that rules that out. Its a little hard to tell with the pics, but it appears you have a classic case of detonation meltdown. Since your running good gas and the other side looks ok, that rules out fuel and compression ratio issues. The lack of four corner seizure, or from what I can see anyhow, rules out cooling system issues most likely. I would look closely for airleaks around the intakes, base gaskets, reed gaskets,L.H. crankseal,and also inspect the L.H. carb jets closely. Its almost a certainty that cylinder leaned out for one reason or another....Jim

Which side of the motor did that piston come from?...Jim

I had a 78' 750F with a 920 kit 12:1, Branch flowmetrics head ,and titanium valve train golden RC rods, smoothbores. Then got a black 79' DOHC 750F...man I loved that bike! Later had a supercharged 750 with Tracey body and flames and chrome.....It just whined and puuured down the road...those were the days..I would give anything to have that supercharger back now days. Built several Ray-Jay turbo ZI-R's with over 20 lbs boost with nitrous and water injection back when I was a Kawasaki wrench. Got to eyeball alot of Paul Gast work back then on H-2's and H-1's..thats really when I was just getting started. I was extremely lucky to work shoulder to shoulder with some of the best 2 stroke guys in the business...I was truely blessed and knew it....Jim

Remind me to send the "Gerth Daddy" stickers for the tank and fenders...Jim

Yeah, my kid has a new car, dirt bike, Jet ski,cell phone, credit card and more spending cash than 6 of his closest friends combined and is just crushed to get on the rider and mow the lawn. I was working at 11 yrs and saved enough for a SS Chevelle by the time I was 13. What the hell happened here?....Jim

Duece, I wasn't lucky enough to get the Elsinore when it first came out even though my parents ran the local Honda dealership at the time. But a few years later I did manage to get one that was set-up for flat track and had the original proto-type mono-shock that had been developed here in Tulsa and the guys that built it later sold the rights to Yamaha. Terribly crude with a monroe car shock absorber. I later upgraded it to a Fox shock and took the front end off a RM125 and mounted it up and had a pretty good bike although it was a "Frankenstein" ride for sure....Jim

70' Suzuki TS-50 "Gaucho"

Boonman, I run NO air filters!

If your car is equipped with an air-flow meter or mass air flow sensor it will probably compensate just fine for the additional flow. On Programmed PGM systems,with throttle position sensor and MAP sensor, the O2 sensor will most likely compensate for it...I dont see a problem....Jim

I can hardly wait till the weather warms up. Went out for a test run on my kid's ski today...what a rush...Jim

I guess you know that if you would just mount a pony-keg back there you wouldn't need that -2 arm on there....Jim

David is a top knotch guy and stands behind his products. I use NOSS heads exclusivly on all my high-end motors..Jim

Holeshot, my brother sent me that in a email a few years ago and I just laughed my ass off...that is some funny stuff. Got1Banshee, I can cut a few corners on your engine so you can get some counceling buddy...get a grip...withdrawl is a terrible thing, but your not alone. My kid a few months ago recorded a stroker motor I was jetting while I was rippin down the street full bore and put it on his cell phone. Now when he's not around when his phone rings I here this Shee just hauling ass through my living room..Jim

No offense taken, I was pretty sure that you had not seen my porting. And the post really was just to clear up the fact that my 12 ports dont have additional "boost" ports...Jim

Actually my 12 port cylinders are not equipped with "boost" ports. Boost ports generally refer to additional transfer ports located at the rear of the cylinders. A Banshee motor has more than enough "boost" as it is and personally I wish they didn't even have the ones they come with. My 12 ports are additional intake ports (finger ports)located on the left and right of the normal intake ports.These gases are redirected through window ports in the liners below the rear transfers at an angle and increased velocity torwards normal inflow gases. The result is an intake tract that has much more volume and maintains characteristics in low to mid rpm ranges of a high velocity low volume intake due to superior fuel atomization. They also allow the needed volume increases for increased rpm. These ports are not near the water jackets at all....Jim

You can gain much more usable power in every area going with a stroker over a big bore kit...Jim

Ball hones work good for de-glazing but wont give you a true indication of bore wear. You can have a totally distorted bore and the ball hone wont represent that after honing....Jim

I forgot to add that after you finish honing your cylinders, wash them extensively with hot soapy water(dishwashing soap works well for this). Then wipe the bore surfaces down quickly with paper towels soaked in motor oil. Do this several times until the towels come out clean with just the motor oil on them. This will indicate that all the honing stone material has been removed from your crosshatch. Do not wait to wipe them out with the towels very long after removing them from the water/soap solution or rust will form almost immediately...Jim

Set you speed on the drill at a medium rate and make several passes with the hone at a constant rate up and down. Once you've determined that the cylinder is somewhat true(this will be indicated by places where the hone is not touching). NOTE:It would be considered normal for the hone not to touch around the intakes and in some areas above the exhaust ports on a somewhat used engine. Its up to you if you want to hone it more in order to clean up these areas, but be warned you may exceed safe clearances and expose your engine to increased possibility to piston skirt breakage. Next, slow the drill down to a rather slow rate of speed and increase the rate at which you are moving the drill up and down. This will give you the crosshatch your looking for. On your very last pass, stop the drill at the bottom of the bore nearest base gasket area. Pull the hone out using your fingers to depress the fingers of the hone while removing to avoid scratches in a verticle direction....Jim

Your not going to lose power running a cool head with correct domes with any pipe application. If you fall prey to the horsepower bug later down the road, and you will, steer clear from the T-6 and go with a T-5 or CPI. And contrary to popular belief, the CPI's are a pretty damn good torque pipe with the right porting combo regardless of what they were originally designed for.....Jim

If your looking for a good MX/TRAIL machine that does both very well, go with a mild port job and a set of PT-MIDS. You can get alot more power in other routes, but keeping trail manners in mind, its a combo thats hard to beat. You'll end up with a bike that isn't explosive but can hold its own in tight situations...Jim

Compression is a good thing, but not at the cost of proper squish clearance. You best check your squish clearance and hope for at least .028" You cant just go and cut what feels good with the variety of pistons, base ,and head gaskets that are available out there and expect a reliable engine without doing the the dirty work..IMO... Oh, and as far as "how much is too much?"..LMAO...depends on who you ask......Jim

On pistons with existing window ports, increasing the size to match porting produces minimal results at best. Using die grinders, dremels etc., create ultra high frequency's that will cause micro fractures throughout the piston skirt and will shell out your motor when you least expect it. The only way to properly do this job is with a face mill. Dont push your luck...Jim

The dollar to horsepower ratio isn't too attractive going from 66 to 68 mm on that engine. I suggest you stay with the smaller pistons and take the money you saved and put it torwards quality porting work...Jim

There are definately limits on porting for a 350 platform and then going to a stroker later. Get with your builder before hand and let thim know this if you want to run a stroker later.....Jim