4stroke4lunch

After looking over all the carnage, I have discovered it was most likely the infamous BOOST BOTTLE that pulled the pin on the grenade. Although I can only blame my self for not thoroughly checking over the bike befor I ran the shit out of it. I only changed the tranny oil, plugs, cleaned the carbs and filters and ran it. I never even thought about airleaks. I am kicking my self now because the bike did sit for a few years. Also this is what the piston tops looked like both were about the same. Does that look normal?

It's from all those pussies on 4strokes shee was eating. Lol On the swing arm issue I don't want to go longer if anything ill keep it stock. I live in south fl witch in my mind sucks ass for riding. I grew up in the NJ pine barrens and I know a lot of cool very technical trails I use to ride with my 98 stock banshee and plan on taring that shit up with this beast. I have not ran a 90 hp banshee and I will take your word that it will be difficult to control, but I will try to tame the beast, or kiss a few trees trying. Lol

The crazy thing is I kicked the bike over and it started on 1 cylnder first kick and I road 1/2 mile to my truck.lol

I think one was pitted if i remember I'll wont be able to check till tuesday. Is that crank junk or can it be rapaired? The case i was going to try to repair my self I have a aluminum welder but dont want to take the chance on a new build.

sorry it took so long with the pics. Thanks finch for the help. Thats my 5$ spray can paint job.lol going to be a black on black bike does any one know where i can get a matt black rear fender and rad shroud?

Sorry about the pics, it says file is to big??? Never did a leakdown on the bike. How often should i do one, after every Ride? The only thing i ever did was shut it off with WOT mid ride and check the plugs to see if it was running ok. I was running avgas and yamalube at 32:1 went through 1 full and 3/4 of a 5.5 gal gas tank then it happened . I am starting to think air leak. The bike did sit for 3 years befor i got it. On tuesday I will look into that . Thanks for the the advice

My friend Marco at rocket ride cycles is getting it from a guy on the fl west coast. Not sure who but when he gets back tuesday I'll know. The guy came hightly recommended. Any info on setting up this 421 will be greatly appreciated. This is a list of things I have and ordered let me know if I'm on the right track. new case new 421 cub cylnders new hotrods 4mil welded/trued new fly weel- had to drill holes in old one to remove and broke the puller lol new stator wounded for dc with rectifier gona run a batt and 2 12v fans on the back of raditor new large raditor-havent decided witch one any suggestions? not sure if I have it but I'll get the bullet impeller Have pro desing cool head getting new domes Have 36mm keihin carbs with boost bottle dont know if ill keep it ? Have some sort of ajustable race ignition Have K&N pod filters Have lsr +2+1arms Have protapper bars Things to come over the next 2 months-need to save more cash. lol stock trans gona have to get modded will look in to camatv for that -1or -2 swing arm ? elka stage 5 front and back with link -thats going to hurt the pocket but rider confert is hight on the list antivibe stem and flex bars full skids six pack rack for more fuel going to build own front bumper to go with my custum front nose I built out of aluminum diamond plate good set of beadlock weels I have dg nerf but I want thoes pro pegs with heal gards Thanks for any input

I plan on rinning skid plates do they make them for my lsr +2+1 arms and a -1 or -2 if i get one? I plan on buying elka shocks front and back does anyone have their sunspension lik, and is it worth the money?

Has anyone ran a - 1 or -2 swing arm with a 421 or should i just stay with a stock one? no hills in south fl so i will be doing a lot of open trails and some tight ones time 2 time 3-4 gear kind of speeds

Thanks sprinklerman, will definitely be doing some trans mods. Common mods? Im not too much in to drag racing if that makes a diffrence on the mods i should get. On a diffrent subject I noticed the front tires kicks dirt/mud right at the pod filters sometimes, I was wondering if someone has done or heard of putting some kind of screen on the sides of the bike to deflect the dirt? Any info is greatly appreciated.

Thanks sprinklerman, will defentaly be modding the trans. Common trans mods to do? On a diffrent note The bike came with no front or rear fenders and i noticed the front tires kicks dirt/mud right at the pod filters. Has anyone done or heard of a screen that can be put on like a side cover to deflect most dirt and mud?

I am not worried about spending extra money to make it right. Ive spent 3600 on a new case, cub cylnders, hot rods 4mill crank, cpi pipes, and new domes for the cool head I have and other parts. I am going to spend more than that on suspension. I just dont want to get this thing togher and have tranny problems. To me relibality is worth every $. What is a cut trans? The guy selling me the parts said i'll have 93 hp what are recomended trans mods for that hp. Thanks again, still trying to load pics

Melted piston

I'm sorry i can not get pics to load off my iPhone for some reason I have some nice pics of the destruction lol.

The only thing I did was cleen the air filters. It sucked because I was getting back in to riding after not having a bike for 8 yrs. so now I am building a mad max 4stroke eater. I am going with a 421 because my step dad who raced enduros with a KTM 550 2 stroke always told me " there's no replacement for displacement" I've heard they have no bottom end would a ajustable timing plate give any more bottom end? Do I need tranny mods? Thanks for any info.

First off I am new to hq and I'd like to say this site is awesome. 3 months ago I traded a sig p220 svt 45 for a 03 banshee that had these mods lsr +2+1 arms, cool head, 36 mm carbs, boost bottle, v force 3's, some typ of ajustable ignition set to race mode, fmf gold series sst with power core 2 silencers, and had some crazy porting on stock bore, wiseco pistons, and ran on avgas.I ran the bike for a month 3-4 times a week. It out ran every thing I raced....... then one day in 4 gear power band BOOM. Melted piston in one cylinder, cracked cylinder, broken connecting rod, rod went through the case. I am rebuilding with a 421 cub, but I'd like to know how this could of happened so it won't on my new build? As for the old engin can the cylinder be resleaved and can the case be welded?