banshee1999

would it really be that bad though? I would have access to precision machinery and would get sleeves made by a sleeve company. I just don't understand how they are so much worse than cast cylinders. Would it be due to the very specific port timings needed for an engine to run well

what do you mean?

I am almost certain all banshee frames were painted from factory. the way I stripped mine was with a sandblaster, but I have heard of people getting them dipped in acid or something, usually powder coating companies have them. maybe you can pay them to just strip it for you? just an idea.

Since I am in university, I have access to CNC mills and lathes, as well as manual ones and I wanted to try and make a set of cylinders or a Monoblock. the only cylinders I have seen that are billet for banshee's are the old twister ones, but I can find almost no information on them. if anyone has and information or pictures of twister cylinders, or any billet cylinders, it would be greatly appreciated. Thanks in advance!

The vin is on the clutch side frame tube below the engine. there's no indication of another tube being welded in. sorry I don't know how to compress an image below 50 kb without making it impossible to actually see.

From my frame. I asked the local Yamaha dealership If they could run the VIN, and it apparently came back as a 1999, but it seems a bit odd that someone would do an A-arm to J-arm conversion. Maybe someone re-engraved the vin? but the vin seems to be factory, so I don't really know.

Alright, thanks skeeter

I do not think so, its just what came on my bike when I bought it and I just wanted to make sure it wouldn't hurt power.

My bad, I am new to this, first time owning a 2 stroke, just trying to figure things out.

Did you use an oil and fuel resistant gasket maker on the cases? If the gasket maker is disintegrating, it can cause a leak. If there is a crack or imperfection in the mating surfaces or something causing oil to leak through the case to the stud, you can just fill the hole with yamabond, but that could cause issues down the line; its better to get it welded and milled down to be even with the case.

I second that, mine had a leak in the carb boots due to cracking of the rubber, as well as the base gasket.

A few months ago, I bought a banshee sight unseen, which was probably my first problem, and only rode it for 3 days, each day something went wrong, and on the third day, I blew a base gasket and overheated the engine, melting the pistons to the cylinder walls. Anyway, I bought brand new Niche cylinders + head, Wiseco pistons, V Force reeds, and a hot rods crank. The old crank was probably fine; it was a Wiseco A1 crank, but it was at the upper limit for big-end connecting rod side clearance. This full backstory ties in with me knowing the owner of the Yamaha dealership near me, who said that porting was the way to really wake up a stock bore banshee. he said that he had his sent out to I think one of the sponsors on here, but his is also a big bore 520 or something. I am fairly mechanically inclined, as I have tinkered with things since I was a kid and am currently in school to become a mechanical engineer, so I decided to do my own very slight porting on the new cylinders. Porting is such an in-depth topic, so it really led me down a rabbit hole, which showed me that I really have no clue what I'm doing and that I really should not go crazy porting on these cylinders. I ended up coming across a video from Herr Jugs Racing called "Banshee porting 101 simple start" which is the video I followed much exactly. I raised the exhaust port roof about 2mm and widened the exhaust port by about 3mm. also cleaned up the intake port a little bit and knifed the divider a little bit. just wanted to come in here and show my results and get some feedback for if I ever do this again or if it will blow up immediately after building it.

I don’t fully remember before I took it all apart how it fit but it definitely fit together before, maybe not very tight though. I’m more worried about power loss than anything

I bought a banshee over the summer and it came with CPI pipes and fmf silencers and I was wondering if it would be worth it to go with a matching set, like getting CPI silencers or a full brand new exhaust system? I’ve heard that the fmf are too restrictive for the CPI pipes but I’d rather not spend money if it won’t make much of a difference.

So, I recently picked up my first banshee and promptly blew it up within 3 days of owning it. Anyway, that's not the point of this; I was checking out the VIN number on the frame, and it is JY43GGW003C248131. I have done some research, and it looks like it is a 03', but it confused me since it has J arms on it. I don't know if someone could have done an A-arm to J-arm conversion, but that really doesn't make sense to me since A-arms seem much better. also, it looks like the previous owner replaced one of the J-arms previously, as they do not match on both sides. not too sure if this will affect the riding of the bike and get new j arms, or if I should just leave it the way it is. thank you for any advice!