Really Slow Yamaha Banshee Build

[maxpower49]

I bought a banshee project about three years ago and for the most part I have just been collecting parts, however I am finally getting fairly close and have enough to mostly get the engine assembled and take the first major step towards completion. I do have another banshee that is running as well as another quad so this one has just kinda been a slow project geared toward being a show quality build with nearly double the factory horsepower. Any way I snapped a few pictures of the engine build up and figured I would post them up and just make a little bit of a build log plus I'm sure people enjoy watching projects get built

A few details about the engine, I went with a Hot Rods 4mm Long rod stroker crankshaft, and a pair of Wiseco forged pistons, because of the added length of the connecting rods the port timing has been changed so I was going to send my old cylinders in for porting however I found a set of used cylinder with the porting that I was planning on having done and it included the pistons and the domes needed for the cylinder head so I purchased those instead, they have a Wildcard Racing aggressive dune port with the port timing adjusted for the crankshaft. I had the transmission modded as well by removing half of the ears on some of the gears to allow for a much smother engagement and I had a bearing added to the shift drum to make it move smother when shifting.

The cylinder head is a cool head domed head that allows me to change out the domes and either raise or lower the compression, the domes that I will be using will allow me to run 100 octane fuel and it also had to be custom cut for the extra stoke in the crankshaft because the pistons poke out of the bore by a slight amount.

I finished up assembly today and I am just waiting on a few more parts and the covers and I will have a complete engine ready to run, like the title says this is going to be a slow build, I have a decent stack of parts however there is always something minor forgotten and I am on somewhat of a budget so I just plan on taking my time and building this up properly.

 

[landuse]

Awesome!

 

[Flyinhillbilly]

There is nothing, and I mean nothing, In this world more fun than a worked banshee. I had one in my early 20's and wish now I had kept it.

 

[maxpower49]

There is nothing, and I mean nothing, In this world more fun than a worked banshee. I had one in my early 20's and wish now I had kept it.

I agree completely, I have one other with a few minor mods and it is pretty darn quick, I can't wait until I get this one going with nearly double the power

 

[maxpower49]

Messed with some small stuff waiting on a couple parts before I can get the engine assembled, but I checked the squish clearance for my domed head, should be between .045 and .055 of an inch and hit it perfectly centered at .050 and I installed the o-rings for the head and torqued it in place.

Once my intake and reed cages show up I will be able to leak down test the crankcase and once it passes that I will get the clutch side assembled and I will have a ready to run engine!

 

[maxpower49]

Had some parts show up that got lost in the mail coming from Canada, but bought some new clutch cushions that go in the basket, the ones in my basket were looking a little disfigured haha Once a few lock washers show up I will have the inside of the engine buttoned up and it is just on to a waiting game to get the cover that I want to make it look pretty.

 

[maxpower49]

Some minor progress, my shift shaft showed up and I was able to get that installed and the clutch basket bolted on, but on the bright side I finally received the paper work from New York state to say I legally and completely own my frame so now I can do some minor mods to the frame and get it powder coated with peace of mind! I have some new reeds on the way and once they show up I will be able to get the engine sealed up and build a leak down tester to check for leaks, if all is goes well and it passes I just need a couple minor parts and the engine is pretty much complete.

 

[maxpower49]

Well my new reeds showed up and I got them installed on the reed cages and ready for installation, ran into a small blockade, the billet one piece intake I am using needs two pairs of gaskets for the intake to the reed block as well as one to the reed cage to the cylinder the gasket kit I bought only came with two and I did not know I needed the extra set beforehand... :toetap05: Oh well a quick trip to the local parts store slash dealer and I will have two more gaskets by Friday. In the mean time I built up a new leak down tester for the larger carb boots and I am pretty much ready to test once I get the other gaskets.

 

[Bwdeaton]

I've never rode a banshee, or even seen one in person I'm pretty sure. Considering how many yamaha made, they're real **** expensive in my area. I've got other quads though.

 

[maxpower49]

I've never rode a banshee, or even seen one in person I'm pretty sure. Considering how many yamaha made, they're real **** expensive in my area. I've got other quads though.

It really depends on your area, here in New York people seem to want $3000 regardless of condition or mods as long as it runs, and I agree it is expensive, I have a buddy in Kentucky and he can pick up a running one for $1500-2000 depending on mods. I got lucky and picked up my basket case for $500 and have probably spent about $2000 so far over about 3 years getting up to the quality I want, I could have just tossed it together and left it pretty much stock but I guess I just want a high powered monster. Plus I have two other quads kicking around so they have kept me entertained as I slowly build this one up.

 

[maxpower49]

I picked up the two extra gaskets and tossed them in and torqued the intake to spec and thought I was ready to pressure test until I realized that I forgot spark plugs. But I had two spare plugs from a rider mower that threaded in and sealed so I tossed them in just for the leak down test. I sealed up the engine with the home built leak down tester and pumped it up to six pounds and after chasing down a couple leaks at the caps I was using on the exhaust ports I was able to get it to seal completely and I passed the leak down test! It held six pounds for over the minimum six minutes, that means that my engine should run nice and healthy with no air leaks.

 

[Poboy kartman]

Glad to hear you passed the leakdown test....but I bet you had crib notes scrawled up your sleeve! !!!

Carry on....

 

[maxpower49]

Glad to hear you passed the leakdown test....but I bet you had crib notes scrawled up your sleeve! !!!

Carry on....

I always have the service manual open with my nose burred in it, that is the only way I know any thing

 

[maxpower49]

Little bit of an update, I have been busy with work and waiting on parts mostly, but the pancake bearing showed up, banshees have a bit of an issues with the clutch rod welding itself to the clutch ball and there are a couple companies that make a fix for it that is basically a needle bearing that replaces the stock adjuster and allows things to spin smoothly and prevent welding. I also cut some tabs off of the frame, mostly ones that will not be used like the front plastic mounts (I will be running cut front plastic), the rear foot basket mount (I will be running some nerf bars that have a built in basket) and a mount for a control box that is nothing but a hassle on most banshee that I will not be using. It is one of those small things that just add up to make it look better and like I have said many times I am in no huge rush on this build so do once and do it right!

I have the clutch side pretty much all buttoned up and adjusted, I will be installing a new clutch when I am closer to running the engine but for now I have the old one in place for looks mostly. I am getting a high output stator for charging and I have an adjustable timing plate to mount it on once the stator shows up the engine is complete minus covers but it will be ready to run. I still need to smooth out where I cut the tabs, weld in a support or two and fix the hole where a foot peg ripped out, I will be getting some proper weld in bungs to fix it once and for all then it is off to powder coat for the frame and swing arm!

 

[maxpower49]

I'm still here and I have a mini update lol, it has been a while but I did mention it was going to be a slow build. Any way I have been in a strange spot, I am waiting on some parts and there is only one guy that sells them, I ordered a set from him and he said it would be five weeks until he could send me some So I talk to a buddy of mine that has a lathe and he said he could whip me some in a week or less, however that was about seven weeks ago...

I am pretty much stuck waiting on some parts that I need to weld to the frame before I powder coat it. So like I said I am in a strange spot, I have the money for the powder coat and parts however I just plain can not get the parts... Meanwhile I have has some other parts building up that need to go on after powder like new long travel front A-arms from Alba racing and an aluminium oversize radiator to help keep things cool.

And one more thing, I was thinking and I was going to have a bunch of small parts powder coated along with the frame however it added a decent amount of extra cost to the price, so I actually picked up an Eastwood home powder coating kit and figured I would just coat the smaller parts myself, it is slightly more expensive that it would cost to pay to have the parts powdered however I now have the ability to powder coat almost whatever I want whenever I want. However I am limited to whatever I can fit in a house sized oven so the frame will still be getting professionally powder coated, plus it also helps to guarantee that at least the frame will look good

 

[Joe-405]

Keep at it. And if you got any questions I'm sure I can assist.

This is the one I built and raced last season.............. went 4.80's in a 100 yards....

 

[maxpower49]

They are fun quads this is my second banshee build and they are addicting that's for sure haha. And thanks for the offer man help is always appreciated and I'm sure there will be a wall I run into somewhere that I need some help with.

 

[Bwdeaton]

I just got a banshee about a week ago, after saying I've never had one before. I just couldn't pass it up for the price. No plans for any high performance build or anything, just need to do a stock rebuild to get it running again. New wiseco pistons on the way and going to local place to get a crank that was swapped out for a stroker so they have a stock one for sale with 10 hours on it, saves a lot of money. Came with two motors worth of part and a real nice set of stock cylinders, also came with a new clutch and basket, and a cool head, but I need to get bigger domes to use it as I plan to do a build for mid-high grade pump gas. Anyway, heres some pics!

 

[maxpower49]

I just got a banshee about a week ago, after saying I've never had one before. I just couldn't pass it up for the price. No plans for any high performance build or anything, just need to do a stock rebuild to get it running again. New wiseco pistons on the way and going to local place to get a crank that was swapped out for a stroker so they have a stock one for sale with 10 hours on it, saves a lot of money. Came with two motors worth of part and a real nice set of stock cylinders, also came with a new clutch and basket, and a cool head, but I need to get bigger domes to use it as I plan to do a build for mid-high grade pump gas. Anyway, heres some pics!

Heck yeah! I started off saying it will be a mild build as well, next think I knew I was buying a stroker crank, then ported cylinders because they have to be ported to match the stroke, then high compression domes for 100ll, and well the horsepower keeps adding up along with the bill lol

One thing I might suggest especially if you are going to be upping the compression on a stock crank is to have the crank welded, they are just press fit from the factory and with too much compression or trying building massive power they have been know to rotate and come out of phase over time, I would ask the shop if they would be able to weld it for a decent price.

 

[Bwdeaton]

Heck yeah! I started off saying it will be a mild build as well, next think I knew I was buying a stroker crank, then ported cylinders because they have to be ported to match the stroke, then high compression domes for 100ll, and well the horsepower keeps adding up along with the bill lol

One thing I might suggest especially if you are going to be upping the compression on a stock crank is to have the crank welded, they are just press fit from the factory and with too much compression or trying building massive power they have been know to rotate and come out of phase over time, I would ask the shop if they would be able to weld it for a decent price.

Didn't have anything done to the crank. Bought a stock crank that has about 15 hours on it and was swapped for a stroker. Felt like everything was nice and smooth and good tolerance from my experience.
Put it together last night. New pistons and rings and went with 22cc domes so it still has factory compression ratio. Did the painting with duplicolor ceramic paint, which has held up pretty good for me on other projects. Looks great. Going into the frame tomorrow morning. Still have to get one new stud because one got crossthreaded, but still going to get it installed and get the stud tomorrow from machine shop.
This is first banshee, so i want to try it stock and see how a stock one performs before doing performance stuff.

Also noticed that i need a front sprocket, the one that came with it is missing a tooth!

Heres some pics from my phone