www.b50.org

Shawn_Mc

Hi Remember the oif 71 B25T/SS crankcases are essentially the same casting as the B50 but with different machining carried out. So it is possible to convert a set of B25 crankcases to B50, although there is a fair amount of work required. The crankcase throat of a oif b25 has enough meat to take a ...

Shawn_Mc

Have them Cerakoted. It's insanely tough and doesn't build up as much as powder does. You may want to fit the spokes first and see if you need to chase that hole a touch first. That way you wont have to drill your new coating. Ok thanks, do you know somewhere local that does this? I do. Juggernaugh...

Shawn_Mc

I don't know the answer to any of this but what cc would that end up being if it is possible. I'm pretty sure there is a 280 kit available. 334.5cc Big bore does a couple things for you. in addition to the displacement, it unshrouds the intake valve by moving the curtain away from the cylinder side...

Shawn_Mc

Has anyone done this? (Post 71', 3/4" bushing type) The base circle and lifts appear to be very similar, it's just a lot more duration. And is it possible to get a sleeve in there that will carry a 78mm piston? I'm aware that this isn't a bolt on...Just wondering how much meat is in the jug. Could i...

Shawn_Mc

Have them Cerakoted.

It's insanely tough and doesn't build up as much as powder does.

You may want to fit the spokes first and see if you need to chase that hole a touch first. That way you wont have to drill your new coating.

Shawn_Mc

I got a brand new 928 Premier from UnitSingles. It was about 30 bucks more than the parts to completely rebuild the 928 my B25 came with. My old Beezer starts first or second kick every time. I was originally going to put the Mikuni VM28 on it because Ive got a TON of experience with Mikunis and Kei...

Shawn_Mc

Is the PES part like the MX piece? I cant find it anywhere on the Web. If you go to this page, and do a search (Ctrl + F) for "Kickstart lever" you should get 8 results, included is this for the B50 and there are some with splined shafts (splined quadrant needed, but then you can use a variety of j...

Shawn_Mc

Seems like the stocker just sticks out way to fa, no need for all that clearance. Could almost be a straight arm! It could. The real issue is where it's indexed on the shaft and the fact that you cant change were it's placed because they used that wedge pin instead of a spline. They saved some mone...

Shawn_Mc

There's a Trials unit on BSA Unit Singles. He lists the MX part too, but none in stock. The trials part looks quite a bit longer. It's pretty expensive, but I really dont see an alternative... The stock kicker location is horrific. I cant believe I ever rode it as hard as I did as a kid, like that. ...

Shawn_Mc

Does anyone make a kick lever that actually folds out of the way? The kicker on my 71' B25 literally sits right in the path to the foot peg. I'm not opposed to breaking out the torch and reshaping it, but is it cast iron? Can I actually bend the thing without having it shatter or something (assuming...

Shawn_Mc

I just put RaceTech emulators in my B25 yesterday. All you need is a copper washer beneath the Allen bolt. That washer is just a seal. Why they did it that way, was is too smart by half.

Shawn_Mc

Here's how the damping rods work. This drawing is fairly generic, but pretty much, everything is there and applies.

https://www.racetech.com/page/title/Emu ... hey%20Work

Shawn_Mc

Buying some PTFE washers from https://www.ebay.co.uk/itm/Bespoke-Custom-PTFE-Teflon-Washers-1-5mm-thick-various-sizes-available-to-80mm/302592678775?ssPageName=STRK%3AMEBIDX%3AIT&var=601431743100&_trksid=p2057872.m2749.l2649 These are to fit some Koni 76 series dampers where the iron sealing rings ...

Shawn_Mc

Hi I have three points to make on this subject. I comment based on research I have done in getting to a similar point as the original poster here. One is that I tried to find an off the shelf solution to the o ring issue without luck. Eventually I bit the bullet and bought a set of ptfe seals from ...

Shawn_Mc

The stanchions I got were the heavy duty parts from the UK. I had to wash the cosmoline off/out of them and they were pretty good inside. Those phonelic parts probably work pretty good, but at $33 American, then being shipped to the US...YIKES...Gotta be a better way. I'll probably make a pair out o...

Shawn_Mc

RaceTech makes a teflon one, and they're a 20 minute drive from where I am, but dropping $20 a piece for glorified orings..I cant do it. It's the principal of the thing.

Shawn_Mc

I don't know if I understood your query well, but you must keep in mind the fork suspension snicking, with the springs loaded, this changes the rake. you can find a lot of information about this in the books of tony foale books But that isnt the way things get setup on the drawing. Normal suspensio...

Shawn_Mc

Besides Racetech, does someone offer a better, slicker option piston ring for the damper rods? I cant find it anywhere. Ive got a Gold Valve emulator coming for the fork, but I dont want to deal with those sticky OEM orings. Mine are brand new, but man, smooth, they arent.

Shawn_Mc

That snail adjuster was probably a result of the night terrors left over from the Titanium frame and Swing arm attempts of factory BSA for the Factory race bike. The swing arm flexed so much they couldn't keep the chain on.

Shawn_Mc

minetymenace wrote: ↑Wed Mar 25, 2020 10:28 pm Poll added....just for fun

300 miles of Motocross is a LONG TIME

Shawn_Mc

Well, I'm not relying on the silicone to seal. That's what the foil is for, The silicone is just to give the foil more body. I've got another idea that is far more work, but it'll be bullet proof for when / if this fails in short order. I've seen this method work for an actual head gasket, but we'll...

Shawn_Mc

That should work, but there will be oil thrown off the flywheel which may fill the breather up with oil. I am using the tach port on my TR25 race bike as seen here: Breather on TR25.jpg The O2 Sensor you got there seems pretty close to the head. Is there a specific reason for that? Because it is al...

Shawn_Mc

Little more here, little more there.

Shawn_Mc

Ok, this has been bugging me for 30+ plus years maybe... My dad made a couple suggestions...they didn't work yada yada Here's what I did: I took a 12 in long strip of Aluminum foil 1 1/2 inches wide. I spread a teeny bit of silicone on the header, wrapped the header with the foil leaving 3/4s of an ...

Shawn_Mc

I just took out the points. Left Everything else. Made a plug for wire.

Shawn_Mc

Trevor, can you post a link the Podtronics ignitions please. Paul. Now I'm curious. Why the dislike of the Electrex? You're the second or third person I've seen try to steer someone away from the Electrex unit. Why marry yourself to another magnetic pick up (assuming that's the route) wedged into t...

Shawn_Mc

I've got another question Why does everybody (including BSA) put the brake backing plate on the right side? Doing that give the brake cable an unnatural path to the lever. I looked at that and thought "that's just silly". The way I mounted it, on the left side (and Ive seen a couple others did it th...

Shawn_Mc

koncretekid wrote: ↑Mon Mar 23, 2020 1:06 pm That should work, but there will be oil thrown off the flywheel which may fill the breather up with oil. I am using the tach port on my TR25 race bike as seen here:

Breather on TR25.jpg

The O2 Sensor you got there seems pretty close to the head. Is there a specific reason for that?

Shawn_Mc

Nope, the B25 uses social distancing between the primary and engine oil.

The B25 primary breather are these tiny little holes in the fill plug.

Speaking of breathing, why doesn't anyone use the "timing plug" on the front left side for a breather? B50 or B25.

Shawn_Mc

Thanks Shawn. You are the second person to recommend the Electrex so i will likely go with that. Is it simple to install and set up? Also where did you purchase it from. I see you are in SoCal as I am (Redlands). I got it from Peter Quick at BSA Unit Singles. It really is easy to install. All you n...

Shawn_Mc

On my clutch spring nuts there is a hole to wire though to stop them from backing off Mine too, but the clutch slips if the nuts are back out far enough to take advantage of the hole with safety wire. I probably just buy new springs. A new set of clutch plates probably wouldn't hurt either. We'll s...

Shawn_Mc

Very nice I do like the provision to change the angle of the rear shocks and the centre stand >44 You like that stand? LOL....Took me twenty minutes and cost me $30 bucks. I was using one of my standard Moto stands and both wheels end up a foot off the ground and a bust my back picking that dinosau...

Shawn_Mc

The Wassell ignition is good, why not just fit a capacitor and keep the Wassell ignition. Electrex support seems hit and miss. https://granttiller.com/2020/02/13/electrex-world-unboxing-fitting-opinions/ Well, these guys struggled, that's a fact. But, I just put an Electrex on my B25 and it fired u...

Shawn_Mc

It'd have to foam the entire volume of oil. Returning the oil to the back would give it more time to defoam as it made it's way to the front down tube also. As it is, the oil that gets almost completely by-passed just sits there while the "foamy" scavenged oil just dumps back into the down tube. And...

Shawn_Mc

I just mounted an Electrex on my B25. Pretty sweet. Spinning the engine over by hand with no plug makes a pretty significant spark. It's basically a PVL style and you cant beat it for the price.
No charging system, but if your setting up an MX'r, this is the ticket, IMHO.

Shawn_Mc

Once I get it complete and running again, I think I'm going to tear it all apart, powder coat the frame after I add some tabs to carry the side plates. I'll pull the head and barrel and have them vapor blasted, pull the side covers and the tank and have them professionally polished. The rear fender ...

Shawn_Mc

6. Drill a brass or alloy plug to .020" and insert that to a NP fitting into the oil pressure switch hole in the case. Is .020" enough? That doesn't seem like much oil. Granted, I'm used to flooding the rocker / valve train with oil to cool the springs, and that simply isn't necessary here..but .02...

Shawn_Mc

Speaking of Big Bore B25's has anyone seen this guy? https://www.youtube.com/watch?v=7DT7NUZTr9Y He makes a 300 out of an FJ1200 piston and cylinder. The only issue being the wrist pin is smaller on the Beezer rod. Easy fix. Or even easier, a phone call to JE to get one made with a smaller pin and n...

Shawn_Mc

If you put a check valve in the return off the bottom that is technically under pressure from the scavenge side, why couldn't you plumb that into the REAR of the frame to return there to circulate all of the oil, which would increase oil cooling pretty dramatically. I understand why you cant just pl...

Shawn_Mc

As well as boring out the throat and moving the studs, a boss needs to be welded (and machined) to the drive side case to take the extra bearing . Yes, as kommando says, Mark and Anita at CCM-Britain (aka Performance Engineering Services or PES) are tooled up to do this. While the cases are jigged ...

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