Author Topic: Lightened 500/550 Crank & Superods (Read 15447 times)

Greggo · « **Reply #25 on:** September 02, 2012, 03:46:34 pm »

Quote from: bwaller on September 02, 2012, 03:28:59 pm

Yes Yoshimura made a racing magneto for both 500's & 750's. I checked my old catalogue and it sure looks like that is what you have all right. By the way the price for the magneto was $136.14, the mag cover was 126.83!

I'm referring to the charging side, the stator.

bwaller · « **Reply #26 on:** September 02, 2012, 04:05:06 pm »

Me too. You have the mag rotor, but is the stator included? It doesn't seem to be in the cover.

Greggo · « **Reply #27 on:** September 02, 2012, 04:43:29 pm »

Scottly pointed out above that it appears to be a permanent magnet rotor on the end of the crank. The seller has told me the stator is included. Am I confusing the nomenclature? I don't see any magneto parts here. I see the rotor that Scottly pointed out, and the stock looking timing end on the other side of the crank.

Bill/BentON Racing · « **Reply #28 on:** September 02, 2012, 05:37:09 pm »

Greggo,you did well!

Bill

scottly · « **Reply #29 on:** September 02, 2012, 06:11:58 pm »

It might conceivably be a crank mounted magneto, that utilized the stock points. The rotor would have to be mounted on the crank in a certain location to phase the magnets with the stator, I would guess. When you get the stator, that will give some clues whether it's a PM alternator or a magneto: if the stator has only 2 or 4 poles, I would guess it's a magneto?

Greggo · « **Reply #30 on:** September 02, 2012, 07:20:11 pm »

Scottly, you're kind of blowing my mind here. I guess I'll have to stop speculating. If there are other pieces I have to buy from him later on, I'm sure it wouldn't be a problem.

scottly · « **Reply #31 on:** September 02, 2012, 07:28:11 pm »

In the 4th pic, on your first post, Greggo, there is some sort of cover above the oil pan, with 4 mounting holes. Does the stator cover you posted in a later pic bolt onto that? (Sorry, not that familiar with 500/550 parts)

bwaller · « **Reply #32 on:** September 03, 2012, 03:48:24 am »

Sorry if I complicated anything. In the Yoshimura catalogue they call it a racing magneto, the stator seems to be four pole? They also advertise a fixed advance point cam with the above.

Greggo · « **Reply #33 on:** September 03, 2012, 08:38:08 am »

Quote from: bwaller on September 03, 2012, 03:48:24 am

Sorry if I complicated anything. In the Yoshimura catalogue they call it a racing magneto, the stator seems to be four pole? They also advertise a fixed advance point cam with the above.

No, please, any and all help is appreciated! I posted this to better understand what I'm getting. I'm talking with the seller Tuesday, and I'll be sure to ask if he has any magneto parts as well, even if they have to be sent separately, as it's all packaged up already.

I've seen an online copy of that brochure somewhere, but can't find it now..

scottly · « **Reply #34 on:** September 03, 2012, 06:57:08 pm »

The rotor, the stator, the stator cover (and the other cover I mentioned?), and the fixed advance point cam bwaller mentioned are the magneto parts.
Don't confuse this mag with the Fairbanks-Morse mags used with the ARD mag drives; it's the same machine, but in a much simpler package.

The way a magneto works is to generate a pulse of current when the permanent magnet moves across the poles of the stator. When the current is at it's greatest, the points open, and you get a spark. This is why the rotor has to be phased properly. It's the same type of system used with dirt-bikes, lawn-mowers, chainsaws, etc. Most of this systems don't have any provision for headlights or battery charging, but some do. Since the Yosh was advertised as a racing unit, it probably doesn't.

If you look at any stock SOHC stator, you will see the inside is cut into a bunch of segments, with a bunch of coils. Each of the segments is a pole.

Greggo · « **Reply #35 on:** September 03, 2012, 08:00:58 pm »

Quote from: scottly on September 03, 2012, 06:57:08 pm

The rotor, the stator, the stator cover (and the other cover I mentioned?), and the fixed advance point cam bwaller mentioned are the magneto parts.
Don't confuse this mag with the Fairbanks-Morse mags used with the ARD mag drives; it's the same machine, but in a much simpler package.

The way a magneto works is to generate a pulse of current when the permanent magnet moves across the poles of the stator. When the current is at it's greatest, the points open, and you get a spark. This is why the rotor has to be phased properly. It's the same type of system used with dirt-bikes, lawn-mowers, chainsaws, etc. Most of this systems don't have any provision for headlights or battery charging, but some do. Since the Yosh was advertised as a racing unit, it probably doesn't.

If you look at any stock SOHC stator, you will see the inside is cut into a bunch of segments, with a bunch of coils. Each of the segments is a pole.

I think I'm following. I'm trying to learn a little more about race bikes, so forgive me if I sound slow. Because there's no battery to charge, the left side of the crank (used for charging on a stock bike) is used for triggering a magneto, leaving the right side of the crank (used for ignition on a stock bike) blank.

The piece on the end of the crank in the top right of this pic then would possibly be that rotor, correct?

scottly · « **Reply #36 on:** September 03, 2012, 08:19:11 pm »

Yes, that's the rotor. The rotor and stator on the left end of the crank generate the current pulses that charge the ignition coils, and the points on the right side still act as the triggers.

Greggo · « **Reply #37 on:** September 03, 2012, 08:24:01 pm »

Quote from: scottly on September 03, 2012, 08:19:11 pm

Yes, that's the rotor. The rotor and stator on the left end of the crank generate the current pulses that charge the ignition coils, and the points on the right side still act as the triggers.

Interesting. Would the stock advance be used as well?

scottly · « **Reply #38 on:** September 03, 2012, 08:28:47 pm »

Quote from: bwaller on September 03, 2012, 03:48:24 am

They also advertise a fixed advance point cam with the above.

Greggo · « **Reply #39 on:** September 13, 2012, 05:35:16 pm »

You guys happen to know if any of the 500/550 yosh cams had a '2' stamped on the end?

bwaller · « **Reply #40 on:** September 13, 2012, 05:51:59 pm »

You might ask Colin about the Yosh cams. Seems to me he has a stockpile.

Greggo · « **Reply #41 on:** September 13, 2012, 06:38:39 pm »

Thanks! Sent him a PM.

Greggo · « **Reply #42 on:** September 13, 2012, 07:33:47 pm »

Got everything in the mail, and I'll be damned, the journals are toast

BUT, that's where the bad news stops.

Because I think that's the magneto rotor!

Oh, and I'm happy to report that the hi-po cam was not for a 750, but a 500/550 indeed! It's stamped '2' on one end, and it looks to be the same font as the 'B' on my Yoshi cam. It is unused..absolutely perfect lobes.

Also, the rods spin freely, like butter. I'll have to take them off, so where should I start to look for bolts?

Greggo · « **Reply #43 on:** September 13, 2012, 08:25:25 pm »

I found this pic of the part I've got on another thread.

Is the fixed advance breaker cam at the top right?

I only see three prices listed, but I see four parts there. The cover, the advance cam I'm assuming, and the magneto consists of both parts on the bottom? So, I've only got half the puzzle, yes?

Thanks for any help guys. If the seller has any of these parts, it's much better if I can describe to him exactly the parts I need.

Greggo · « **Reply #44 on:** September 13, 2012, 08:33:06 pm »

Sweet, on that same thread I found the same cover I saw in one of the pictures, so I'll be sure to get that.

My magneto looks more like the 750 part in the first pic than the 500 part in this pic.

Greggo · « **Reply #45 on:** September 14, 2012, 08:14:40 am »

Possible the cam is a Yoshi Stage 2? They made Stage 2's for 500/550's, yes?

Greggo · « **Reply #46 on:** September 14, 2012, 02:32:32 pm »

Quote from: Greggo on September 14, 2012, 08:14:40 am

Possible the cam is a Yoshi Stage 2? They made Stage 2's for 500/550's, yes?

~~Okay, I'm fairly certain the cam is not Yosh. I set it next to my 'B' cam, and the lobes are taller by about 1mm. The unknown '2' cam doesn't have the same markings on the shaft as the 'B' cam.~~ It does have a couple other marks on the shaft opposite the tach drive that read:
'2620
4-3'

The gold tint is from old grease. The lobes look billet or hard chrome.

Here is is next to the 'B' cam

kayaker43 · « **Reply #47 on:** September 14, 2012, 04:33:28 pm »

Greggo,.. I have the 550 super rods too. Let me know if you find bolts. If that's a yosh crank, save it for a pattern to duplicate.

Just to tease you I have some not for sale close ratio transmissions

Another tease. There's a pair of Yosh magnesium fork legs on ebay now.

Might be cheaper to collect space shuttle parts?

Greggo · « **Reply #48 on:** September 14, 2012, 04:37:50 pm »

Quote from: kayaker43 on September 14, 2012, 04:33:28 pm

Greggo,.. I have the 550 super rods too. Let me know if you find bolts. If that's a yosh crank, save it for a pattern to duplicate.

Just to tease you I have some not for sale close ratio transmissions

Another tease. There's a pair of Yosh magnesium fork legs on ebay now.

Might be cheaper to collect space shuttle parts?

I saw those legs this morning...kind of a lot for just lowers with cracked clamps.

Any idea about the '2' on this cam? Ever seen that before? I'm going to contact Dynoman about bolts.

Greggo · « **Reply #49 on:** September 14, 2012, 05:50:30 pm »

Cleaned off some very caked on oil.

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Author Topic: Lightened 500/550 Crank & Superods (Read 15447 times)