Odd starter clutch failure

[mbrood]

Well, I tore into the starter clutch. It would "bang and grind" every once in a while and since it's a good time of year, I figured what the heck.

 

Once I got it off, I looked down at the pillow, laid there to 'catch" the flying rotor (thanks guys.. that's a marvelous money saving trick!) and I saw three dowels, two spings and two spring cups... TWO???

 

The bronze (or???) housing that the springs and dowels fit into had ONE spring cup still in it... slightly recessed... so IT was NOT doing it's job.

 

So I tried to tease it out by gently pushing it in (VERY slight movement)... after an hour I was able to get it flush with the edge. After another hour I was able to get it to wiggle out about 1/3rd. I finally got it out and saw that the sides looked ok... (IT'S on the left).

 

http://www.bergall.org/temp/venture/starter/starter%20clutch2.jpg

 

So I blew out the recessed hole it sat in with WD40 and tried slipping in one of the other spring and cups and it slid in and bounced up and down just fine. I started really looking at the three spring cups. ONE had the open end just pristine but TWO had edge damage and the one that had hung up actually had a nick (or future chip?) that was hanging out... the outer diameter of the three is .248 and the open end at the nick spot was .252! Must have been just enough to snag and disable a third of the clutch! (The "offending" cup is still on the right.)

 

http://www.bergall.org/temp/venture/starter/starter%20clutch3.jpg

 

The parts fiche shows an odd part in the bottom of that recess, no part number though.

 

SOMETHING is causing the edge to chip and this just is NOT a good thing. Either the spring cup has too much slop in the hole (sure doesn't feel like it or that .004 "nick" would still fit?)) or the cups are bottoming into something and chipping.

 

Nonetheless, it's enough that it caused the cup to seize.

 

The idle gear #2, that has the race attached that the dowels drive against, had a distinctive "dance mark" pattern where the dowels had driven in so that's an easy solution to repair...

 

http://www.bergall.org/temp/venture/starter/starter%20clutch1.jpg

 

I figure, once the bike starts, centrifugal force throws the dowels back against the springs and the cups are driven deep into the hole and maybe THAT is what leads to the chipping...? Any ideas?

 

The bike only has about 46,000 miles.

 

Here's a breakdown of needed parts from two web sites and my local Yamaha shop... and the shop wonders why I won't buy from them???

		Flatout	Zanotti	North County Yamaha
Bolt (3 needed)	91316-08014-00	.99	.80	2.48
Gear Idler #2	26H-15517-00-00	29.86	28.64	46.67
Whole Starter Clutch	11H-15580-00-00	74.54	73.68	109.24
Dowle Pin (3)	93615-12088-00	1.64	1.57	2.55
Spring Cap (3)	341-15583-05-00	4.76	4.57	7.44
Spring (3)	90501-04623-00	1.59	1.52	2.46
Left engine case gasket	3JP-15451-00-00	5.10	4.89	7.97
Rear case gasket	3JP-15461-00-00	1.80	1.73	2.97

[Squeeze]

Instead of buying all the Parts and come back to the Issue one Time in the Future, send the Flywheel to PCW Racing and be done with the Starter Clutch forever

 

http://www.pcwracing.net/featured.htm

[mbrood]

There sure isn't anything there to say WHAT is special or going to be so great... I still see three springs, spring cups and dowels... for $180.

 

http://bergall.org/temp/venture/starter/start2.jpg

 

Do you have relevant info?

 

I figured on replacing the ilde gear, cups, springs and dowels... $58.24

[Squeeze]

I have Information from three Guys who have had it done. Works great was all they said.

 

I did not get any Infomation or Explanation about what has to been done. All excited about getting the Bike back on the Road, they did not take a Picture or a closer Look on the Parts they received. They just putted it back together and ride the H..l out of their Maxxes.

 

I have my Opinion about has happened, but as long i haven't confirmed and tested that, i won't talk about it. Maybe you give PCW a Call and talk to one of these Guys ? Maybe they enlighten you, at least you can ask them, what will be much better with the same 3 Pins, Dowels and Rollers Setup?

 

What i've heard, these Guys are very nice to deal with. Polite, customer-friendly and John Ganey seems to be a Heck of Guy with all his Knowledge about these Motors.

 

Btw ... your figured 58 USD are only half Way, i know several Guys who tried to save the big Money and had to redo everything 3 to 6 Months after their first Attempt. The Idle Rear could be safed in almost half of the Jobs. You better do not mess around with this, pulling the Flywheel again is not Fun at all, and i wouldn't want do the Job more than once on my Motors.

[mbrood]

I talked to john about their clutch...

http://bergall.org/temp/venture/starter/start2.jpg

 

He said they take a STOCK clutch/rotor assembly and machine the rotor to accept heavier and longer bolts to hold the clutch on. He said the failures he designed to get around was the weak bolt mounting technique that Yamaha designed. His claim... no more bolts working loose.

 

He said this was done primarily for the VMax that turns at higher RPM and sees more "abuse".

 

Looking at the rotor, the bolts come in from the back into the inside edge and actually cut part way into the contour of the center shaft flange. I figure they machine around these bolt holes to create a larger flat area and probably use an insert for more and deeper thread, or they may just go with a longer bolt backed up with a locking nut. Either way would definitely improve the design.

[Squeeze]

Hey, thanks for investigating this and enlighten this Issue.

 

I can see that this Upgrade works. The stock Bolts are Allen Head M8x25 in Grade 10.9. If John Ganey uses M10 Bolts this would add some Stability on the Assembly. Either the Bolt Heads need to be turned down to fit in the Clutch Housing or he's milling the Housing to accept bigger Bolt Heads.

 

I will look in the Parts i have laying around if there is Chance of determining this specific.

 

Since this is no big Deal, it's good Investment. If you know someone with a metal Shop, they might get this done for you locally.

[Squeeze]

I'd taken a Look at the old Parts i have lying around.

 

There's no Way modifying the Clutch Housing to fit standard M10 Allen Head Bolt.

 

So PCW take M10 Bolts and turn them down to 13 mm Head Diameter and 8 mm Head Height, bores the M8 Threads in the Flywheel with 8.8 mm and tap them with M10.

[Dano]

Another mystery solved by Squeeze!!

[Cutty]

I think the mod is for Max's with more compression, hence the larger bolts. Check your starter clutch for pimples on the outer edge, this should be smooth. Getting 50K out of a stock unit seems within limits, not knowing if this is a motor used for short runs and a lot of starts. Check starter brushes and comutater ( mght need a little dressing up) . Lube shaft and replace flywheel.

[GeorgeS]

I replaced mine at about 55K. It started makeing noise around 40K.

 

My comment would be, if over 50K on a 1st Gen, and never been replaced, you most likely need to do the job. Its just a matter of time. You might as well get the parts ordered.

 

Consider it a good Winter job.