Bendix Engages, Spins Engine 1-2 Revolutions, then Disengages and just Spins Starter ?

[E350]

Yesterday I put a new Interstate AGM battery (FAYTX20L)* in the 1996 701 Wave Venture and this is happening:

Bendix Engages, Spins Engine 1-2 Revolutions, then Disengages and just Spins Starter ?

If I were to throw parts at it, I would start with a new starter solenoid.

But what do you guys and gals recommend?

Any troubleshooting decision tree I should follow?

Any "very likely" it is this part, part I should try?

The ski appears to have been flooded before, there was rust and kinda thin film of mud in the E-box which I totally cleaned up and reinstalled.

*

https://www.costco.com/interstate-batteries-powersport-agm-battery-faytx20l.product.100655323.html

 

[bored&stroked]

If the starter is still spinning I'd imagine its not a solenoid problem. I'd guess bendix.

 

[E350]

Thanks. What can fail on Bendix? Bendix is just gear and spring correct? Take starter out clean up and grease?

 

[long beach local]

The bendix has moving parts that wear out , just find a minty used oem and replace it or you can try to rebuild it. New oem is the way to go but expensive

 

[Quinc]

bendix has little ears that hold the weights in place that can/will break off and cause issues. There is a thread on here somewhere with how to rebuild it.

 

[Sanoman]

What can fail on Bendix? Bendix is just gear and spring correct?

But a bendix is so much more than just a few parts

 

[Storbeck]

Part number 17 is what breaks, you can see the little ears between the weights and check if one is broken. It's a pain to get the clip number 19 off without stabbing yourself. So be careful.

 

[E350]

@Sanoman thank you for the exploded diagram. My Yamaha OEM Service Manual calls the Bendix the "Idle gear Assembly" with no exploded diagram showing the internal components.

Guys, you are not kidding a new bendix alone is $300 - $400. JetManiac sells a complete new oem starter for $429.

Can I remove the bendix from the front by just removing the flywheel cover and pulling the flywheel? If so, I have a "ok" bendix from a Yamaha 650 I could put in and try.
to verify it is the problem.

Also when I take out the current bendix can I shake it and listen to parts moving to know it is broken? Of is there any other way besides disassembly?

 

[TheBuzzard]

The small gear doesn't have enough resistance on it when you turn it in the direction it free wheels. The spring washers aren't working properly. That whole piece needs to be replaced. Thats why it cranks over forr a second and then doesnt.
A 2 second look at it tells if #17 is broke. Also the drum can detach from the big gear and spin separate from that gear

 

[E350]

@TheBuzzard Thanks! I have a Kawasaki 650 on the bench that I replaced the crank seals on a year ago waiting to have the accessories put back on.

The bendix from that engine is just sitting in a box. Can I put it in the 62t and see if that solves my problem?

I took the flywheel cover off the 62t in the Wave Venture and the bendix feels loose enough that I could almost wiggle it out without taking the flywheel off.

But my hunch is that I have to take the flywheel off -- correct?

 

[long beach local]

Yes you have to pull the flywheel

 

[bkspeedwerks]

@TheBuzzard Thanks! I have a Kawasaki 650 on the bench that I replaced the crank seals on a year ago waiting to have the accessories put back on.

The bendix from that engine is just sitting in a box. Can I put it in the 62t and see if that solves my problem?

I took the flywheel cover off the 62t in the Wave Venture and the bendix feels loose enough that I could almost wiggle it out without taking the flywheel off.

But my hunch is that I have to take the flywheel off -- correct?

yes you can use the kawi bendix. and yes you must pull the flywheel

 

[yamanube]

Have you inspected the teeth on your flywheel?

 

[WFO Speedracer]

What Yamanube said , most people don't realize that the bendix engages on one of two spots every time, eventually these teeth get worn down and the bendix will not stay engaged to the flywheel. Back in the day when the first Seadoo motors came out they ate starter clutches and ring gears, they did not have the engagement set right on them, after they fixed the engagement depth issue we really never had that issue again, but on thos flywheels you could clearly see two distinct spots of engagement 180 degrees apart from each other.

 

[mikidymac]

If the bendix feels really loose as you say, make sure you check the bushing in the case and cover for wear.

 

[E350]

Ok guys and gals playing along at home:

Flywheel Puller with Stops (courtesy of the buddy I lent the tool to):


Also notice the bad bendix from the Wave Venture above. Can you see the problem?
(I can see it now thanks to @Quinc @bored&stroked @Sanoman @mikidymac and @long beach local)

1. Nonfunctioning Yamaha 63N bendix from '96 Wave Venture in photo on top - extend it by twisting it out and look at what must be the centrifical weights: three weights, two almost touching, big gap between two weights, different size gap for other two - no uniformity in size of gaps.

2. Functioning Kawasaki 650 bendix from '88 X2 in photo on bottom - extend it by twisting it out and look at what must be the centrifical weights: three weights, uniformity in size of all three gaps.



Part # 17 is likely the part that is broken which is causing the lack of uniformity in the gap size between the centrifical weights on the nonfunctioning Yamaha bendix.

On the bendix you can use a small screwdriver and push the centrifical weights around making the gap larger or smaller by pushing them together. Not so on a functioning bendix where the weights are secured by the ears on the weight plate. So, use a little screwdriver to push the centrifical weights to see if they are secured by the ears or slide because the ears are broken off and the weights are unsecured.

I put the Kawasaki bendix in the Yamaha 701 engine and it functions flawlessly turning over the engine briskly and uniformly.

(However, the ski will not start but backfires. So I am in the process of pulling the flywheel again to check for properly lined up Woodruff key.)

I did spray the inside of the stator with QRC Contact Cleaner to clean the inside of the flywheel area but I don't think that would explain the failure to start/backfiring.

I also wirewheel brushed the flywheel (and removed all the metal debris from the magnets) before I reinstalled it. Even wire wheeled the flywheel between the gear teeth.



(Note: You can see some of the wire wheel wires stuck to the magnets in the photo above. It took a number of clean terry clothe towels to remove all the wires, because the magnets attract and hold them.)

Working with the flywheel cover, etc. with the engine in the Wave Venture is not as easy as in a Super Jet because in the Super Jet you can easily remove the fuel tank to have better access to the flywheel cover, etc..

 

[yamanube]

The backfiring may have been what killed the original bendix.

 

[E350]

Never back fired prior to my incorrect installation of flywheel. But that is interesting, how would back firing break the ears off the weight plate? Not doubting, just curious.

 

[WFO Speedracer]

There is a metal piece with tabs that goes in there top keep the weights separated this is what gets damaged on Seadoo 951'S and the pieces end up stuck in the stator coils

 

[yamanube]

Never back fired prior to my incorrect installation of flywheel. But that is interesting, how would back firing break the ears off the weight plate? Not doubting, just curious.

If by chance it backfires while cranking, or even just kicks back on it, it would shock the bendix assembly. That plate being fragile already may not live long under those conditions.
I also feel like, as these things wear, the springs weaken allowing the bendix gear to move around more than usual potentially causing the gear to contact the flywheel when running (on impacts while riding). Hold a bendix by the large drive gear and shake it nose down and you can see the nose assembly will pull out as you shake it around.