Topic: CBb750 K0 Spark Advancer Shaft Removal

[JP04/70CB750K0]

Can the spark advancer shaft be removed without tearing down the engine.  I want to replace with new shaft from the Exterior of the engine.  To remove, do you turn counterclockwise or clockwise?  Can it be removed using stud puller without snapping off inside the crank.  Mine has end treads damaged and cannot hold 6mm nut tight enough to prevent wobble.

[HondaMan]

This shaft unscrews from the crankshaft in the normal direction, CCW. BUT...when I have replaced broken ones in the past, the O-rings that came with the new shaft were not big enough on the OD to stop the oil from leaking out of the end of the crankshaft. This shaft is also a 'plug' into the oil pressure that runs thru the crankshaft journals, so it is hot and running at 60 PSI. Honda made a special O-ring for this shaft because of it, and the ones that I have received with the aftermarket shafts have NOT worked. They leaked oil, and lots of it!

Honda's part number for this fancy O-ring is:
91301-300-000
O-RING (6X2.3)
and the fancy shaft in the correct dimensions is:

30231-300-010
SHAFT, SPARK ADVANCER (NOT AVAILABLE)

While listed as not available, I've bought them from DSS in the recent past.

[JP04/70CB750K0]

Thanks for info. Follow up question.  Will collet type or gear grip type remover work?  Which is best to not over tourqe the shaft and how tight is the shaft going to be.  Both tools will grip close to o-ring but which is safest to avoid breakage?

I will verify o-ring dementions when it arrives.  Ordered from source in Japan that reproduces shaft.

[PeWe]

www.yamiya750.com has that shaft with o-ring.

[JP04/70CB750K0]

Thanks, received today.  Now my problem is how to unscrew advancer shaft without the crankshaft turning.  When i put leverage on the stud remover, the crank turns backward and I can't break the shaft loose.  Hope this doesn't mean I will have to remove the newly installed stator Cove to get to the other end of the crank to get counter leverage.

[PeWe]

5th gear in and something blocking rear wheel will help.

[JP04/70CB750K0]

Thanks all.  I put in 5th gear, used side stand to lock rear wheel, used heat, more Blaster, heat, collet style stud remover, pressure ( slight) on wrench handle while lightly taping wrench head with hammer, and bingo, suddenly move and came right out!  I did add duct tape to the shaft as the collet minimum was 6mm giving just enough resistance to hold.  Very scarey.  See how these can snap off.  I placed collet right up to the o-ring shoulder to reduce possible twisting and breaking shaft.

Now back to setting timing, hopefully without jitters.

[BenelliSEI]

Congrats. Always a “scary” job. I’ve used one from Yamiya, fit perfectly and did not leak.

[HondaMan]

Congrats. Always a “scary” job. I’ve used one from Yamiya, fit perfectly and did not leak.

Good to know! I haven't used Yamiya's version (yet).

[jebon]

Hi all.
I have a similar oil leak and am about to inspect this shaft and o-ring.
Can someone please tell me if there's supposed to be an o-ring on the outside as well?
I mean in the inner groove on the shaft behind the advancer. An o-ring would fit nicely in there but mine hasn't got one.
Thanks!

[MauiK3]

Maybe someone could put up a little video of removing one.

[jebon]

Maybe someone could put up a little video of removing one.

I can film when I try removing mine

[Don R]

 I removed one yesterday with the double nut trick, I had to squeeze the wrenches together while simultaneously turning them. It required a quick move that seemed to have broken the stud but it was just the sound of the threads releasing.
 I'd be careful with heat, you don't want to ruin the seal. Mine was out of the engine, I removed it for storage reasons.

[jebon]

Can anyone confirm if there should be an outside o-ring in the groove behind the advancer?

[newday777]

Can anyone confirm if there should be an outside o-ring in the groove behind the advancer?

As you can see adding a different question on an old thread usually gets people answering the original question rather than seeing your question. Better to start new by hitting the new topic button.

[HondaMan]

Can anyone confirm if there should be an outside o-ring in the groove behind the advancer?

No. There's only an O-ring on the inside groove.

[jebon]

Thank you 
I got mine out.
Sprayed the threads with brake cleaner and put an "alu washer" between the counter nuts.
The o-ring in place was indeed worn out.

I was wondering if a little Hondabond on the new o-ring would be a good thing or no?

[willbird]

Thank you 
I got mine out.
Sprayed the threads with brake cleaner and put an "alu washer" between the counter nuts.
The o-ring in place was indeed worn out.

I was wondering if a little Hondabond on the new o-ring would be a good thing or no?

We use a lot of O rings at work with AW68 and AW100 hydraulic oil at 2500psi. Once they have been in place and used for a year oir so they take a set and you can see what they actually look like under pressure. A normal round cross section O ring ends up looking like a square cross section O ring kinda under that pressure. IMHO you want the ring to move where it belongs and deform the way it was designed in order to seal, adding something like you suggested could prevent that as designed process from happening. Red Rubber Grease is IMHO the right stuff to use :-).

Bill

[jebon]

Thank you 
I got mine out.
Sprayed the threads with brake cleaner and put an "alu washer" between the counter nuts.
The o-ring in place was indeed worn out.

I was wondering if a little Hondabond on the new o-ring would be a good thing or no?

We use a lot of O rings at work with AW68 and AW100 hydraulic oil at 2500psi. Once they have been in place and used for a year oir so they take a set and you can see what they actually look like under pressure. A normal round cross section O ring ends up looking like a square cross section O ring kinda under that pressure. IMHO you want the ring to move where it belongs and deform the way it was designed in order to seal, adding something like you suggested could prevent that as designed process from happening. Red Rubber Grease is IMHO the right stuff to use :-).

Bill

Thanks