86 CB700S starter chain

[私はホンダに乗る]

Hi All! I was I_Ride_Honda on the other site a couple years ago. Glad to see the community is still going strong. I haven't had time to ride much as I'm fishing and hunting pretty much full time up here in AK.
As for my bikes, none are running right now. The low mileage 86 NH was my go to but went to do the monthly start and the starter chain broke. What would be the most prudent way to go about getting this apart and back together before my short riding season here? I'm hoping to repair the chain and not need to do any machine work except a light hone on the jugs.

[mollusc]

The whole process is well described in the Honda Service Manual, which you should get a copy of immediately.
Once you get down to the starter chain, you can replace it with the chain from the 1996-2003 CB 750.  If the starter chain tensioner rod is damaged, it can safely be removed.
It's much easier to remove the engine assembly from the frame if you pull the head off first.

[Bob H]

low mileage 86 NH ...the starter chain broke.

I wish Honda would have taken responsibility for that mfg defect. Stuff like that should not happen to a low mile vehicle, but it is an all to frequent problem on the 84-86 NH 750.
I think if it was a Honda car, and soccer mom's were getting hit with quotes to split the case to access some failed part within the first 100k miles there would have been an uproar.

[mollusc]

Weren't many 750s made in 84-86.  None sold in the US.
But it's also known to have happened on the 650s of that era.

[Bob H]

Weren't many 750s made in 84-86.

Whoops - my typo. I meant 700s with the starter chain issue.

[私はホンダに乗る]

Am I understanding correctly that the alternator chain doubles as the starter chain as well? Is this the correct part? https://www.cmsnl.com/honda-cb750-nighthawk-1999-x-usa_model7236/chain-acgenerat_28161mj0950/
Are there quality gasket sets available? If so, I can't find them. I am not above making gaskets if necessary, I have a laser cutter that should work perfectly in a pinch on the paper gaskets but I really need a gasket set to not have leaks.

[mollusc]

Yes, the starter chain also drives the alternator.  If you look in the service manual you will see that clearly.
I think the part you link to is the correct one, but €97.00 is a huge price.  You want Honda part number 28161-MJ0-950 which is listed for $52 at https://www.hondaparts-direct.com/oempartfinder#/Honda_Powersports/CB750A_(00)_NIGHTHAWK_750%2c_JPN%2c_VIN%23_JH2RC380-YM800001_TO_JH2RC380-YM899999/STARTING_CLUTCH/9e4be468-b97d-402d-82ba-ed911ae60077/ea701bfe-3873-4701-adba-00dff6e793e9/y

Gasket sets are also available from the same seller, although the diagrams on the website don't match the descriptions for those.  I would call them to ask.
Or check on eBay.  I think the last Vesrah set I bought was from there.

[私はホンダに乗る]

Thanks mollusc, I got the chain delivered to the door for $73.95. Shipping to Alaska is beyond brutal at times... Having an interesting hunt for VG-1073-M, Vesrah's gasket set. It's sold out everywhere so far but I did call one place and he said that his 'puter said he'd have some available on the 11th of this month. We shall see. I went to Vesrah's website and it's truly pathetic so no ordering from there. I'll find one. Gonna start disassembly today. I now have an factory Honda service manual.

[Pete in PA]

Should think long and hard about every part you encounter going in.  Valve job, piston rings, hone cylinders, starter clutch, etc.

Sucks this is a weak part and requires a complete tear down.

[mollusc]

Starter clutch issues are very rare.  I wouldn't touch that.
I replaced the rings and did a light hone when my chain snapped.  Also checked the main and rod bearings using Plastigauge.  Everything was in spec.  I always lap the valves whenever I have a head off an engine.
One thing to consider is modifying the case at the left end, in case you develop a crankshaft seal leak.  See my thread on the issue at https://nighthawkforums.com/index.php?topic=18
This mod can be done with the engine in the frame, so perhaps it's not so important during the starter chain process.

[私はホンダに乗る]

I have three NH S's. The bike I'm talking about now is an 86. I do have a spare engine and it's an 84 that I'll definitely mod using the procedure in the link, thanks for that. The other bike, an 86 as well, is in boxes here in AK but the frame is in FL atm. Retrieving it this coming summer...

[私はホンダに乗る]

I emailed Vesrah and they actually got back to me.
 
"Hello
Thank you for e-mail
Sorry
Production is currently halted for VG-1073-M

Thanks
Sato"
So what now, I'm coming up empty for an gasket set?

[mollusc]

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p4432023.m570.l1313&_nkw=cb700+gasket+set&_sacat=0

Or I provided you with a different link earlier.

[私はホンダに乗る]

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p4432023.m570.l1313&_nkw=cb700+gasket+set&_sacat=0

Or I provided you with a different link earlier.

Thank you very much.

[私はホンダに乗る]

A couple questions....ball hone for the cylinder bores or the spring loaded 3 stone style?

Is anyone familiar with the timing mod done on these engines? Advancing it one tooth or something? Why is it done and is it worth it?