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Part number for Final Drive fill plug

Posted: Thu Mar 26, 2020 10:09 am
by WingNoob
Hey all,

Since I'm stuck at home I decided to do some spring maintenance on my new-to-me '97 SE. The DIY's on this site have been great, much easier to follow than the Clymer manual in most cases.

Anyway, I tried to change the final drive oil last night but the fill plug is completely seized in place and I rounded over the bolt head. I'm not worried about getting it out (a chisel and hammer should work fine) but I need to double-check the part number of the fill plug before I order a new one.

The part's fiche doesn't show the outside of the final drive housing but it looks like I should be ordering part #1 on the image (CAP, TAPPET ADJUSTING HOLE 12361-300-000) as well as part #32 (o-ring). Part #21 looks like it should be the drain hole plug, I might as well order a replacement for that one as well, just in case)

FYI, here is the link to the full fiche: ... riven-gear

Thanks for your input,

Re: Part number for Final Drive fill plug

Posted: Thu Mar 26, 2020 10:35 am
by Snowmoer
You are correct. #1 is the fill plug, #21 is the drain plug.

Re: Part number for Final Drive fill plug

Posted: Thu Mar 26, 2020 2:18 pm
by CrystalPistol
On my 1200 that I owned for 24 years, first cap was leaking when I first looked, very small leak, was a crack around it between edge and hex head, it wasn't tight no more. :D

I bought a new one with O-ring, put it on but was really careful with torque (probably pretty close to 9 or 10 ft lbs) as I didn't want to crack it too, then I drilled a hole across the hex where it was "more solider like", ran a 8 or 10" piece of 12 ga copper stripped out from unused or old romex, looped it through the new hole and around the vent tower, never worried about it backing off or falling out. Never leaked either, but always did refills after draining on center stand, letting level adjust it'self to threads in the fill hole before putting cap on.

Back in early 2000s was on a trip in mountains of eastern Tennessee and western North Carolina, stopped at a gas station, saw oil on my tan leather right boot, the oil dip stick of the 1200 was gone. I plugged the hole with a wrag to get home. used a coat hanger wire to make sure it had enough oil, come home … and bought a chrome aftermarket one, but it was made cheaply that I was afraid the stem could break off easily in the motor … so I got a metric bolt of same thread, drilled it, welded a tee on top for finger use, put a nut in place with a spot weld to serve as a sealing surface, beveled the bolt end threads like they should be, inserted a headless 19 penny nail in end hole I had drilled, added a spot of weld to hold that, then compared the nail reading to oil level using a borrowed OEM dip stick, marked my nail for the range like OEM, cut excess off, drilled hole in finger hold flat, used a wire on it too.

Did same safety wire deal on engine drain bolt or plug, but looped it around the nearby lower engine mount of frame.
Same on the 1500 trike, but I forget what I tied it off to, maybe a hole in a fin.

You just don't feel like it has to be so tight when it's wired too.

Re: Part number for Final Drive fill plug

Posted: Thu Mar 26, 2020 9:13 pm
by WingAdmin
Those fill plugs are readily available, Honda (still) uses them on many different models of motorcycles.

Re: Part number for Final Drive fill plug

Posted: Thu Mar 26, 2020 9:28 pm
by Rambozo
I would not be surprised if that is the longest continuous production part Honda has ever made. I have found at least one lurking on every Honda bike I have ever owned.

Re: Part number for Final Drive fill plug

Posted: Fri Mar 27, 2020 6:50 pm
by WingNoob
Thanks all.

Ordered both plugs and o-ring/washer from the local dealer yesterday. In stock in the Toronto warehouse, should be here in 3-5 days. I'm betting more like 7-10 given current conditions. No biggie. I'm fine riding a while on the oil that's in there. Also went ahead and ordered fork seals and bushes since one of the seals is weeping slightly. Better to do it now than wait for complete failure.

And CrystalPistol, good idea safety wiring the plug(s). I do that on some of the more critical components of my KLR, which has a tendency to shed parts at the most inopportune of times... One additional benefit is that if you slightly oversize the hole in the bolt head, you can fit a small steel nail through the hole which can be used to get some extra leverage if the bolt head rounds off.

Re: Part number for Final Drive fill plug

Posted: Fri Mar 27, 2020 7:47 pm
by 1goldwingnut
It's the tappet adjusting plug on a 73 cb350 too. Fits older ones also. Longest running part for sure.

Re: Part number for Final Drive fill plug

Posted: Sat Mar 28, 2020 12:52 pm
by bellboy40
I think those are the same plugs that were for the tappet covers on the 76 CB750 I used to have. I also noticed Cyclemax has them in stock for $7.50.