Topic: Is there a source for the 12mm dowel pins?

[roadkill savior]

My dealer says they are discontinued through Honda and can't get them. I heard that there are automotive ones available but they are a little shorter. Is there a source for a 20mm tube that I can cut my own, if nothing else?

Thanks, Matt

[HondaMan]

I've got a lathe, if nothing else... 

[Kevin D]

I got one from the local dealer, 94301-12200 (12x20).

I found it on the ST1300 partsfiche, adjacent to the head gasket, after I was told that the 94301-12220 (12x22) that my CB calls for was obsolete.

[rbmgf7]

what does this place not have? (besides NOS honda parts)

http://www.mcmaster.com/

[shoemanII]

i have a couple of 12 x 18mm dowels from my bike, are between the cylinder and base.  no charge of course. 
bobp

[754]

Mc Master Carr will have a lot of dowels, but the thin ones is not an industrial type part.

how are they getting needed, are they corroded or are you removing in a manner that harms them? sometimes you can run a tap in them and remove easily. I designed a puller that pulls HD ones easily with no damage, but they have a thicker wall, Hondas are pretty thin..

 Be careful if you make them, undersize may allow movement leading to leaks..

[mystic_1]

Particularly on older engines, I've found that the knock pins usually have at least some corrosion on them, and some I've seen were very nasty indeed.  As a result, they're difficult to remove without damaging them, mostly due to their thinness.  Even un-corroded ones can be a little hard to remove as they're a tight fit.  Many people's first instinct is to grab them with pliers or needlenose pliers, and they're too thin and fragile to stand up to that if any real force is applied.

How does your puller work, 754? 

mystic_1

[754]

The HD ones are about 100 thou wall thickness, I built a shaft with a lip, the id  of dowel matched the minor size of the shaft, the lip a bit bigger to catch the bottom of dowel, then tap the shaft and slit it....allows it to be pushed together at the slit and slide thru the dowel.. then install screw  (inside puller shaft)and a spacer up above dowel, bigger id. The put a washer across the top of the spacer and wind out with a nut.

Looks like a bushing or bearing puller Snap-On sells.

 Sooo, if we figure out how small the oil passage in a Honda dowel can be and the ledge the dowel stops on is thin.. then we could probably make a slightly thicker wall dowel for the Hondas, that with the puller, would last 4ever..

[HondaMan]

Nice tool, 754! Good thinking...

The oil passage can be the minor diameter in the block leading up to it. I think Honda just made these dowels thin to save material costs, nothing more. They can be considerably thicker. The ends must be slightly tapered for insertion, of course, but I have hand-tapered some with 320 grit emery paper in a few minutes: that's enough taper.

[754]

Its just part of how I think, I work on a lot of different stuff, and often you get crossover, something off one works on another, or you take part of an idea and tweak it or combine to get a result.

 I read stuff like streetroddder to get ideas for billet goodies for bikes, and new fasteners, stuff like that..and for the EXCELLENT metaworking series they ran..

 I think the Honda dowels can be a bit thicker just so long as they are not smaller than the smallest portion of the oill passage..

[754]

Thje other dowels are 2mm thick, the prtion of the tool that grabs underneath is .75mm or .030 high.

This method will work, as long as the shoulder the doel sops against is thin, and there is enough meat left on the dowel for the lip to grab.
Thicker dowe;s will solve oit once and for all...

[markb]

I found it on the ST1300 partsfiche, adjacent to the head gasket, after I was told that the 94301-12220 (12x22) that my CB calls for was obsolete.

I think the reason it is obsolete is it was too long.  I messed mine up removing them and when I went to replace them I measured the holes in the mating parts and it was barely 20mm total (didn't measure the pins before I threw them).  I actually ended up using 18mm long.  I also measured the hole depths on the head to the cylinder and the pins that came out were almost exactly the same length as the depth of the holes plus the head gasket so I went with the next shortest there also.  I was concerned that if the gasket squished out too much that the pins would bottom out in the holes maybe contributing to a head gasket leak.  Anyone else seen this?
Mark

[mystic_1]

That's an excellent observation, markb, sounds right to me.

BTW, for anyone who doesn't already know this, the second half of the part number for honda knock pins is based on the size, so for example


94301-12220 = 12x22
94301-12180 = 12x18
94301-08140 = 8x14

cheers
mystic_1