Announcement

**clarkcortez** · 10-21-2004, 11:00 AM

I am very familiar with this dowel pin and 0-ring because I am rebuilding at this time. It is located between the case halves and to the rear of the center main bearing journel. This is the only dowel pin I know of that has an o-ring. According to the manual it is essential that these parts be installed properly or you will toast your engine. Guaranteed! I'd hate to see you trash your engine after all your hard work.

**randy** · 10-21-2004, 11:13 AM

Scott,

According to the fiche on Yamaha.com, it looks like that dowel and o-ring go right next to #3 main bearing cap. Looks like an oil galley, hence the grommet. Hate to say it but if that's the one, you're headed for an internal oil leak, low oil pressure and eventually main bearing failure.

HTH

Randy

**dweomer21** · 10-21-2004, 11:24 AM

thanks for the (unfortunate) advice. Well, I am going to ride it and keep an eye on the oil pressure. I'd rather waste the $800 I bought the bike for, and the $400 I spent on parts, and the 100 hours I've put into it, than take the thing back apart right now... (that may sound crazy, but, that's the truth). Also, I'm wondering if anyone has one of the dowel pins mentioned in the above posts lying around they could measure for me? The only thing that strikes me is that it seems to me the dowel I have left over is a bit too small to be the crankcase one...that, and I am 99% sure I put that one back in.
If someone could give me diameter/length, I may be able to rule it out.
Thanks guys,
Scott

**clarkcortez** · 10-21-2004, 11:54 AM

Can't measure dowel pin in question as it is already installed. Small sidecover pins measure 10 mm o.d. Large locating dowels measure 14 mm o.d. Was the o-ring still on the dowel?

Yamaha description of parts for a 79 XS standard:

37 91830-21014-00 PIN, DOWEL (8.5-10-14) 1 [oil galley dowel]
38 93210-09350-00 O-RING (1.9-8.8)

2 91830-22016-00 PIN, DO [Locating pin]

**dweomer21** · 10-21-2004, 12:45 PM

no, the o-ring and the dowel are both in a baggie of misc small parts I had when I disassembled, but the o-ring wasn't mounted on the dowel. I still think (and hope) that this could be a coincidence - that the dowel is from some side cover, and the o-ring from some other place (both of which would still be important, but not as important as the oil galley deal).
Anyway, the local yam dealer here has a couple of oil galley dowels in stock, and I'm going down there during lunch to get some measurements. It's actually a superceded part, but should have the same diameter and nearly same length, I'd think.
scott

**John** · 10-21-2004, 01:13 PM

Was the leftover dowel hollow, and about 3/8-1/2 inch in diameter? If so, then it is the oil galley tube. I would recommend coing back in to install it. Oil pressure problems would eventually result if you don't.
Why is there never enought time to do the job the first time, but always time to do it over?

**dweomer21** · 10-21-2004, 02:12 PM

Yes, hollow, and about those dimensions. *sigh* I don't even know what to do now. S**t. I simply cannot even fathom taking the engine back apart again. That, and I am half expecting to find the dowel already in there when I'm done...
So, how EXACTLY does that oil galley fall in with the oil system? I am trying to envision what will be disrupted without the dowel in there. Does oil come out of the pump, and go through the galley, then into the the crank journal bearings? Or....?
Is there any creative way anyone can think of to tell if the dowel is already in place (probably not, without some futuristic star trek tri-corder)? Or, if I leave it out for now, is there a way to monitor the oil pressure carefully enough that I will be guaranteed to know when/if there is an internal leak due to it not being there?
thx
scott

**randy** · 10-21-2004, 02:27 PM

Scott,

We all feel your pain, but trying a shortcut now will only lead to severe damage down the road. When is anyone's guess, but when it does happen it will be catastophic and the parts involved are very expensive.

Cheaper and safer to do it now. Besides, you've already done it once, the second time should be easy!

Keep in mind that no matter where the oil pressure loss is, it will affect the main bearings. More when you start to push power out of the motor. That o-ring is south of the mains, but without it the oiling system in general will be down on pressure.

Here's how you can find out if you actually left the o-ring/dowel out:

Get a mechanical oil pressure guage and connect it with a tee connector at the oil pressure sender (the switch screwed into the block right under the carbs).

Start the motor and read the guage. If I remember correctly, 15lbs/sq in is right.

Anybody know otherwise??

If the pressure is right, you're OK. If the pressure is low, get out the wrenches. BTW, you will only have to remove the lower case half & some shifter parts, no need to disturb the top end.

HTH

Randy

**dweomer21** · 10-21-2004, 03:59 PM

Randy,
Thanks for the advice - it seems there is hope :-)
A few quick questions.
First, you mean take the oil pressure switch out, and screw in a coupling that I can put the presure guage hose over? The switch is just a switch right? I mean, I'd have to remove it to be able to sense the pressure right? And why a "T" fitting?
Also, you say I will only have to remove the bottom crankcase half, which I can understand, but how do I do just that? flip the whole engine over, then remove the bottom half crankcase that way?
Thanks for the info! This makes me slightly more positive about the situation

Also, anyone confirm/deny the oil pressure amount?
scott

**ratbyk** · 10-21-2004, 04:17 PM

Oil Pressure

The oil pressure on my 78e is 65-70 cold on start up at 3000.
Once warmed up it runs 40-45 at 3000. 15 hot at idle. I have seen a few other posting on XS oil pressure and all the good strong running motors have pressure in this range.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

**John** · 10-21-2004, 04:20 PM

You do have a manual, don't you? Just remove all of the crankcase bolts, i sequence, 34 of them, if I remember correctly, and after removing the clutch cover and shifter cover, look for anything that is attached to both case halves and remove it. The middle drive will also have to come off again.. Turn the engine upside down and seperate the two halves. Look for the oil tube. Betcha' won't find it in there. Be sure to use plenty of yamabond or a product called three bond when reassembling. Be generous with it. Make sure to use it where the main bearing saddles meet. Don't worry about it squirting out. It will just roll right off the cases with your finger after it has time to set up. Did you replace both crankshaft end seals? Now is the time to do it. Bikebandit has them for about $7 each. Did you replace the O ring on the oil galley plug on the lower right side of the case, the oe with the pointed tab, that is held i place by tghe alternator cover? That ca leak too. Do not run the engine with the alt cover off. It will blow that plug out and create one helluva mess. The top end(cylinders and head) will remain undisturbed during all this.
Good Luck

**randy** · 10-21-2004, 05:09 PM

Ken,

Thanks for the correction.

Boy, I was WAY off.

Randy

**dweomer21** · 10-21-2004, 06:52 PM

Sweet, thanks john, I'll do that. So, just to reiterate what you said, I DON'T have to take the head/cycinder off right? I don't even have to remove the head cover. Take off the oil pan, disconnect everything needed to take the entire engine out, then flip entire engine assembly upside down, and remove lower crankcase? I hadn't even thought about it before, but it sounds like you're saying that taking lower crankcase half off to put the dowel in will be relatively painless, huh? If this is the case, I am not dreading this procedure as much as I was before!
Thanks again!
Oh, one more thing... in case I DO want to check oil pressure first (as per Randy's post above), is a mechanical oil pressure guage a pretty easy thing to get? Just hook it up in place of the oil pressure switch and monitor it closely under various temperatures/rpms, yes? Mechanical guage, I assume, means a guage that will prevent oil from coming out of the oil pressure switch's hole, and simply give me the resulting pressure?

Scott

**John** · 10-21-2004, 07:19 PM

You can install the gauge in place of the sender, or on the left side of the engine, near the starter you will see a hex head in the oil galley. If you follow the galley from the where the switch mounts, you will see that the raised area in the case right there is the oil galley. I don't know if the thread is a metric or standard 1/8 pipe thread.
You will need to remove all 34 bolts that hold the cases together. The oil pump will need to come out. I believe the bearing cap for the mainshaft needs to be removed also. The cylinder and the head do not have to be removed. I recently rebuilt my engine, and after I was finished, it started to leak oil at the seals, so I had to get new ones, pull the engine out again, and split the cases. It isn't that difficult. If you get stuck or scared, don't be afraid to ask any question here. Most everybody is willing to help. Some of these guys are pretty sharp.
Good luck. Let us know how it turns out.
Here are some pics of what I did to my engine.
http://community.webshots.com/user/john80sg

Announcement

Leftover dowel pin after engine rebuild

Leftover dowel pin after engine rebuild

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment