Checking out New Engine

[cywelchjr]

An update on checking out my replacement engine this weekend. Well, it didn't happen. Not having a garage or even carport to work in, and with the driveway right out in the sun, the 100+ temps this weekend put paid to working on the motor. Hopefully next weekend will be more normal for this time of year and I can crack the cases and check the bearings and the gears.

Ok, here is the question I have, I'm pretty sure that on the mains I would look at the bottom shells for wear since that is the direction of wear force, but what and where do I look on the rod bearings? I'm assuming I need to remove the caps on them, should I plastiguage them or should I do a visual check on them?

Also, what types of sealant work well in place of yamabond, or must I use yamabond. I want to make sure it's going to seal well when I put it back together as SWMBO gets upset with puddles of oil in the driveway, not to mention pulling forward and running the rear tire through a pudding on the way out of the driveway is contrary to good handling .

Thanks for the help and advice I've gotten from the site so far, although with the relatively minor problems I have had with the bike so far I'm feeling pretty lucky. If only the stupid original engine didn't have a knock, as it's stopped burning and leaking oil now after only 2000 miles, but that darn knock has me really nervous (don't know if it's piston slap, wrist pin or bearing, but it doesn't seem to be getting worse hardly at all).

[bikerphil]

[QUOTE=cywelchjr;209899] that darn knock has me really nervous (don't know if it's piston slap, wrist pin or bearing [QUOTE]

What RPM is the knock at? Is it at cruising speed or hard throttle? What weight oil are you using?

[trbig]

The rod bearings almost never go bad. I wouldn't worry about checking them.. especially since it's only going to be used a couple years as you said.

The Yamabond and Tribond are good stuff. It seals well and stays rubbery through the years and temps.

When you split the cases, the bottom shell is actually what you take off. The crank will still be in the top half that is upside down. Generally, what you see on the bottom shells is what you'll see on the top. If you are worried about leaks, the crank seals are a cheap easy fix to replace 25+ year old rubber seals. You can do it later if you want, but it does require you removing the rotor.. which can be a major PITA sometimes.

The oil pan, cam chain adjuster, and valve cover tend to be the leak culprits. Getting the cases sealed is usually pretty easy. Unlike Harley that made their case halves vertical which help it leak, the XS seams are horizontal. The oil basically sits in a bathtub in our bikes and only has to be guarded against splashes... not submergence. Take your time and run a good thin bead.. it doesn't take much besides a continuous bead. I have never had one leak yet from the cases.(Knocking on forhead)


Tod

[cywelchjr]

[QUOTE=bikerphil;209909][QUOTE=cywelchjr;209899] that darn knock has me really nervous (don't know if it's piston slap, wrist pin or bearing

What RPM is the knock at? Is it at cruising speed or hard throttle? What weight oil are you using?

I can hear the knock at idle and then again above 3k. In addition at 3k the valve noise goes way down. Of course the noise goes way down when fully warm anyways.

[cywelchjr]

[QUOTE=bikerphil;209909][QUOTE=cywelchjr;209899] that darn knock has me really nervous (don't know if it's piston slap, wrist pin or bearing

What RPM is the knock at? Is it at cruising speed or hard throttle? What weight oil are you using?

I just realized I didn't answer the whole question. The knock is noticable at idle and then resurfaces above 3k. I'm using 15x40 Rotella with some seal revitalizer added (half the bottle, it did stop the drips from the seals quite well). I'm trying to figure out how to get video and audio of the knock to post on u-tube, but I'm not sure yet how I'm going to accomplish it.

I'm also about due for an oil change so I'll be checking for particulates in the oil and the filter. I've got just a bit over 2k on this oil change, and for the first 1.5k I went through about a cup of oil per week (about 160-200 miles of driving) and in the last 500 comsumption seems to have dropped off almost completely. I know it sat for a least a month right before I bought it, and the PO had it about a year, so I don't know how long it sat before he bought it, or what additives he put in there (I didn't hear any knock when I test rode it, and the first I noticed the noise was after changing the oil).

I didn't get the replacement engine cracked open this weekend, 100+ with no shade, carport or garage just made it not to be done, so hopefully this weekend I'll get the engine checked out and the knock in the original will be moot.

I guess after I get this engine out, I'll find out for sure what's wrong with it. and maybe I'll be shocked that it didn't leave me stranded.

[trbig]

Most things tick or tap in the top end. A knocking in these motors usually indicates crank/bearing problems. My first motor that knocked.. had spun a bearing and ruined the engine block and crank. The second motor I had that had a knock... I split it and put all new crank bearings in and rode it... about 3k miles before it got really bad again. I split the cases again to find those new bearings had been wiped out. So apparently the crank was WAY out of spec to begin with.

Just a side note though... that first motor that had spun a bearing... did so on the way to my first rally here in Oklahoma. I ended up making it the rally, riding all day Saturday and riding home carefully Sunday over 100 miles. I ended up having to ride home @ 45 mph.. but the bike did get me home.

My point is.. it will probably still get you where you need to go, but knocks and leaking crank seals generally point to bad crank/bearings. I wouldn't count on having a rebuildable motor afterwards, but hopefully I'm wrong.


Tod

[bikerphil]

Cy, for what it's worth, I had a 79F motor that had a knock similar to what you are describing. I ended up running straight 70W Harley oil in it, and that made the knock almost go away, even when hot. I got over 25K on it that way and it just wouldn't quit. I ended up tearing it down after finding a low mile replacement motor, and the bearings looked worn but not totally trashed. For the time being, you might want to try an oil thicker than 40W.

[fossil]

sealent

Just a note: If you seal up the engine, don't let anyone talk you into using RTV. You know how it squeezes out on the out side? It does the same on the inside and can come loose and find it's way to the oil pick up and if there is enought of it the pick up gets plugged.