Author Topic: Engine/tuning issues  (Read 7961 times)

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Arizoni

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Reply #30 on: November 04, 2012, 01:22:34 am
"...I always start with the simplest and never overlook the  obvious...."
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You mean like the time I sit there looking at the end of the rear motor mount stud for a minute and then said, "Whoa!  Isn't that supposed to have a nut on it?  It looks like it sheared off!"  :(

 ;D
Jim
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LarsBloodbeard

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Reply #31 on: November 04, 2012, 06:15:41 am
Yes, it will take quite a number of miles before those rings are fully bedded-in.
The basic sealing gets done early, but the rest of it takes quite a few miles.
Idling won't do it. You need to load the rings up with some acceleration and deceleration with some real road riding. You don't have to rev it way up or be hard on it. Just give it some loading on some hills and stuff, at moderate speeds.
That will help. You are probably running on lower compression than you expected, until the rings seat better.

What I'm hearing is I should take it out on the Norton ride tomorrow... :)

Oh and I checked the compression today too.  It was 90, but I forgot to open the throttle when I did it.

Regarding the shakes: I wouldn't be surprised if something terrible is going on with the crank.  Just about every component was in awful shape when I got this bike.  However, I took it on a test ride later today and heard a loud clatter at certain RPM's that scared the wallet out of my pants.  Poked around and discovered the head stay was loose, just like baird guessed.  Oops!  Guess I neglected to torque that down.  :P  The shaking is reduced, but still very prevalent.

Anyway, I think I'll just plan on ordering a new crank and bearings in a month or so.  In the meantime I'll break it in and hope for the best.

As usual, thanks for all the advice, guys.
« Last Edit: November 04, 2012, 06:17:45 am by LarsBloodbeard »


ace.cafe

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Reply #32 on: November 04, 2012, 09:00:19 am
A word of advice about the bottom end.
You need very good bearings from a known top brand bearing company. OEM bearings really are not up to the grade.
When you get the crank, you cannot assume that it is trued. Even if it was trued at one time, that is no guarantee that it will arrive at your house in trued condition. Shipping often knocks them out of true. It would be VERY advisable to use dial-indicators and v-blocks or a lathe to check that it is under .002" run-out total.

Next, if you plan to build this bike beyond stock at all, you need to address the con-rod problem when you do the bottom end rebuild. The con-rod in the 500 is generally not  best-suited for handling higher power or more rpms.
My usual advice is that if you are going to go through all that work of a bottom-end rebuild, then build it up as strong as you can, and do it once, so you don't have to go in there again for a long time.
« Last Edit: November 04, 2012, 03:43:44 pm by ace.cafe »
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LarsBloodbeard

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Reply #33 on: November 04, 2012, 08:50:05 pm
A word of advice about the bottom end.
You need very good bearings from a known top brand bearing company. OEM bearings really are not up to the grade.
When you get the crank, you cannot assume that it is trued. Even if it was trued at one time, that is no guarantee that it will arrive at your house in trued condition. Shipping often knocks them out of true. It would be VERY advisable to use dial-indicators and v-blocks or a lathe to check that it is under .002" run-out total.

Next, if you plan to build this bike beyond stock at all, you need to address the con-rod problem when you do the bottom end rebuild. The con-rod in the 500 is generally not  best-suited for handling higher power or more rpms.
My usual advice is that if you are going to go through all that work of a bottom-end rebuild, then build it up as strong as you can, and do it once, so you don't have to go in there again for a long time.

I will definitely follow your advice when the time comes.  According Hitchcock's, the modifications I made aren't supposed to stress the stock components too much.  I would like to do a bit more though.  Ported head, better performing cams, etc.  Nothing real crazy.


LarsBloodbeard

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Reply #34 on: November 05, 2012, 08:00:57 pm
Problem solved!

I replaced my coil and spark plug, and as soon as I fired it up it ran great.  Tweaked with the idle screws a tiny bit but that's all.  It now will idle really slow and smooth.  Thump........ Thump.......  Thump.......