Larry Perkins was right, I was wrong.

[dirtbike]

The following wrote Larry Perkins to me whan I claimed that plain ball bearings would work just as well as M25 magneto bearings. I was wrong and he was right. I has seized and the bearing cages did spread all over the crankcase ruin everything.

Larry P wote:
"This is is one of those debates that comes up again and again here and generally goes on and on each time. Here is the bottom line without 20 experts with a gillion years experience having to say it for the umpteenth time:

The self aligning bearings when properly installed and shimmed are the way to go. The normal style bearing WILL NOT WORK LONG TERM WITHOUT CAUSING GRIEF TO THE CRANK OR The CASE OR BOTH.

The regular ones DO NOT FUNCTION AS WELL, LAST AS LONG, NOR WAS THE ENGINE DESIGNED FOR THEM.

There is one reason and one reason alone that people try to make them work and find reasons they should work. THEY ARE CHEAPER! So were Yamahas so if you want that type of bearing a Japanese bike might be in order.

Now you can listen to your buddy or the advice of long term experience. Good Luck to you either way.

Hope this is not too harsh-JUST THE TRUTH."

[firstturn]

Larry is good and has been at it a long time on a limited budget, but his bikes were and are first class.

Score
Larry Perkins 1
Dirtbike      0

Great post[8D]




Ron Carbaugh

[Larry Perkins]

I wrote that post in my pissed off period and did not answer it very nice.  Sorry about that but even sorrier that I was right and something shelled.  Best of luck getting her going again.

Larry P

[dirtbike]

Actually, I sold the bike and heard this from a mutual friend. Anyway, I told the buyer clearly what went on with the bearings so he was fully aware of the mod.

So, anyone out there who have read my earlier posts and decided to give it a go, don't!!

[tomale]

Larry, I know you can come across as harsh, but it is only because you feel strongly about the subject. Everytime you post anything I read it only because I know I am going to get the straight scoop. and as for your personality, I found you to be a joy to talk to. I still to this day remember our brief converation at the ISDT RR a few years ago. It is a high water mark...
 I live so far west that most of you guys I never get to rub shoulders with... but once in a great while.
There are less than a handful of penton riders here in the Northwest.. There is rarely more than one Penton at the races and there have been times when there were no Penton at all for a year or better...I can hear it now, why not mine? well because the only time I get my Pentons out is for CC races and there are very few of those in this part of the woods.. I love my Penton but I think it is best suited for woods riding.. It is just does not give up.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)
72'sixday (project bike)

[sachsmx]

I know a lot of guys who are using a standard ball bearing or newer style KTM roller bearings in their 420s and 495s. I wonder if the results will be the same in the slower revving bikes, especially the standard ball bearing? I took no chances and sourced true NOS M30 bearings. They were expensive at $125 each, but when I did the math and figured a race ready engine was going to cost nearly 2 grand to build (all new bearings throughout, piston, overbore, etc, etc)I wasn't about to cut corners.

[dirtbike]

sachsmx, I know people using those bearings too. I belive that it could work but it could also fail. Probably it's a chain of circumstances that, when lined up could cause disaster.

I won't do it again though, that's for sure...