1975 R90/6
Is it conceivable that I have been riding with very nearly NO oil in front forks without really noticing? I just pulled the nuts of the bottom and pushed up on the rod until the dripping stopped. There was no more than a small puddle under each side.
What would be the impact on handling to run without oil? I had no apparent stiction, although I did not use a ruler to check.
Forked again
-
Major Softie
- Posts: 8900
- Joined: Tue Aug 03, 2010 1:46 pm
Re: Forked again
No damping. The forks should actually be more compliant when almost out of oil, but would like to pogo.
MS - out
Pilot error
I started refilling and at about 200 cc it overflowed.
So - I got out the book and read the instructions for the first time in a couple years. When I did it right - oil ran all over the damn place and I didn't get it measured.
Oh - well - I still have enough oil to do the job. So on to the next question.
Why is the BMW oil 7 weight and the book calls for 3 weight.
So - I got out the book and read the instructions for the first time in a couple years. When I did it right - oil ran all over the damn place and I didn't get it measured.
Oh - well - I still have enough oil to do the job. So on to the next question.
Why is the BMW oil 7 weight and the book calls for 3 weight.
1975 R90/6
1979 R65
1979 R65
Re: Forked again
My method to determine the amount of forks oil is to measure.
Fill to 6" from the top of the fork tube with the forks compressed and spring removed.
Success of any method depends upon pumping the forks to remove all old oil
and the verification of thoroughly CLEAN & CORRECT components,
Let's assume that the 7-wt BMW fork oil might be a standard
for BMW motorcycles built and sold during the current decade.
Having said that, I have most often used 5 or 7-wt in airheads.
Fill to 6" from the top of the fork tube with the forks compressed and spring removed.
Success of any method depends upon pumping the forks to remove all old oil
and the verification of thoroughly CLEAN & CORRECT components,
Let's assume that the 7-wt BMW fork oil might be a standard
for BMW motorcycles built and sold during the current decade.
Having said that, I have most often used 5 or 7-wt in airheads.
-
the quinner
- Posts: 112
- Joined: Thu Jun 02, 2011 10:53 am
- Contact:
Re: Pilot error
I changed fork oil in a customer's bike...not much came out of the right fork leg. I re-filled and didn't think much about it. On the test ride, I noticed purple fluid on the gas tank...the fork oil was blowing out the top on the right side...bbelk wrote:I started refilling and at about 200 cc it overflowed.
So - I got out the book and read the instructions for the first time in a couple years. When I did it right - oil ran all over the damn place and I didn't get it measured.
Oh - well - I still have enough oil to do the job. So on to the next question.
Why is the BMW oil 7 weight and the book calls for 3 weight.
...there was enough gunk gunking up the innerds of the right leg that the fluid would go UP through the damper, but was prevented from returning. Essentially, the damper was acting as a one-way valve.
I took the fork leg completely apart and found the gunk and the missing fluid.
-
Duane Ausherman
- Posts: 6008
- Joined: Thu Aug 12, 2010 12:39 pm
- Location: Galt California
- Contact:
Re: Forked again
To push up on the bolt to allow the oil to flow out won't work. It is too slow and sometimes it won't come out. Just use the method shown on my website and be done with it quickly.
Ask the Indians what happens when you don't control immigration.
Re: Forked again
Link! Where is the Link! I have of course cruised through your website as I am sure most of us have - but the time it takes to re-access those brain cells (WTF is the name of that site again) - the urge has passed and I just depend on the lessor sources like Heynes.Duane Ausherman wrote: Just use the method shown on my website and be done with it quickly.
Something like: http://w6rec.com/duane/bmw/forkseal/index.htm
I am sure Rob could tell me how to use words around that link to say whatever I want like "Duanes Forking Knowlage" instead of all that other stuff.
w6rec is NOT Intuitivly Obvious.
1975 R90/6
1979 R65
1979 R65
-
Duane Ausherman
- Posts: 6008
- Joined: Thu Aug 12, 2010 12:39 pm
- Location: Galt California
- Contact:
Re: Forked again
I am sorry that you have trouble finding stuff on my website. That is why I have a Google search bar on the BMW index page.
Indexing those articles has always been a hassle. I have tried a few methods of listing them, but each has been criticized. We each think differently, so we expect the 200 articles to be listed in the way our own brain works. I know that I do when I visit a site.
I too can't quickly find things on my own site, so I use Google.
If I can find my FrontPage software, I will start working on my site this spring, if I am not yet working. I really do want to get back to it, as I have a lot of additional information to add.
Keep in mind that I don't charge for the info. I don't even allow others to pay me to put ads on pages. I get offers, but reject them out of hand. I don't want anybody to question if I am getting paid to put positive information about a product, or service.
Indexing those articles has always been a hassle. I have tried a few methods of listing them, but each has been criticized. We each think differently, so we expect the 200 articles to be listed in the way our own brain works. I know that I do when I visit a site.
I too can't quickly find things on my own site, so I use Google.
If I can find my FrontPage software, I will start working on my site this spring, if I am not yet working. I really do want to get back to it, as I have a lot of additional information to add.
Keep in mind that I don't charge for the info. I don't even allow others to pay me to put ads on pages. I get offers, but reject them out of hand. I don't want anybody to question if I am getting paid to put positive information about a product, or service.
Ask the Indians what happens when you don't control immigration.
-
Zombie Master
- Posts: 8821
- Joined: Sun Aug 22, 2010 12:21 am
- Location: Vancouver Island BC Canada
Re: Forked again
"I am lazy and cheap and will go for the longer life."Duane Ausherman wrote:I am sorry that you have trouble finding stuff on my website. That is why I have a Google search bar on the BMW index page.
Any and all disclaimers may apply
-
DucatiPete
- Posts: 257
- Joined: Sun Aug 15, 2010 3:10 am
Re: Forked again
Thank you very much for your site, Duane - from the bottom of my oil pump...
bbelk: careful of that drain plug at the bottom of the fork - break that little sucker and your walkin 'till ya gets a new one... see my post from yesterday for evidence of this newly acquired wisdom.
And if you ain't been in there for a while I reckon it's a fair bet those bottom bumpers will have the consistany (and structural integrity) of a birthday candle!
good luck with the fill/rebuild and please keep us posted if any other issues arise - I'll be doing the exact same job when the new drain plug arrives.
pete
bbelk: careful of that drain plug at the bottom of the fork - break that little sucker and your walkin 'till ya gets a new one... see my post from yesterday for evidence of this newly acquired wisdom.
And if you ain't been in there for a while I reckon it's a fair bet those bottom bumpers will have the consistany (and structural integrity) of a birthday candle!
good luck with the fill/rebuild and please keep us posted if any other issues arise - I'll be doing the exact same job when the new drain plug arrives.
pete