71 250 Scrambler Fork Issues...

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lumbee
Posts: 7
Joined: Mon Sep 10, 2012 2:32 pm
Location: Asheville, NC

71 250 Scrambler Fork Issues...

Postby lumbee » Mon Sep 10, 2012 2:42 pm

Hey guys, I have a 250 scrambler, and am having issues with the front forks. The spring/rebound on them is really rough. For instance if I hold the front brake and lean forward to compress the forks, they will actually 'hang' after being compressed a few inches, and I have to pull back on the bars to get them to rebound.

I pulled the forks out of the trees and disassembled one of them (one is really bad...the other not so much..but its not great). All of the parts seem to be there, however there was no oil in either shock. All the compnents seemed to be in good shape...no rust at least. I added fork oil and reassembled and there is no much difference in the rebound/smoothness.

So I was wondering if anyone had a diagram/scematic of the forks for the scrambler, just to make sure all the parts are there.

My other question is, I was able to disassemble the internals of the fork, but I did not separate the upper and lower portions fork tubes. I removed the clip, but the forks did not seem to want to slide apart. Once the clip is removed is the seal the only thing keeping the upper and lower tubes together?

Any info appreciated. Thanx!
71 250 Scrambler
6x 160 Monza Jr.

Eldert
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Location: Hazerswoude Rijndijk Netherlands

Re: 71 250 Scrambler Fork Issues...

Postby Eldert » Mon Sep 10, 2012 3:17 pm

http://www.ducatimeccanica.com/marzocch ... /index.htm

looks like a 38 mm fork to be but the differances between the 35 and 38 mm forks are very small

on the bottom of the forkslider there is a M 12 allanbolt holding the slider to the damperrod

Eldert

lumbee
Posts: 7
Joined: Mon Sep 10, 2012 2:32 pm
Location: Asheville, NC

Re: 71 250 Scrambler Fork Issues...

Postby lumbee » Mon Sep 10, 2012 3:30 pm

...awesome link Elbert. This was exactly what I was hoping to find. I have the Clymers manual for singles, but there are not any good scematics of the forks...this looks to be pretty close to mine...

http://www.ducatimeccanica.com/marzocch ... chi_05.htm

Actually looking at that diagram I think the components may not be in the correct order. I will check that out this afternoon. Thanx!
71 250 Scrambler
6x 160 Monza Jr.

lumbee
Posts: 7
Joined: Mon Sep 10, 2012 2:32 pm
Location: Asheville, NC

Re: 71 250 Scrambler Fork Issues...

Postby lumbee » Mon Oct 01, 2012 12:09 am

Hey guys, I am still dealing with fork issues on my 7x 250 scramler. The symptoms are the shocks bearly spring back when compressed. I have taken them apart a few times, and everything seems to be in order. I also addded the correct amount of fork oil. Here is a pic of the dissembled fork.

https://lh4.googleusercontent.com/-9B0H ... 27_909.jpg

Does it look like all the parts are there to you guys? Also, the way I have it laid out, is how I have assembled it. Does this look right?

I still have not separated the upper and lower forks from one another. There is no bolt on the underside of the lower fork like some have suggested. There is a cir-clip that holds the seal in place, and I am thinking I could remove that, and they could come apart.

Also, I have still yet to find a diagram of this particular fork, if anyone has one please post a link. Thanx!
71 250 Scrambler
6x 160 Monza Jr.

ajleone
Posts: 231
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Location: Pittsford, NY
Contact:

Re: 71 250 Scrambler Fork Issues...

Postby ajleone » Mon Oct 01, 2012 1:25 am

It might be a Telesco fork, which came on the Spanish Mototrans bikes. I think there is a parts book for tis on the sight.
Tony

amartina75
Posts: 347
Joined: Tue Aug 21, 2012 1:13 am
Location: Cincinnati, OH. USA

Re: 71 250 Scrambler Fork Issues...

Postby amartina75 » Mon Oct 01, 2012 4:50 am

you could have a bent fork tube or lower leg. that could cause the forks to hang up as you say. i have never taken apart a set of forks like you have but all of the marzocchi, cereani, betor and jap forks i have seen have a bolt on the bottom that threads into the dampening rod. i dont see why those would be any different. you need to get them apart and inspect them to see if they are bent anywhere. roll the fork tubes together and see if there is a gap between them if there is they are bent. also sight down the legs and see if they look straight.
good luck
1966 250 Scrambler
1970 450 Jupiter

graeme
Posts: 1010
Joined: Sun Mar 25, 2012 12:00 am
Location: Tasmania Australia

Re: 71 250 Scrambler Fork Issues...

Postby graeme » Mon Oct 01, 2012 7:08 am

+1on something bent.
Can you post a picture of the bottom of your fork inner and outer please?
There has to be something stopping the forks comming apart when you do wheel stands?
I'm not familiar with scrambler forks, but I would assume they are similar the later Marzocchi and Ceriani?
Graeme

lumbee
Posts: 7
Joined: Mon Sep 10, 2012 2:32 pm
Location: Asheville, NC

Re: 71 250 Scrambler Fork Issues...

Postby lumbee » Mon Oct 01, 2012 12:45 pm

..thanx guys. I don't think anything is bent on either fork. Both the forks have this similar resistance on rebound. With everything dissasembled the way they are now, the uppers/lowers slide smoothly. When they are assembled, and I compress then, it 'feels' more like the springs, or internal parts are hanging up.

I will snap a pic of the bottom end of the lowers and post it here.
71 250 Scrambler
6x 160 Monza Jr.

Jon Pegler
Posts: 471
Joined: Sun May 16, 2010 6:19 pm

Re: 71 250 Scrambler Fork Issues...

Postby Jon Pegler » Mon Oct 01, 2012 6:05 pm

Your photo of a dismantled fork leg shows that it is certainly a Telesco unit.
These forks have a screw on collar at the top of the slider that has to be unscrewed before the slider comes away from the stanchion.
The screw on collar usually comes undone fairly easily, but it can be a bit difficult holding it without damaging things.
Try holding the slider in a vice and using either a strap wrench or possibly pipe grips to get it moving.

Jon

amartina75
Posts: 347
Joined: Tue Aug 21, 2012 1:13 am
Location: Cincinnati, OH. USA

Re: 71 250 Scrambler Fork Issues...

Postby amartina75 » Mon Oct 01, 2012 10:09 pm

when you get them apart inspect all of the parts for wear and see if anything is bent, look for any signs of wear on the damper valve and rod, look for wear on the tubes, if a tube is slightly bent it can rub on the inside of the fork leg and also bind. if the chrome is worn at the bottom of the tube it is rubbing somewhere, and is bent. you should be able to find something that is bent or worn funny or they should work, even if they were assembeled completly wrong and could never be used on the road, they shouldn't bind or stick all of the parts are linear and just go in and out like a piston in a cylinder.
1966 250 Scrambler
1970 450 Jupiter


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