Since the forks on a 76 MR are a good deal smaller than the 78 CR, I would say no.
I'm pretty sure the oil viscosity is the same but I'm guessing the quantity is going to
be less.
Hey Ray, another MR question.
dogger
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| 1978 CR250R Fork oil capacity? https://vintagedirtbikeforums.alp-sys.com/viewtopic.php?f=21&t=2251 |
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| Author: | SFx73 [ Thu Apr 16, 2009 7:52 pm ] |
| Post subject: | 1978 CR250R Fork oil capacity? |
I'm replacing the fork seals on my '78 CR250R and need to know the amount of OZ's or CC's to put in each leg. I tried the "Search" and had no luck. Also, I'll be using 20wt. fluid. Thanks for any info. |
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| Author: | dogger315 [ Fri Apr 17, 2009 9:42 am ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
275cc per leg. 20 wt is quite a jump from the 5 wt specified. dogger |
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| Author: | SFx73 [ Fri Apr 17, 2009 12:12 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Dogger315, thanks for the info. I'm kind of new to the vintage scene and a couple of guys recommended 20 wt. Maybe because I'm heavier (235 lbs.) than the average rider, but I did use stiffer springs from Vintage Iron. What would I notice between 5 wt. and 20 wt. ? Thanks again. |
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| Author: | dogger315 [ Fri Apr 17, 2009 4:36 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Suspension tuning is something you kinda have to sneak up on. I like to establish a baseline with stock settings. I record this information so I always have something to return to if my testing gets me going in the wrong direction. I keep a log and record every change and what it does or doesn't do. If you race more than one track, this info can be a big help. For years, Honda spec'd the suspensions on the 250s for the "mythical" 165 lb intermediate rider. For many, this meant the suspension was too soft and easily bottomed out. Using heavier fork springs is a good idea. Upping the oil viscosity three grades over stock may make the forks too stiff and also too slow to rebound. Since it is easy to change fork oil, I recommend you start with 10 wt along with the heavier springs. Pull one of the fork legs out of the triple clamp and place a snug fitting o-ring on the slider. Button everything up and put in a couple of hot laps noting how the bike handles and feels. Then take a look at the o-ring to see how much travel you used. This is the sneak up part I was talking about. You can fool around with the oil viscosity and the oil amount to "tune" the forks to your weight and speed. Another device that might help is a set of air caps. This will give you one more way to fine tune. There is also a good article in the reference section by "Red Rocket 190" detailing how to add a little plushness to the fork action. Remember, whatever you do to the front, you will have to do to the back to maintain balanced handling. This is the "testing" portion of racing motocross. This is what the fast guys with the big salaries do all week long and why they usually finish the season with a much better bike than they started with. dogger |
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| Author: | redrocket190 [ Fri Apr 17, 2009 10:45 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Check out the Al Baker mod specified in the CR Reference section... |
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| Author: | rayivers [ Sat Apr 18, 2009 4:49 am ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
How do you access the CR Reference section? Ray |
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| Author: | redrocket190 [ Sat Apr 18, 2009 9:35 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
http://www.honda-elsinore.com/ Click on Reference.... |
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| Author: | SFx73 [ Mon Apr 20, 2009 7:39 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Thanks for all the help and information. |
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| Author: | dsmtuned [ Wed Jun 03, 2009 7:54 pm ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Any idea if the above listed capacities are the same for the fork of a 1976 MR250? Same weight oil as well? -Thanks, Craig |
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| Author: | dogger315 [ Thu Jun 04, 2009 10:03 am ] |
| Post subject: | Re: 1978 CR250R Fork oil capacity? |
Since the forks on a 76 MR are a good deal smaller than the 78 CR, I would say no. I'm pretty sure the oil viscosity is the same but I'm guessing the quantity is going to be less. Hey Ray, another MR question. dogger |
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