billfrombyron Posted August 15, 2008 Share Posted August 15, 2008 OK, I read through the service manual, thank you to original poster of the manual! It says to use SAE 20 oil, it also says that 10W30 can be used. It further states that other types of oil could be used to stiffen up the forks. Would 20W50 work? I am hoping to stiffen the forks on my XS360 up a bit. I don't like the sudden compression that they seem to have with me at the helm, my friend however doesn't experience this problem as he weighs about 50lbs less than me. They also rebound pretty damn quick too, I am positive its not a spring issue(well mostly) My weight is now a trim 203lbs and I am 6'4. Am I chasing a dead end in hopes that just a oil swap would cure my ills? The bike has 6,345 miles on it, and the manual says every 10K miles to replace the oil. I'm thinking the oil is 31 years old, so maybe its a bit overdue? And yet another question.....Can I swap the forks for some XS400 forks with front disc brakes? What would be involved beyond the forks, and a rim and the hydraulics? Thanks -Bill Link to comment Share on other sites More sharing options...
Moderator drewpy Posted August 15, 2008 Moderator Share Posted August 15, 2008 what "spings" to mind, and I won't keep you in suspension, is that I use 20w fork oil and fill it 6" to the top of the tube. (forks fully compressed with the spings removed) The motor oil option performs badly as i belive that the oil foams and thus reduces it damping properties. wurth (german) and hagon (british) do an uprated progressive sping option if you want less dive. a 400 front end will fit yours if you want disks, but offer out the drum front end as lots of peeps are after those to do cafe racer/bobber bikes!! don't forget that you had a spoked front wheel and, unless you can get a 250 spoked front hub, you will have a front alloy wheel!! hope I didn't put a "damper" on things!! Link to comment Share on other sites More sharing options...
billfrombyron Posted August 17, 2008 Author Share Posted August 17, 2008 Well I have been advised by the Yamaha service shop here in town of a few things on the fork oil issue. 1)SAE30 will help with the problem I have been experiencing. 2)Nobody in my area sells 20W fork oil and I have been unable to locate a place online for it. I can find the heck out of some 10W or they advised me to use ATF fluid. I will NOT use ATF as it is the wrong grade. Its rated at 10W for what its worth. So I will try SAE 30W and see what it does. I went with a synthetic as it has anti foaming additives. Learned something else that is probably BS, but I will ask anyway.... Will using motor oil for a car harm the clutch in these bikes? According to the place I was at today if it doesn't have the MA grade rating on it its bad. He said that anything marked other than MA grade will supposedly have anti friction additives that will kill the clutch. Is this just an excuse for him to try to sell me some 30 buck quart of oil, or is it true? As to the front end after I do the XS400 swap it will not be for sale as I want to be able to have a spare should the unlikley occur. -Bill Link to comment Share on other sites More sharing options...
billfrombyron Posted August 17, 2008 Author Share Posted August 17, 2008 Well gents, It needs a bit more road testing tomorrow, but it seems as though the problem is now cured! I will let y'all know how the straight grade motor oil fares. BTW the oil I drained out was GREEN, followed by what smelled like chain saw bar oil. Suffice to say I flushed it real good. If the manual says that straight grade 20 motor oil is OK, then it must be OK right? I went with 30, but I was looking to stiffen it up just a smidgen. It worked wonderfully for me at my height/weight range. -Bill Link to comment Share on other sites More sharing options...
road_rascal Posted August 17, 2008 Share Posted August 17, 2008 I'm not sure how the forks are put together on your '77 (or my '82 for that matter- not yet at least), but you may want to try this procedure: http://www.vmaxoutlaw.com/tech/fork_stiction_tuning.htm I did this with my '97 Nighthawk and (now gone) '82 KZ750. It made a huge difference on how the bike handled. I'm going to tear apart the forks on my Maxim within a month or so and I'll probably do the same. Strange that you can't find a cycle shop with different grades of fork oil. I just purchased 10W for my Goldwing and 15W for the Nighthawk (Motul brand). Link to comment Share on other sites More sharing options...
Moderator drewpy Posted August 17, 2008 Moderator Share Posted August 17, 2008 I'm not sure how the forks are put together on your '77 (or my '82 for that matter- not yet at least), but you may want to try this procedure: http://www.vmaxoutlaw.com/tech/fork_stiction_tuning.htm I did this with my '97 Nighthawk and (now gone) '82 KZ750. It made a huge difference on how the bike handled. I'm going to tear apart the forks on my Maxim within a month or so and I'll probably do the same. Strange that you can't find a cycle shop with different grades of fork oil. I just purchased 10W for my Goldwing and 15W for the Nighthawk (Motul brand). you can actually mix different grades of fork oil to get another grade ie 10w + 30W to get something between 10 and 30 depending on the ratio's. BTW dont ask I don't know the ratios Link to comment Share on other sites More sharing options...
Moderator drewpy Posted August 17, 2008 Moderator Share Posted August 17, 2008 Will using motor oil for a car harm the clutch in these bikes? According to the place I was at today if it doesn't have the MA grade rating on it its bad. He said that anything marked other than MA grade will supposedly have anti friction additives that will kill the clutch. Is this just an excuse for him to try to sell me some 30 buck quart of oil, or is it true? As to the front end after I do the XS400 swap it will not be for sale as I want to be able to have a spare should the unlikley occur. -Bill bike oil is specifically blended for bikes, and has different properties than motor oil which has a much easier time over longer service intervals. I'm asuming that, because it is produced in much smaller quantities, it tends to be more expensive. Link to comment Share on other sites More sharing options...
billfrombyron Posted August 17, 2008 Author Share Posted August 17, 2008 So the oil I purchased I should now drain out and fill it with the special oil, MA grade at $30 per quart? Or am I ok as is? -Bill Link to comment Share on other sites More sharing options...
Moderator drewpy Posted August 17, 2008 Moderator Share Posted August 17, 2008 So the oil I purchased I should now drain out and fill it with the special oil, MA grade at $30 per quart? Or am I ok as is? -Bill i'd change it after 1500 miles along with a oil filter Link to comment Share on other sites More sharing options...
Gnash Posted August 20, 2008 Share Posted August 20, 2008 I'm not sure where you live, but I found Castrol MOTORCYCLE oil at Orielly's in my very small town, here in Missouri. Just go to your local auto parts store and you should find some. Be sure and mention 4 stroke oil. Link to comment Share on other sites More sharing options...
G-man Posted August 20, 2008 Share Posted August 20, 2008 Learned something else that is probably BS, but I will ask anyway.... Will using motor oil for a car harm the clutch in these bikes? According to the place I was at today if it doesn't have the MA grade rating on it its bad. He said that anything marked other than MA grade will supposedly have anti friction additives that will kill the clutch. Is this just an excuse for him to try to sell me some 30 buck quart of oil, or is it true? That's true for 10w30 oil. 10w40 and above doesn't have those additives. Link to comment Share on other sites More sharing options...
G-man Posted August 20, 2008 Share Posted August 20, 2008 Whoops, double post. Link to comment Share on other sites More sharing options...
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