Yamaha WR250R Mega Thread

[trav72]

Originally Posted by skierd

X change complete! Found the tab, thanks trav.

Can't believe how different it rides now, much smoother and much faster and lighter steering. Suspension feels like it works better too. I think im gonna like it, like a whole new bike now.

Glad you got it! Don't you love how much different it feels on the road? Just like you said, it's quicker and the turn in is so much faster. I'm so happy I have the X wheels to put on when I'm using it for street duty. We'll have to go for a ride sometime since you're relatively close to me.

[trav72]

After Jagers post about his chain eating into his swingarm, I decided to check mine. I've been meaning to do it for a while but kept putting it off. I pulled my slider and found some wear. Not as bad as Jagers obviously. But still significant enough to park the bike until a new slider arrives before the damage is worse. Here is what I found.

8600 miles worth of wear. 2000 of which I was running a 12t sprocket.


The chain has made contact with my swingarm. A small rub mark that's slightly gouged. Nothing really to worry about once the new slider is installed.

[GotMojo?]

I thought the whole chain eating into the swingarm thing was caused by running the chain too TIGHT, not too loose. I think BigDog discovered this similar problem on his WR250R and now he specifically says on his website that he runs the chain looser than the manual says so that it doesn't wear into the guide at all.

[HighFive]

Originally Posted by madisonreid

Service tech is having difficulty with Safari tank secondary pump to move fuel to primary. It worked on original install and does not allow for bike to turn over. Any thoughts ?

If it has been run dry, the secondary pump may have lost its "prime". If you used a Tee fitting to tap the vacuum line, you can help re-establish its prime by temporarily diverting all vacuum force to the secondary pump....i.e. block off the vacuum to the other direction (flapper, etc), if applicable. Just slide a temporary vacuum plug onto the Tee fitting where needed.

Meaning....make sure 100% of the vacuum is going to the secondary pump. You will need to fill the gas tank at least 1/2 full to get this going properly again.

If none of that is effective, you may have a bad secondary vac-pump. Though, these little Mikuni pumps are pretty reliable (if you haven't messed with them....i.e. taken apart and reassembled).

HF

[trav72]

Originally Posted by GotMojo?

I thought the whole chain eating into the swingarm thing was caused by running the chain too TIGHT, not too loose. I think BigDog discovered this similar problem on his WR250R and now he specifically says on his website that he runs the chain looser than the manual says so that it doesn't wear into the guide at all.

That's probably what has saved my swing arm up to this point. I usually run my chain pretty loose. I know it's looser than what the manual says.

[Jäger]

Originally Posted by RichardU

Those are typically acquired in a process called a wedding.

I already have that behind me, although I did avoid the process until after my 50th birthday.

I really am pissed at myself about this, except I still can't figure out how I went from hero to zero in just a few weeks since the last time I was doing chain maintenance and checked.

That sounds like really fast chain wear. I agree with checking the chain thoroughly, and see the bike is riding low for any reason.

I'm as much on tippy-toes as I've alway been on the bike - still ignomously fall over sideways when I need a foot dab and the slope of the ground offers me nothing for support but air. Did that two days ago, in fact.

There's no doubt the chain is at the end of it's life cycle. But my pedestrian riding habits while gawking at the mountains and scenery means there's no broken sprocket teeth, no hooking, etc - nothing gross looking. Felt fine right up until I felt the chain skip on the sprocket yesterday. The intent was to run this sprocket chain until a few weeks before my Montana/Idaho trip this summer, then go to my intended 14/49 setup and a new chain.

Don't have a new chain to compare it to for feel and deflection, but it does seem to have an awful lot of side to side play in it. In any case, with this happening, the sprockets and chain change will be happening at the same time I do the swingarm repairs and service.

If I wanted to ride it without repairs, I would check it every five minutes to start with and increase the interval after I had a sense of what it was doing.

Once and if I leave camp, it's all or nothing, no inbetween. It's get all the way home or turn back. I rode it a couple of hundred yards with the chain again back at Yamaha spec - 8mm. I swear I could hear links "tink"ing off the swingarm. But by then I was probably hypersensitive enough to noise that I was probably just hearing memories of last year's rides.

From what I could see of the picture, it looked like filling it with liquid steel, JB Weld etc. would do the job.

I'm assuming and hoping it is no more than an ugly scar. I will make a feeler with a bent flagging wire tomorrow and scratch around the bottom of the worn parts. Hopefully I won't feel it drop into any cavities...

I've never done the JB Weld thing before and there's none to be found here. I guess I'll get my first experience with it, followed by some time with patterning files and a Dremel, once I get back home.

This is the reason I keep a spare chain slider.

Seal protector...

I guess I will now as well. I figured I'd have lots of warning as it got close, but it went from what looked like lots of meat left to this in just a couple of weeks

Originally Posted by andy mac

Possibly your chain has some tight links and you adjusted the tension to the loose links, therefore when the suspension compressed and the tight links rotated, the too tight chain began sawing into the swingarm slider (seal guard).

I suppose. I'm a mechanical klutz, so anything is possible. I'm going to guess it is unlikely, however, because I generally don't trust myself with tools and check everything I do again and again.

To tighten my chain, I loosen everything up, leave it on the sidestand, and then adjust the slack adjusters until it is at the slackest end of the recommended tension range - 8mm space between chain and swingarm at the midway point.

Once I'm happy tension is right, it goes up on the stand and I use a Motion Pro alignment tool to ensure the chain is correcly aligned. I spin the rear wheel a few times while doing this to ensure I haven't loaded the chain somehow or other. Then the slack adjusters get locked down. Then it goes back over on the kickstand to ensure the tension has not changed and is within adjustment specifications. Once everything still looks all good, a little dab of blue Locktite and I torque the axle nut down to the specified torque. A final check on tension and alignment to ensure there have been no shifts, and then the chain guard goes back on and I call it a day.

Seems it would be hard to adjust to a loaded part of the chain using that scenario.

Here's some part numbers and contacts -
JT front sprocket JTF1590SC-14
JT rear sprocket JTR245/2-49
Seal Guard swingarm 3D7-22151-00-00
Front sprocket nut (part number not phone number) 9079-18010
Chain 112 links

http://www.yamahasportsplaza.com/pages/OemParts 503-669-2000

http://www.servicehonda.com/

http://www.cyclepartswarehouse.com/default.asp 866-926-2427

Thanks a lot Andy.

Originally Posted by GotMojo?

I thought the whole chain eating into the swingarm thing was caused by running the chain too TIGHT, not too loose.

That has been the general concensus. However, if anything, this was caused by a chain too loose.

I was surprised when I felt the chain skip on the sprocket so quickly after the last adjustment. When I checked it this morning, the chain was so loose you could easily press one or two links up against the bottom of the swingarm. The front of my Sandman case saver had wear marks, presumably from the front sprocket spitting the chain against the case saver because of how loose it was. The axle nut was still tight enough it took the usual stomp on a small breaker bar to loosen it off from the factory torque specs, and the slack adjusters were all tight and properly in place.

I'm at a bit of a loss how this happened in the first place, and also happened so fast. I've been checking this area probably more often than anywhere else, precisely because numerous people have written about having this problem. I thought I would get ample warning things were about done, but obviously not.

Like to learn how this all happened so quickly, before this happens again.

[skierd]

I posted most of this in your WRR forum thread, but it should be put here too. Quick question, whats your mileage?

Long story short, I think the general consensus is wrong regarding slider wear.

The guy who swapped his X wheels with me earlier today, Josh, his X has ~6700 miles on it now and the slider looks barely worn. Almost brand new even, with a little wear at the pivot. Stock sprockets and chain, both in good shape. It kinda solidifies my theory that the terrain that you ride on, namely how often the swingarm goes above horizontal while riding at speed, determines the wear on your chain slider more than any other factor. His bike was mainly commuted on and never really worked, mine has probably bottomed out half dozen times in regular trail riding and gets works on a semi-regular basis but not as often as an aggresive rider who uses his or her WR250R as a plated dirt bike. Remember that the sprocket is above the pivot bolt for the swingarm, therefore any verticle motion of the swingarm above horizontal will drive the chain into the swingarm by necessity. The wear pattern supports this, as the majority of the wear is at the pivot followed by at the feed to the front sprocket at the front of the swingarm/slider. That section is only going to be in contact with the chain when the swingarm is above horizontal.

A 12T exacerbates the wear because of its smaller diameter causing the angle of attack of the chain at the swingarm pivot to the greater than the 13T, which in turn is greater than the 14T. Those of us who found excessive wear with a 12T probably found trails and rides that worked the suspension enough to cause the wear slowly with a 13T, but with the added angle with the 12T it gets worse. This scenario, where terrain matters most, is the only thing I can think of at the moment that would explain why lowered vs' stock height bikes doesn't show a dramatic difference, as everyone rides at a different level of aggression and on different types of terrain regardless of ride height, and why the various tensioning methods seem to have inconclusive results in regards to preventing chain slider wear.

So my point is, its likely more the fact that you beat up and down washboarded and otherwise shitty/fun roads and trails that causes your suspension to flex a bunch more and therefore wearing the slider than any inattentiveness to maintenance. Proper tension is still important for all the reasons its important (chain, sprocket, transmission life, etc) but I don't think it is the cause of the slider wear.

To add, some data points from my own experience. I have always set my chain tension the same way on both my WRR's: adjust it so that I can fit my index finger between the swingarm and chain on the underside about halfway between the chain guides and have the chain just barely touching my finger. I think it works out to 3/8" of clearance, but I don't remember how thick exactly my finger is off hand and no I'm not going to measure right now. My first WRR was never particularly punished off road and while it did a lot of traveling, I never did see the chain slider worn through. It ran a 13T and a 14T for its entire life until it was stolen with 17K miles. My current WR250R has been used for a lot of commuting and travel, but I have also gone out and used and abused it on trails, dual sport rides that were untimed enduro's, and lots of aggressive street riding but overall its usage would still be mild to medium in the relative scheme of things. Most of the aggresive riding was in the first 10k miles. I ran a 12T for about 6000 of that, during which time I wore through the stock slider. After changing the slider and sprockets to a 13/46 setup, except for one 120ish mile hard dual sport ride, its been all commuting and travel again. 17k on the current slider and its still going strong, about halfway to 3/4 worn. Most of my riding is on pavement, though a lot of it can be pretty bombed out and nasty in the city. If I rode there more often, or I rode on worse terrain more often, I'd gaurantee that my slider would be more worn.

CN: Its terrain, not tension, causing the chain slider wear imo. If you ride hard off-road or even just ride a lot of bad roads for a few thousand miles, budget $50 for the chain slider every here and again and keep an eye on it.

[Chadx]

It'll be interesting to see how this swingarm wear pans out and which theories prove to be the cause. I can see how both the too tight and too loose theories could be plausible. I think skierd might be onto something, though. Not only the terrain, but more importantly rider and packed weight. If the bike is squatting hard due to weight and pulling the chain up towards the guard, there isn't much suspension travel needed for the geometry to be such that the guard seal (chain slider) is contacted. This even if you adjust sag correctly since the spring is ideal for a specific range and many folks are running heavier loads (heavier person or running with heavy gear packed on). I'm 170lb and usually have at least 10 - 20 lbs of gear with me. A lot of my miles are fast, slamming terrain, but realistically, the majority are not punishing the suspension in any way. The 3,000+ miles that I ran the 12/43 sprockets didn't really wear much on my guard and the 13/48 doesn't much at all. I did replace it (with pictures and details somewhere in this thread) at a mileage I forgot. Maybe 8.000 miles? I have one laying here for my wife's bike, but with 13/52 sprockets and her weight less than me, there isn't much of any wear on there. [Edit: found it. My pictures and details are here: http://mrchadx.blogspot.com/2010/08/...placement.html ]

By the way, the part is listed as "seal, guard" so the correct phrasing is "guard seal" when we are talking about this part. Just like "cover, thrust" and "bolt, flange" are thrust cover and flange bolt. It's the usual way they list the parts with that comma in there. Chain slider seems more descriptive, though, and a more realistic name since this piece is not a seal. Maybe the comma was a mistake since seal guard would actually be more plausible than guard seal since there is a seal within the swingarm there (as well as bearings) and this would be guarding them against our chain digging through the swingarm to the seal. Maybe is was a matter of Japanese to English translation.

[kawagumby]

yep. Two things affect wear the most in my experience...the first is dirt and water - silicon is very hard and is abundant in dirt, water is the medium that delivers it into nooks and crannys - it grinds away at everything, and using a small front sprocket just makes things worse regarding grinding.
The second is the geometry of the chain and suspension. Ideally, the swingarm pivot point should be the center of the countershaft sprocket, but that is impractical, so it is placed as close as possible behind it. This means that the chain tightens as it moves either way up or down - when you bottom out your suspension on a hit, the chain is much tighter than when it is level.
If you are worried your chain might be too tight, you can compress the suspension to the max and see if the chain still has slack or not.


As an earlier poster noted, chains often don't wear evenly, and worn ones often have sections that are tighter or looser than others, which means you should rotate the chain while setting slack, just to make sure you have the best average.

[bash3r]

Originally Posted by skierd

the terrain that you ride on, namely how often the swingarm goes above horizontal while riding at speed, determines the wear on your chain slider more than any other factor

CN: Its terrain, not tension, causing the chain slider wear imo. If you ride hard off-road or even just ride a lot of bad roads for a few thousand miles, budget $50 for the chain slider every here and again and keep an eye on it.

+1 This has been my thought, there's a definite reason for that swingarm slider, aka. "guard seal", to be there and made of good ole' plastic. There seem to also be a variety of factors that can play in your personal wear rate... weight of rider/gear(like Chadx mentioned), terrain, chain tight/loose, 12T or 13T, rear suspension setup. But ultimately it's just part of the gig, just like new tires.

It's up to us to keep an eye on it, and not be surprised if it happens, swingarm guard seal needs replacing or some jb weld on the swingarm, or worse case, the swingarm needs replacing.. just keep an eye on it for sure!

[kawagumby]

Originally Posted by bash3r

or some jb weld on the swingarm, or worse case, the swingarm needs replacing.. just keep an eye on it for sure!

Don't forget the swingarm can be welded easily and inexpensively.

[duanew1]

I have an idea for you jäger. If you are riding mostly street, you can jack your rear preload up so that it does not compress your suspension an expose that part of the swingarm to the chain. It will be a rough ride but it should help.

[duanew1]

I put a new chain slider on my bike a little while before a recent dual sport ride. I did not adjust my chain (mistake) and it was halfway worn through after about 400 miles. I am an example that a too tight chain can eat through the chain slider.

[Machtig]

I just replaced mine just over 1000 miles ago. I start the TAT and the darn thing is already toast. I don't know what to do at this point. I don't think its too tight? I don't think its too loose. I might be able to make it home but I'm gonna need a new one at any rate.

[kawagumby]

I just measured the center-of-countershaft to center of swingarm distance on all 4 of my off-road bikes and this bike is setup the same as the others. Assuming the swingarm buffer is made of similar plastic as the others (very likely) if there is excessive wear it is likely due to too tight chain adjustment and/or too small sprocket (if changed). I always run my chains on the loose side and never have any swingarm buffer problems, which includes my WRR.