SuperMoto Junkie banner

1 - 12 of 12 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hi,

After many months of saving money, getting a license, practicing, etc., I finally purchased my first bike. It's not a supermoto sadly, but it's close - it's something like an Enduro, with two 18 inch wheels, with road/dirt tires.

I know you guys won't like it, since it's a Chinese Lifan 250cc, but that's the only thing I could find 2nd hand with the money I had.

Anyways, the bike now has around 900km's (550 miles) and is coming close to its first service interval. I just noticed today that no matter which gear I'm in (4th, 5th, 6th, etc.) if I pull on the throttle, my RPM's go up but the bike doesn't pick up much speed. Now I'm not sure if my clutch is going bad, or if the oil is not right for the bike.

I'm currently using Motul 5000 mineral oil, 20W50. The service manual calls for 15W40, but I don't think that makes much of a difference? Plus the climate I'm riding is pretty hot, so I think the higher viscosity should help the clutch, not make it slip? I went to a repair shop and they said the clutch was definitely dying, but I still can't understand how that's possible even before the first service. Is it because it's Chinese? Is it the oil? :(
 

·
Registered
Joined
·
118 Posts
Oil can definately kill a clutch. Oil can also affect how it performs, some oils will cause slip or some oil will cause a chatter. I would try the recommended oil and then act appropriately.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 ·
Alright, I'll try changing to 15W40 dino on Monday. Still it's kind of weird to get clutch slipping from using oil specifically made for motorcycles, that's why I'm worried that the clutch has premature wear. We shall see :hmmm:
 

·
Premium Member
Joined
·
6,598 Posts
you're running a thick oil that is motorcycle specific which is what you want in a hot climate, the clutch should not slip with that stuff in there unless there's something else going on. going to a 15w40 mineral oil is the worst thing you can do, as it will run thinner when hot which could make the clutch slip even more and it's formulated differently compared to a semi- or fully synthetic oil.
 

·
Registered
Joined
·
36 Posts
I would also stay with the 20-50. How is clutch play? adjust at the engine till you have just a little bit of wiggle in the actuating arm, then adjust at the perch. Check clutch engagement. their should only be about 1/8 of free play at the lever. No freeplay and your clutch might be pulling on itself.

Next if that is good is you can take sparkplug washers and put them under your clutch springs. This stiffens clutch pull and can help keep the pressure plate tight.

While your in there check for clutch basket wear and try and get a look at the plates. The steel ones shouldnt be blue or grooved. the fibers should have some meat on them. Dont be afraid of a clutch its very easy to do.

do some google searching and see how easy parts are. also check for cross referance. A lot of chinese bikes rip off from others bikes and parts may be compatable.

Lastly, youre riding and having fun and you worked for it. Dont let anyone take that from you.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #6 · (Edited)
Makes sense guys, I'll keep the 20W50 - interesting though, some posters at the Chinese motorcycle forums said that the Motul oil I used is some kind of standard JASO MA, while I need "JASO MA2" in order to stop the clutch slipping, and they advised I buy Motul 7100 20W50 which uses that standard, so I'm going to try that as well in the next few days.

@Misfittoy I think the clutch play is somewhere around the 1/8th mark that you mentioned, not too stiff and not too lose, the bike is basically 6 months old and not much used, so I guess most of the stuff are in good condition. A mechanic checked the adjustment cables and said they are okay and he wants to check the clutch itself. I'll get my friend to help out in opening the bike again on Tuesday or Wednesday and see the clutch basked and plates, and add the spark plug washers if possible. Who knows, if I'm lucky changing the oil to the other Chinese standard could be enough. Baah I'll do both things. At the moment I can't even pull wheelies and 125cc scooters are faster off the line :damn: But anyways I am having fun and love the learning process, who knows, one day I might even upgrade to something better...

P.S. If anyone is interested, here are some pics I took last week while changing half the electrical system on the bike as it was dead and I had no horn, no left turn indicators... Note the battery brand, and amazing welding :D It has a performance air filter though :p



 

·
Registered
Joined
·
1,386 Posts
that's a cool bike!


just dump the oil, and refill with 20/50 (any brand is fine!) but make sure it DOES NOT say "energy conserving" or "friction modifiers" on the jug !!

ride it gently, but enough to fully warm up the bike, (20 minutes) and dump that oil again. refill with that 20/50 one or two more times.

once a clutch pack is contaminated, it takes a few oil changes to get it all out of the system.

on the last oil change, change the filter too.

you can pull the clutch basket and lightly (by hand) scuff the clutch fibers too but i doubt it needs that.

good luck
 

·
Registered
Joined
·
36 Posts
Realistically any type of oil that DOES NOT have friction modifiers will work. Reason being these friction modifiers are really detergents that reduce friction. Not good in a friction clutch. the way you tell is the symbol on the back of the oil. It will be a circle with the weight of the oil in the middle. on the top it will have API service and the bottom should be blank. If it’s not blank it has a friction modifiers.


Im trying to attach a picture.
imagesoil.png







For the moment forget wheelies, you’re just going to end up abusing your clutch more. Focus on learning the fundamentals. Go check out what I talk about in the trail braking thread and practice that. Learn body position. If you get all that down you’ll be passing bike worth 5x what that bike it.
 

·
Registered
Joined
·
537 Posts
On the clutch adjustment, make absolutely certain that with your hand off the lever you can wiggle the clutch arm at the motor end. If there is no free play, you're smoking it. You can't adjust it by where it engages, etc. You have to have the free play set, actuation point from there is just what it's going to be.
 

·
Registered
Joined
·
487 Posts
sharp side out

In my experience. If your clutch is slipping then something is up mechanically. Oil can exaggerate or mask the problem but if it's slipping at all then something is off. Bad adjustment most likely. I like my clutch to engage really far away from the bar and so often adjust it badly the first few times. Loosen the cable right up and go rip it up and down the road. When I say adjust it badly, I mean so that it only just pulls close to the bar, just enough for you to slip it in gear. Now : Does it still slip under power?

If so and before you go and spend a small fortune on oil lie it down on it's side and take the clutch case off. Check your discs and plates for any obvious nasties. One thing to make sure of is the metal clutch discs. If you look closely you'll see that each has a sharp side and a non sharp side. Feel the edges of the discs with your fingers. These should all be facing in the same direction. 'Sharp side out' is the conventional way. If they're not all facing the same way you'll get slippage or drag.
 

·
Registered
Joined
·
1,492 Posts
I hope you find the cause of your slipping clutch. It does not sound like an oil issue, but anything is possible.
The differences between JASO MA and JASO MA2 are minor. The main differences are relating to being safe for catalytic converters. I doubt that is why your clutch is slipping.
Clutches are basic mechanical things. They can slip because you used the wrong oil (doesn't sound like it is the case) or the slipp because the clutch pack is not being compressed tightly enough by the pressure plate. The second reason can be from a mis-adjusted cable or because the clutch pack is not thick enough. The is a minimum thickness for a clutch pack. It can also slip for other reasons, but if you think about how it works you should be able to figure out why it is not working.
Here is a link that explains JASO MA and JASO MA2.
http://www.whitedogbikes.com/whited...torbike-oil-what-does-jaso-and-jaso-ma2-mean/
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #12 ·
Hey guys,

Thanks for helping me out with the info. Will definitely stick to JASO MA2 from now on, and I'm loving that I'm finally learning more about the inner mechanics of motorcycles. Can't wait to someday have a garage and tinker even more :D And buy a proper KTM or Japanese sumo!

Anyways, I have an update. Most probably what happened, is the previous owner (I'm the second owner, bought it about ~20 days ago for $800, bike was first purchased 7 months ago for $1900), used cheap auto oil on the bike and contaminated the clutch plates. A few hundred km's after, he probably started noticing the clutch slipping and changed the oil, but didn't change the oil filter so the clutch stayed on with the friction modifiers, with what was left on the plates and in the filter. The dude really liked racing the bike off the lights and really keeping up the RPM's high, as well as clutch wheeling, as that's the only one you can do on a 250cc. Anyways, that probably kicked the clutch even more of this cheap ass Chinese bike, so now after the mechanic opened the bike, all 6 plates were burned out, thinned, i.e. completely unusable, the oil filter was almost completely clogged, probably even had the old friction modified oil inside, so the clutch was also probably starving for oil for the whole time. Can't believe he never changed from the factory oil filter than the cheap motorcycle dealership put in.

Good thing the springs and the pressure plate are okay. I think a few more hundred km's/miles and even the pressure plate could have gotten damaged.

I'm supposed to pay $12-$15 per plate, plus $10 for the oil filter, 2.2L of motorcycle MA2 oil and the mechanic himself, all in all it'll cost a bit over $100 to fix the mess. Supposed to get the bike tomorrow, so can't wait for the next ~12 hours to pass :D
 
1 - 12 of 12 Posts
Top