View Full Version : Clutch Slipping?
I recently rebuilt the motor, again. First time was just a basic top end, 416 bore, Hot cams 1, ported head and HD clutch springs. It ran strong except for some pinging due to the timing advace key that was already installed.
It shifted awesome with the new springs, instant power to the ground (sand).
After about 4 hours of riding time the shifter shaft broke. So another rebuild was in the works.
Current set up:
Ross 10.8 416
No Base Gasket
Thinner Head Gasket
Hot Cams stage 2
Ported head
LTE Dual Exhaust System
No Air Box Lid
Stock Gearing (for now)
20" Hauler 8-Paddles
Took it out last week to break it in. Runs great but it's a very top end motor, lost alot of bottom end. Not sure if I like it yet.
Later in the day I noticed there seemed to some slippage while shifting under acceleration. I know the oil needs to be changed after the break-in so that may be it, using 20/50. Went through a tank of gas in about 3 hours of riding.
I'm taking out again Monday or Tuesday for some fine tuning and would like to know what to look for to correct the slippage issue. I've never had any clutch issues uintil now.
mikeboone
09-11-2005, 06:42 PM
You running pump gas with this setup? Actual comp ratio is prolly over 12:1 with much smaller squish you have now.
You will notice problems with some oils and viscositys. I tried Mobil 1 syth. in my old 440 and couldnt even hold it still with the clutch pulled in. Went back with Motul 3000 and problem solved. Some oils that say they are wet clutch compatible dont seem to be.
Yes, pump gas 92 octane. Do you realy think it's 12:1? I belive the piston and gaskets are from an xr400 so the numbers may be different for the 400ex. I measured the squish on the first rebuild using the piece of solder method and it was .065", seemed kinda high to me. The piston I have now is the same size and make but it is a different one. There was a bit of pinging but not nearly like with the advance key. I didn't have decking or shaving done either.
I'll pay more attention to the clutch when I go out tomorrow to see what it is actually doing.
mikeboone
09-11-2005, 09:13 PM
Originally posted by JOEX
Yes, pump gas 92 octane. Do you realy think it's 12:1? I belive the piston and gaskets are from an xr400 so the numbers may be different for the 400ex. I measured the squish on the first rebuild using the piece of solder method and it was .065", seemed kinda high to me. The piston I have now is the same size and make but it is a different one. There was a bit of pinging but not nearly like with the advance key. I didn't have decking or shaving done either.
I'll pay more attention to the clutch when I go out tomorrow to see what it is actually doing.
I had a Ross 10.8 416 and it wouldnt take less than 100 octane. Altitude an such prolly has a part in what your specific bike may need.
I am not real knowlegdeable on formula to check squish and find out exact comp ratio. There are general guidelines as far as PSI versus octane requirements. Maybe Wilkins or Gabe can provide more answers? Yours may not be 12:1 but may be close.
I'm currently running at sea level, the Oregon Dunes are cool:D
I thought the XR400 parts equaled lower numbers for the 400ex that's why I went with the no base gasket and thinner head gasket to get a closer to true advertised comp. ratio, but of course I could be wrong.
I also thought the 'ideal' squish was .040" :confused: I gots so much to learn:p
Changed the oil and messed around with the clutch adjustment some more today, it helped but it still doesn't grab like it did when I first put the HD springs in. I'll be getting a new cable too.
Now the motor is breaking up at the upper rpm's:mad:
400exrider707
09-12-2005, 09:59 PM
Is it possbile you just need a new clutch?? Look on the bright side your going to turn 6000 posts!!!:blah:
Originally posted by 400exrider707
Is it possbile you just need a new clutch?? Look on the bright side your going to turn 6000 posts!!!:blah:
Here it is!lol!:p
I really hope I don't need a new clutch:(
400exrider707
09-12-2005, 10:05 PM
well what else would it be??? Thats about all I can think of. Maybe you could get away with just fibers. They could be glazed over. Your probably just going to have to pull it apart and see. Check your metal plates and see if they have a blue discoloration to them, if they do then they are bad as well.:ermm:
I'm hoping it just the cable needs more adjusting or replaced. Never had a problem with this one until now.
If it does need replacing of course i'll need to get one of them high dollar 8 plate set ups:o :devil:
bwamos
09-13-2005, 09:08 AM
What kind of oil did you use for the break in bro. I know you said 20w50. but what brand and type?
You may have a normal automotive engine oil with polymers in it that will make your clutch slip?
Make sure to use a motorcycle oil that is safe for a wet clutch.
Just throwing out an alternative possibility, since the oil was not specified.
Originally posted by bwamos
What kind of oil did you use for the break in bro. I know you said 20w50. but what brand and type?
You may have a normal automotive engine oil with polymers in it that will make your clutch slip?
Make sure to use a motorcycle oil that is safe for a wet clutch.
Just throwing out an alternative possibility, since the oil was not specified.
I used Torco 4 Stroke ATV oil.
wilkin250r
09-21-2005, 05:25 PM
Originally posted by JOEX
I also thought the 'ideal' squish was .040" :confused: I gots so much to learn:p
Yes, ideal squish is right about 0.040"
I don't know much about helping you with your clutch issues. I've never had any problems, myself, so I don't know how to go about fixing them.
First and foremost, make sure your cable is adjusted properly, but that much you already knew.
What basket do you have? New clutch plates or old?
TCracin440ex
09-21-2005, 05:52 PM
i kno im not a know it all on the motor department by far...but i have replaced quite a few clutches and it sounds to me like you need a new clutch....i suggested the Barnette clutch kit to Tina...she wont too pleased with it...something like the clutch was too hard to pull....but maybe your luck could be different...barnette clutches is all i used to run in my old 250x....
I'm still using the stock basket and plates with new HD springs. It worked great the first time I took it apart this spring.
Something I recently realized is i'm runnig with no base gasket and used sealer instead. Now i'm thinking some of the sealer may have got into the little oil passage that goes along the top part of the side cover. Not sure if that will have an effect on the clutch though.
TCracin440ex
09-21-2005, 07:40 PM
i doubt that has anything to do with it because i used to used silcone to seal up the cases and didnt hurt my bike so....
QuadJunkies
09-21-2005, 11:59 PM
Im going back to what seemed to work best.. Stock basket(which BTW thanks Boone for the tip off on me replacing it, I bet that fixes my 1st and 2nd gear now! :p ) And was running Barnette springs, but stock plates
Joe, maybe you need a new clutch /basket too!
cals400ex
09-22-2005, 12:38 PM
if you get a new clutch, i would get the sparks. it comes with an extra steel and fiber plate. it also comes with heavy duty springs. i ran that setup and it was much nicer coming out of a corner. i also ran the stock basket. i am sure hinson is the best but mine never gave me issues. it is possible you do need a new clutch. i always ran mobil 1 full synthetic after break in without any problems. i ran a 11:1 ross piston with no base gasket and a thin cosmetic head gasket on 93 octane. i never had any problems.
Thanks for all the advice everyone:) It may be awhile before I get this worked out due to the work schedule and having a place to ride:ermm:
cals400ex
09-23-2005, 03:14 PM
you could look at the fibers and see if there is any pad left on them. if not, that is your problem...
cals400ex
09-23-2005, 03:15 PM
you could also look at the steels. if they are blue, that means there were overheated.
A lot of good tips posted in here. Before disassembly try a lighter weight oil. Run a 10w-30 or 10w-40 to see if it helps at all. On my 440 I was running 20w-50 and it seemed to slip a bit with paddels. Went down to the 10w-40 and seemed to help a bit.
Your motor seems to be a top end motor because of the cam switch. Going from a stage I to a stage II is a substantial difference.
If you're in need of a new clutch let me know. I've got a pretty much brand new setup ready to go.;)
Originally posted by ZSK
A lot of good tips posted in here. Before disassembly try a lighter weight oil. Run a 10w-30 or 10w-40 to see if it helps at all. On my 440 I was running 20w-50 and it seemed to slip a bit with paddels. Went down to the 10w-40 and seemed to help a bit.
Your motor seems to be a top end motor because of the cam switch. Going from a stage I to a stage II is a substantial difference.
If you're in need of a new clutch let me know. I've got a pretty much brand new setup ready to go.;)
Yeah, it's definately a top end motor, not sure if I like it that way though. I'll probably put the Stage I back in eventually.
I'll try a different wieght oil before checking the plates.
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