Clutch slip on 840 engine, maybe wrong oil??

[blim840]

Hi guys been a while... I have recently fitted barnett plates and springs and the longer actuator (OMG its sooo much lighter) I have also used car oil not bike oil, this might be where I went wrong... thing is I am pretty sure the guy in the car shop said it was API SL so should be fine? after some research I have failed to find out online the specs for the oil I have bought, it is Lexicon 20w50 mineral, says suitable for petrol or diesel and high millage or older engines which would suggest its of an older spec....

I was running lucas plates and EBC springs, the lucas plates were a thinner friction area and I think this was causing my clutch to be quite grabb'y and harsh, also to avoid slip had to put washers behind the springs, the new barnett springs are longer by about the washers length so left the washers out, also bought some wiseco springs and they were the same length as the barnett but when tested using digi scales in my piller drill the barnett ones seemed to be putting more pressure down... the barnett plates seem much better and have loads more feel, likewise the longer actuator and replaced the pin as had worn w shaped, I have also fitted the plastic blocks in the cush drive as had destroyed the springs....

It still slips if I really nail it especially in 4th, so.. I am running SP370 pistons (840) XS1/2 camshaft (swapped the sprockets over) standard yamaha electronic ignition and 34mm Amal Mk2's so its moderately tuned but its not re-phased or race cam or anything, I'm running a 7 plate set up out of a 77 D model, I will re check the push rod adjustment when it has cooled down as I have only just got home... I know a lot of you go to 8 or 9 plates is this the only way?????

 

[Signal]

The car oil is probably not helping. The additives in car oils can cause clutch problems.
Perhaps try changing the oil first, as it’s the easiest to do. If the oil is the problem hopefully your clutch plates are not contaminated beyond redemption.
There are a lot of opinions on what oil is best do a search on this forum. More knowledgeable members than I will no doubt contribute to this thread.
I have been told Amal mk2’s really perform well on XS’s, what is your opinion?

 

[blim840]

Yes I was maybe thinking that, though I started using the oil before the new clutch and the old clutch didn't seem to make much difference it slipped with the bike oil as well.... I think I shall go to where I got it and double check the spec, I am under the impression the old spec SL doesn't have the additives so shouldn't be a problem, be interesting to know for sure coz motorcycle specific products are always more expensive, though I am fully aware that had I bought fully synthetic higher grade car oil that would def cause me clutch slip issues and not be suitable.... And yes Amal Mk2's are good, though my set are very old and a bit worn out, not sure if new ones are available that big as yet, I rang Amal and they said they were moving production and sorting out a new factory as the last lot from spain were so bad they sent hem back.... my set are original made in England, all the parts are available and I would replace all needle jets etc. as they wear, base settings are online and a good starting point, my set came off a 650 XS1 did have 250 mains, base setting is 260, on the 840 I am running 270 mains, not had it on the dyno but its not far off.... Mikuni's are supposed to be really good but I had the Amals as got them with a load of other bits off a mate so thought I'd give them a go, that and my bike was stolen and set on fire and I couldn't bring myself to buy new dyaphrams and floats for the crappy CV carbs.... Thinking of getting a dual throttle twist grip to do away with the crappy spliter as well to keep them better in sync!

 

[blim840]

I might add I only started using the car oil because it had got to the point I was topping the oil up every other fuel fill up, long story, blown big end, scuffed bore, overheated, I have since done a cheap and dirty rebuild as I had a spare crank, got new rings and honed the barrels to death to get rid of the damage the big end did, 1st over SP370 pistons are NOT available... and new stem seals, big oil pump and an oil cooler and so far so good its not using oil, put the big breather box on as well, had a copper head gasket and made a base gasket, third times a charm and all that, I have learn a hell of a lot though.... now its not using so much I could go back to using the bike oil... the quest to build a better XS...

 

[TwoManyXS1Bs]

To get a better understanding of the car oil versus motorcycle oil issue, do a forum search on "jaso".
Some 40-odd threads there that get pretty deep...

 

[Signal]

Thanks for the carb info.

 

[blim840]

cheers guys I will do more reading, as far as contaminating my clutch plates goes I don't thinks its a disaster as it only slips if you really nail it so pretty sure its not got loads of additives, though "jaso" sounds interesting as that would be motorcycle specific and could make difference, I will try changing it for motorcycle oil and I will post my findings... also it does feel pretty strong on pull away, I have ridden stuff with the wrong oil in and clutch slip can be really bad... I do object to paying a premium for motorcycle specific products if its pointless, for example my friend recently replaced the temp switch on his honda, the correct one was really expensive but he got a car one that was almost identical for a fraction of the cost, same heat range etc. and my rear mudguard was £15 from the trailer place and one from my local bike dealers is £60 and isn't as nice looking...... oh and I used water pipe fittings for my oil cooler because the place that sold me the cooler and lines didn't have anything suitable (and they do proper kits for some bikes) and I got some viton double lipped cam end seals from my local bearing dealer, they weren't cheaper but they should be an upgrade......

 

[blim840]

oh yeah I should say I replaced the steels as well, just the cheap pattern ones coz OE. are really expensive, the pattern ones look fine shape wise and fit nicely, turned up straight (always a good start) and were 1.4mm I think (I checked at the time and they were correct) I notice someone saying about thinner friction plates to get more in, would this be FJ1200 plates by any chance? I know some machining is required as well!

 

[angus67]

You can use, and most of us do, use diesel oil. it doesn't have additives, the bottle dosnt say jaso cert or not, but its used on a lot of bikes. I use Rottela T 15-40 in my xs's, and in my water cooled 2003 Suzuki marauder. 5 quarts for I think $20. Ive heard delo 400 is another choice, but I haven't tried it. diesels have really high compression, So Im sure that diesel oil is overqualified for our little motors.
When You drain your oil, zip tie your clutch lever back so the oil drains out of you clutch better, and let it drain over night.
Guys, please don't turn this thread into a oil debate, this is my experience, my .02, just giving a direct answer.

 

[jay760]

I use Morris classic 20/50 this is designed for older engines using guaze filters, I race mine and have had no clutch slip at all using this, available on ebay or most autojumbles.
Also you should check the plain plates, I found this is the biggest cause of clutch slip, when you get slip the plain plates get very hot start to blue and distort when they are like this you can normally flex them in you hands.

 

[blim840]

Cool thanks guys that does help answer my question, asked the guy in the shop this morning and he did confirm that it was the basic mineral low spec with no additives and it does say diesel and petrol and for older engines so I am fairly confident it should be ok, good tip on holding the clutch open to drain the oil out I will remember that, have played with the adjustment and so far seems better but not had chance to ride it far enough to be sure, its prob just bedding in... also interesting on the plain plate though these are new as thought should replace the lot as was having many problems with the old clutch so didn't want to take an chances and although it has been slipping I have not been slipping it loads, always back off when it lets go, the barnett plates were expensive and likewise the steels cost as well so not wanting to fry the new parts straight away.... will look at the old ones though, that might have not been helping, I am starting to think the more plates mod might be the next step, it does go exceptionally well since fitting the XS1 cam and getting the Amals jetted right, I am very keen to get the primary drive set, this should reduce the torque on the clutch so should help as well as giving me more sprocket choice and more legs, it revs out in top so easy.....

 

[jay760]

I always had clutch slip before converting to an 8 plate clutch.

 

[501Spanky]

I have also used car oil not bike oil, this might be where I went wrong... thing is I am pretty sure the guy in the car shop said it was API SL so should be fine? after some research I have failed to find out online the specs for the oil I have bought, it is Lexicon 20w50 mineral, says suitable for petrol or diesel and high millage or older engines which would suggest its of an older spec....

Google is your friend when it comes to oil searches. Automotive oil is designed with friction modifiers that work well in engines. These same friction modifiers are not good in a wet clutch system such as in an XS650. The JASO certified Rotella T-5 15W-40 mentioned earlier is what I run in both of my bikes. Great oil, cheap and no clutch issues. Before going any further with diagnosing your clutch - drain and replace your oil. Auto oil in wet clutches is a very well documented issue...

"basic mineral low spec with no additives and it does say diesel and petrol and for older engines". The key words in that sentence are highlighted and underlined - the first one is wrong and the second one is very important.

I looked up the spec sheet on Lexicon Link
The top of page 2 lists two friction modifiers. Your guy at the shop knows a great deal less about oil than I do. Yes, I do engineering for a living and spend a lot of time specifying oil for various types of machinery... Take my advice or don't - it's your time and money.

Best of luck!

 

[blim840]

501Spanky, thank you for that, I read the same spec sheet but to be honest it made little sense to me so your advice is much appreciated, so is the oil I have bought terrible? do I need to clean the plate or would just changing it sort it?? To be honest I only went for the cheaper oil because it was burning it so bad, since putting the new rings and stuff its much better so it would have been worth putting the bike oil in it... my bad.... also it is interesting you all have different opinions on what to put in, I think I will stick with 20w50 but I will get bike not car this time, my local bike shops stock either Morris or Silkolene, I did play with the adjustment as well, my cable was a bit stretched so have soldered a new nipple on but that made it a little short so compensated it by slackening the push rod adjuster a tiny bit, perfect, the actuator seemed a bit tight on the last bit and also the return spring is not perfect so by compensating the cable it has just moved the actuator enough that its all working smoother and the return spring seems a little more positive, was really surprised, you can really feel a good bit of free play and it has plenty of lift and is going into gear really smoothly, will use the bike to go get my oil so I will report back, I am pretty happy that its adjusted correctly now so it is down to the oil!!!

 

[blim840]

I was thinking drain it with the clutch open like Angus suggested and drain the cooler too, if I go on the bike to get the oil it will be hot so should drain well.....

 

[blim840]

Spanky, thank you so much for taking the time to read that spec sheet, I found the same one and I don't really know enough to really make any sense of it, I thought it was more about the hazard side of it, the actual bottle has very little written on it as well... I am no expert on oil and have no idea what chemicals should or shouldn't be in it, I am aware though that I might have cocked up, hence this post......

 

[501Spanky]

Spanky, thank you so much for taking the time to read that spec sheet, I found the same one and I don't really know enough to really make any sense of it, I thought it was more about the hazard side of it, the actual bottle has very little written on it as well... I am no expert on oil and have no idea what chemicals should or shouldn't be in it, I am aware though that I might have cocked up, hence this post......

You just got some bad advice from the guy at the shop. Nothing wrong with the oil itself, it's just not meant to be used in a wet clutch motorcycle ;-)
Drain and replace all of the oil per Angus. A slip or two will clean the clutch plates of any residual and you should be good to go. Enjoy the ride!

 

[blim840]

Thanks guys, I have changed my oil and the clutch has not slipped since, feels quite different and pulls really strong in 4th did the zip tie round the clutch lever, I spun it with the kick start to fling it off as well, quite pleased didn't have to clean the plates off that's a right result, and its still not burning oil either so wont bankrupt me topping it up..... Motul mineral 20w50 motorcycle oil!! Lesson learn't.....

 

[501Spanky]

Thanks guys, I have changed my oil and the clutch has not slipped since, feels quite different and pulls really strong in 4th did the zip tie round the clutch lever, I spun it with the kick start to fling it off as well, quite pleased didn't have to clean the plates off that's a right result, and its still not burning oil either so wont bankrupt me topping it up..... Motul mineral 20w50 motorcycle oil!! Lesson learn't.....

Another success story - congratulations!

 

[blim840]

lol, cheers spanky, to be fair I did have doubts about the oil, nice that there are experts out there willing to take 5 min to look up that spec sheet, that I had already looked at and I really didn't understand any of it so much appreciated dude and you are right the guy in the shop should have known better coz we discussed the whole wet clutch bike thing when I bought the oil, I won't hold it against him he is a nice guy and always does me discount's and stuff...

it has now proved to me 100 per cent it is worth spending a bit more and getting the right stuff unless its a complete oil burning wreck....