clutch slipping under acceleration

To start. I changed oil with rotella T6. Plenty of fluid in clutch reservoir. Now Under hard acceleration it slips. I read in other posts about a clogged return hole??? Where do I find that? Or do I need to replace plates? I asked my mechanic about it Barretts??? he said to replace it, it would cost around 500-600 for parts and labor. I reallyu don't have that kind of cash and the wife and I are leaving on our long trip for Kentucky (mountains) in July. It only slips under HARD Accleration. i.e. Passing etc... Should I be concerned?

Stat

Most of the time a clogged return port will result in slippage all the time. It's the small port in the bottom of the Master cylinder reservoir that is farthest from the lever. You should be able to see fluid come back out of that hole when you release the clutch with the MC cover off but be ready to pull off some Matrix like moves to avoid getting shot in the eye with brake fluid so release it slowly.

My first suggestion would be to go back to whatever oil you were using before changing to the T-6 and see if it still slips. I personally prefer T-4 15w-40 or Castrol GTX 20w-50. The clutch uses a diaphragm spring instead of multiple coil springs and the diaphragm can crack also causing slippage.

The Barnett pressure plate is an option for about 130 bucks plus about 10 bucks for a side cover gasket if you are a DIY kinda guy. I did mine myself but you definitely need a torque wrench to do it right. Here is a link to where I got mine on Amazon. https://www.amazon.com/gp/product/B000GRXT50/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Slipping definitely will not get any better, only worse. It could be the oil, but I doubt it. Not a big deal though. Take a read on how to replace the clutch in the tech section and I think you will find it can easily be done. You don't even have to drain the oil. Just some basic tools and a torque wrench. Heck, you could go out and buy all the needed tools and do the work yourself and be a whole lot cheaper than the dealer. Just remember,,, lefty loosey, righty tighty.

Also make sure your Master Cylinder fluid level is not to full, there needs to be an air gap between the fluid and the cap..

Have you ever replaced your clutch plates? If not, it is probably time.

My clutch started slipping...in 4th and 5th gears and I went with Skydoc's clutch kit. As Carl mentioned it is something you can do yourself with minimal tools. There might be someone in your area that can assist you if necessary, and of course lots of support online and Earl is good about replying to questions as well.

https://www.venturerider.org/forum/showthread.php?139137-Second-Gen-Heavy-Duty-Clutch-Spring-amp-Full-Disc-Upgrade-Kit!

Before going for the juggler what Puc said is true. If your sight glass is still clear?? the fluid level should be in the middle of the glass. The expansion hole is located at the bottom of the reserve. The one that looks like someone started to drill and then quit. There's a very tiny hole in the bottom of that hole, and the wire from one of those twist ties you find in the produce section of the grocery store will work to clear it... The hole sometimes gets clogged and won't let expanded fluid back into the reserve... the reason for not filling the reserve to the top. Also a sign that the clutch needs to be bled.. I'm not sure, but if the T6 has friction modifiers that will also cause the clutch to slip. If this doesn't stop the slipping?? go for the Juggler.... :-)

If you get a new spring or a Barnett pressure plate, you could swing over to Orlin's maintenance day and get all the help you could ever want. It is on the calendar for the last weekend in June.

To start. I changed oil with rotella T6. Plenty of fluid in clutch reservoir. Now Under hard acceleration it slips. I read in other posts about a clogged return hole??? Where do I find that? Or do I need to replace plates? I asked my mechanic about it Barretts??? he said to replace it, it would cost around 500-600 for parts and labor. I reallyu don't have that kind of cash and the wife and I are leaving on our long trip for Kentucky (mountains) in July. It only slips under HARD Accleration. i.e. Passing etc... Should I be concerned?

 

Stat

I had a similar problem with my clutch slipping on acceleration and I changed over to Rotella 15/40 and it stopped slipping. I recently switched over to synthetic Quicksilver motorcycle oil which is 20/50 and I really like that. That being said if it is your clutch and you want to change it here is a youtube video that may be helpful.

If you can get over to Fond du Lac with parts next weekend (6/22-23) we can tackle the clutch. I've done several. Most likely just a weak spring. We can mic the clutch parts to make sure.

Streets and Trips says it is 2 hours each way.

I've put a Barnett kit on mine and couldn't be happier. I did a write up on here somewhere.

Let me know.

RR

Thanks for all the input guys.... I'm going to try the Rotella T4 15-40 oil first instead of the synthetic T6 15-40 to see if that changes the slipping. If not. then I'll consinder the clutch replacement.

Stat

Neither Rotella T4 or T6 contain friction modifiers. I have used T6 in my RSV's for over 100,000 miles with no adverse affects. Check the Member Vendor section of the classifieds for Skydoc17's clutch spring replacement kit. It is low cost, very effective, contains everything you will need and is a simple job. Earl will provide tech support if required. You'll find the hardest part is removing the old gasket.

A weak clutch spring is a very common thing on these bikes. It first manifests as a slip at full throttle in 4th or 5th gears. The fix is to get the stronger spring from @skydoc_17 or spend the big bucks on the Barnett system. they both work and will last a lot longer that the original spring did.

To do the change will take about an hour the first time you do one, about a half hour if you have done it once before, and about 3 hours if you invite a friend or 3 that has done it before ......... it may also cost a couple of Pizzas.

$500-$600 to change a clutch spring is highway robbery.

Unless you have been slipping this for a LONG time or you really ride your clutch a lot, the plates are usually still fine. You will need a good calipers or a micrometer to tell once you have them out. A new clutch plate is 3mm (.1181 inch) thick and the wear limit is 2.6mm (.1024 inch) thick. New and worn out look pretty much the same to the naked eye.

Even if you have NO tools at all, you can buy the parts and the tools to do the job for less than the $600 the stealer wants, and it is NOT a difficult job for even an inexperienced person to do.

Hey Darren,

First off, thank you everyone for the kind words about my Clutch Kits, as always, it is greatly appreciated. Now, about that clutch! Darren, you didn't mention how many miles you have on your current clutch. I personally would not take my motorcycle AND my wife on a multi-hundred mile road trip with an "iffy" clutch, but that's just me. Even if you manage to "limp" thru the entire trip, and make it back home, your riding enjoyment is going to be diminished to the point where it might have been more fun to take a Greyhound Bus instead of your Venture. I would save the money of a second oil change and put that money into either the Barnett kit or one of my kits. The oil that you have put into your scoot is not causing this issue, the weak Clutch Diaphragm spring is. I absolutely guarantee you that I can have clutch parts to your home by mid week and will personally walk you thru the clutch replacement over the phone. This project can be done on the side stand and you won't have to do an oil change when you are done. This will be the best two hours you will spend working on your motorcycle.

Now for the back story. From the late 70's to the early 80's Yamaha used the 6 compression spring clutch system on all of the inline fours and the MKI Ventures from 1983 to 1985. In 1986 they went to the single Clutch Diaphragm Spring, which at the time was quite the performance upgrade. By removing the unsprung weight of the larger pressure plate and the 6 compression springs off of the end of the crankshaft buys you several extra horsepower to the rear wheel. This next bit is my own personal opinion. The Barnett Clutch Kit is an excellent product, it solves the issue of the slipping clutch, and lasts a long time. The only issue I have with the Barnett Clutch is installing older technology on a 21st century motorcycle. The Barnett Clutch is a direct copy of the 6 compression spring clutch Yamaha used on their motorcycles 35 years ago, and they charge 3 times the price for that unit. By installing a stronger HD Clutch Diaphragm Spring in your Clutch you will solve the slipping clutch issue, and you won't lose any horsepower in the process. Like I said, just my personal opinion.

Even if you purchase the Barnett kit, I would be happy to walk you thru the install because I want you to have a wonderful time on your trip, and not sweat your slipping clutch wondering if you are going to make it home or not.

If I can help you with parts, or a link to the install of either kit, just let me know.

Earl

Hi Earl

So as not to Highjack this thread I have sent you a PM with some clutch questions for my future Project.

Thanks in advance

HermanK84VR

I can attest to Skydoc's spring as I have it in two bikes. I have over 20k miles on my 07 clutch spring and just returned from a 2176 mile trip, two up and pulling a trailer. Worked flawlessly.

Hey Darren,

First off, thank you everyone for the kind words about my Clutch Kits, as always, it is greatly appreciated. Now, about that clutch! Darren, you didn't mention how many miles you have on your current clutch. I personally would not take my motorcycle AND my wife on a multi-hundred mile road trip with an "iffy" clutch, but that's just me. Even if you manage to "limp" thru the entire trip, and make it back home, your riding enjoyment is going to be diminished to the point where it might have been more fun to take a Greyhound Bus instead of your Venture. I would save the money of a second oil change and put that money into either the Barnett kit or one of my kits. The oil that you have put into your scoot is not causing this issue, the weak Clutch Diaphragm spring is. I absolutely guarantee you that I can have clutch parts to your home by mid week and will personally walk you thru the clutch replacement over the phone. This project can be done on the side stand and you won't have to do an oil change when you are done. This will be the best two hours you will spend working on your motorcycle.

Now for the back story. From the late 70's to the early 80's Yamaha used the 6 compression spring clutch system on all of the inline fours and the MKI Ventures from 1983 to 1985. In 1986 they went to the single Clutch Diaphragm Spring, which at the time was quite the performance upgrade. By removing the unsprung weight of the larger pressure plate and the 6 compression springs off of the end of the crankshaft buys you several extra horsepower to the rear wheel. This next bit is my own personal opinion. The Barnett Clutch Kit is an excellent product, it solves the issue of the slipping clutch, and lasts a long time. The only issue I have with the Barnett Clutch is installing older technology on a 21st century motorcycle. The Barnett Clutch is a direct copy of the 6 compression spring clutch Yamaha used on their motorcycles 35 years ago, and they charge 3 times the price for that unit. By installing a stronger HD Clutch Diaphragm Spring in your Clutch you will solve the slipping clutch issue, and you won't lose any horsepower in the process. Like I said, just my personal opinion.

Even if you purchase the Barnett kit, I would be happy to walk you thru the install because I want you to have a wonderful time on your trip, and not sweat your slipping clutch wondering if you are going to make it home or not.

If I can help you with parts, or a link to the install of either kit, just let me know.

Earl

thanks for the reply I have just over 40k miles on the 08 RSV, funny tonight driving to work (I'm at work now) it didn't slip, if it did it wasn't noticeable, I was in 3rd gear when I hammered down. I'll test again in the morning on the way home. thanks

I will also attest to SKYDOC's fix using the heavier spring. The clutch on my 07 started to slip around 40K, put one of Earl's springs in and no more slippage. I pull a trailer on occasion and used synthetic oil, at nearly 80K when I sold it no slippage, I did not change out the inner most friction plate (half thickness one) with the full thickness one Earl includes in his kit, so it told me the spring was the issue. As Flying Fool stated, easy job to do, if the bike is on the side stand, you do not even have to drain the oil. Worst part of the whole job is removing the old gasket. Do be sure to use a properly sized inch pound torque wrench set to the proper value when installing the bolts, several on this and other Yamaha forums have managed to snap off the heads using the wrong setting.

Good luck, keep us posted.

Hey Darren,

With 40K on your stock clutch, you have done better than many! This lets me know that you have a good riding style as far as your clutch usage is concerned. Good for you. The reason you didn't get any clutch slippage (in my opinion) is because you were riding at night, where the temps are in the low to mid 60's at most, and you were riding one up. If it was daytime, 2 up, fully loaded with temps in the 80's or even higher, I think you would see more slippage. I am off to PT now, but when I return I will send you a PM with a link for the install and other options.

Thanks Darren for letting me help you with this project!

Earl

It only slips under HARD Accleration. i.e. Passing etc... Should I be concerned?

 

Stat

I replaced my clutchspring due to slippage when my bike had 5952 miles on it. MUCH BETTER!. I reinstalled the half plate later because I wanted my old clutch lever feel back but with still no slippage. Click below for writeup that includes some pics.

https://www.venturerider.org/forum/showthread.php?99519-Clutch-Upgrade-using-Skydoc_17-Kit