Drivetrain "grab"

[Cincykz]

Hi all. I've recently acquired a 2010 NT with just shy of 50k miles on it. Well used but well maintained by the looks of it. I've only gotten a few rides in due to central NY winter, but one thing I have noticed is that when starting up, as you let out the clutch and the bike starts moving, the bike kind of grabs forward in pulses until the clutch is all the way out. RPM changes up and down with the pulses. This is normal starts, idle or just a hair above. The clutch doesn't seem to slip at any speed or load, the bike shifts fine. It's also fairly mild and not causing stalls, but apparent as 'not normal'.

Rear splines look great and have been serviced with moly paste since new. Clutch adjustment feels right at the lever, no shock going into gear, no slip when out, lever has free play.

The PO has used rotella T6, and it's still in the bike right now. I have heard on the ST forum that T6 is no longer desirable in wet clutch applications due to a formulation change. This is one possibility.

My other thought is maybe a bad u-joint?

Just curious if anyone has had anything similar, or any ideas. I still have a few months of snow here.

Thanks!

 

[seagrass]

First thing I would try is a different brand of engine oil as the clutch is running in the engine oil.

Cheap, quick and easy and if it resolves the problem then you know the cause.

Seagrass

 

[junglejim]

Ya, I agree with seagrass.
Might be a rusty spot on the clutch that will probably smooth out.

 

[DirtFlier]

I've been using Rotella (dino-juice) for eons and it's currently still in both of my bikes without any problems.

Does the clutch lever move freely back & forth?

 

[Yoda]

Does the Rotella T-6 have the ‘MA’ designation? All of Honda’s motorcycle oils specify that for use in wet clutch applications. I would change to GN4 or HP4S (full synthetic) and bet that will solve the clutch problem in time.

 

[karl]

I ruined a clutch on my NT by not keeping up with the lever free play. First thing I would check now...

 

[mikesim]

In checking the Rotella website, T6 still carries JASO MA/MA2 certification which is the gold standard for wet clutch applications. I would change the oil using Rotella T4 or T6 and then make sure the clutch freeplay is adjusted properly and ride it several hundred miles and see what happens. Unless the clutch friction was damaged by the prior owner, I'll bet it will be just fine.

Mike

 

[cliffh]

Do you know if the previous owner ever had the valves adjusted? Tight valve clearance can cause low rpm missing under load.

 

[rc_heli_nut]

I would disconnect the clutch cable at the RH side engine case, and at the handlebars, and verify it's not kinked and moves smoothly. These are typically Teflon coated cables, sometimes the Teflon can start peeling off the cable and cause drag.

If the kink or peeling Teflon is in the enclosed area of the cable, this could cause erratic clutch engagement. Sometimes, finding the source of a problem like this means ruling out whats NOT causing the problem, my thinking here is it only take a few minutes and zero $$ to confirm cable is OK.

On the flip side, it could very well turn out to be the oil, as others here have stated.

 

[ARKNT]

Your description sounds like possible warped clutch plates but that is almost unheard of on an NT.
As others have suggested I would check the cable for drag and freshen up the oil.
I used Rotella in my NT and in current Versys with no issues.

Arknt

 

[Cincykz]

All great ideas, thanks folks. The valves have had three adjustments, and never been too far out of spec. I do believe the bike sat for a couple of years, so plates rusted together is a possibility. There is 0 slip when lever is out. I will check the cable, as it seems pretty likely, and the culprit usually seems to be the simple things.

The PO was a serious rider, covering most of the bikes miles on a few pretty epic trips, so I can't imagine the clutch has been worn out too much with mostly highway miles.

One other thing I had forgotten as I haven't ridden with the snow, when you shift down into first, the shifter doesn't hit a hard wall, but instead is still a little jiggly like it would be between the other gears. Up into fifth totally firm with no more play up, but when in first the pedal can still be jiggled down a bit. Shifts totally fine, never misses or pops out of gear. Maybe an adjustment issue. (I'm assuming they don't all do this, I've never run into another bike that has.) I hadn't considered that these two symptoms could be related, but I suppose it's possible.

 

[Russ Foster]

All the above is good advice as usual. Another angle: the fuel injection system will " grab" more than a carb engine. I noticed this at first until i read this is part of the price you pay for this overall, better system. I back off more slowly and try to avoid sharp back off's. One gets use to it. Again, there may be other issues but you may consider this.

Russ Foster
Dallas

 

[DirtFlier]

I don't think the shifter being "jiggly" in one position versus tight another is a concern. Inside the transmission is a shift plate that looks like of star with rounded points. The valleys between the points are the gear positions including neutral, with a spring-loaded detent engaging the valleys. The star is bolted to the end of the shift drum that engages the shift forks.

A previous poster mention "teflon coated" cables but it's been my experience that the braided wire, inner portion of the Honda cable is tightly encased in a plastic/nylon sleeve of some sort and it does a wonderful job of reducing friction. I would still disconnect the clutch cable at the lever and down at the engine to check that the inner wire has free movement back & forth.

 

[rc_heli_nut]

All the above is good advice as usual. Another angle: the fuel injection system will " grab" more than a carb engine. I noticed this at first until i read this is part of the price you pay for this overall, better system. I back off more slowly and try to avoid sharp back off's. One gets use to it. Again, there may be other issues but you may consider this.

Russ Foster
Dallas

I noticed this with my NT, and I installed a CrampBuster on the throttle grip. The extra leverage helped a lot with easing in and out of the throttle, and made long trips less stressful. Grip covers can help with this too, I had good luck with the Grab-On covers.

 

[cliffh]

FWIW, I had to replace the clutch cable on mine at around 27,000 miles. I noticed the clutch starting to slip and found out that the cable was rusted up inside. I bought the bike used, and the PO had at some point lost the rubber seal at the clutch hand end....also had the opening facing up. I'm sure that allowed water to get inside the cable sleeve.

At any rate, if you do change the cable it is no big deal. I purchased a cable on EBAY and the end pulled off before I could even get it installed. I then bought an OEM cable for what I think was a reasonable price. Just remove the cable from the clutch end and tape the new cable to the old, using the old cable to pull the new cable up through all the right areas. No plastic needs to come off the bike.

 

[Hondafan]

If you take off the clutch cable, it would be a good idea to remove the clutch lever from the perch and grease the pivot bolt. The last 2 Honda cables I bought did not have a teflon sleeve on the cable.

 

[Phil Tarman]

I had a clutch cable fail in '12 when my first bike had about 40K miles. Several of the strands in the cable broke and worked their way out through the casing next to the clutch lever. The cut through the swedge at that end of the cable. I rode for about 1K miles by shifting without the clutch. I only used the clutch when I had to stop at a light. I don't remember seeing what the inside of the cable looked like. If they are teflon coated, which they very may well, be, the coating wouldn't be on the wire, but on the inside of the casing.

 

[DirtFlier]

Phil - the lever pivot is the most common place for a Honda clutch cable to break. At the engine end, it's a straight pull so no strain on the cable.

I've found that cleaning that pivot during the winter and regreasing it helps a lot. When the grease gets dry and sticky, the barrel end of the cable doesn't rotate so it forces the braided wire inner cable to bend each time you pull in the lever and it eventually breaks. Dryness at the pivot can also cause erratic clutch engagement.

 

[Hondafan]

Problems are often a result of the simple things which are easily overlooked.

 

[mikesim]

Phil - the lever pivot is the most common place for a Honda clutch cable to break. At the engine end, it's a straight pull so no strain on the cable.

I've found that cleaning that pivot during the winter and regreasing it helps a lot. When the grease gets dry and sticky, the barrel end of the cable doesn't rotate so it forces the braided wire inner cable to bend each time you pull in the lever and it eventually breaks. Dryness at the pivot can also cause erratic clutch engagement.

Yup, I use Lock Ease which is a dry graphite lube on the clutch pivot. It doesn't get gummy and stays put. I do this about monthly along with all the lock cylinders on the bike.

Mike