A handy guide to not rebuilding your slipping starter clutch.

Is your starter clutch slipping?
Check these things before assuming that it needs rebuilt, and tearing into the engine.

This list includes a issue that I recently encountered, but had never considered as a possible culprit before.

1. Make sure that you are using oil with a JASO MA rating or better.Such oils are engineered to work with wet clutches in older motorcycles, and do not contain the friction modifiers that will cause the starter clutch rollers to slip.
Choosing the correct Oil for a wet-clutch Motorcycle
If you do have a friction-modified oil in the sump, drain it. Replace it with a cheap oil of the correct specification, and dose the oil with Seafoam (or similar) to clear out the remains of the too-slippery oil. You can also pull the starter motor and spray carb cleaner towards the front of the engine case to help clean the starter clutch of the too-slippery oil. Do an oil change again after the slipping stops.

2. Make sure that your battery and starter motor are in top-condition. The battery should not drop below 10 volts when trying to start the bike, and the starter motor brushes should be inspected and the motor cleaned (especially if the bike is new to you) with electric motor cleaner. A starter that does not spin fast enough will cause the starter clutch rollers to slip.

3. The new-to-me-issue that I mentioned earlier:
Make sure that the problem isn't your clutch plates sticking together. Even with the clutch lever pulled in it is possible for an older set of clutch plates to remain in contact with one-another, which causes the poor starter motor to have to try and spin the transmission along with the engine. The starter clutch will slip in this case. The immediate remedy is to roll the bike forward while pulling in the clutch lever. That will break the clutch plates free and allow the bike to be started without any problem. This issue will turn up even when the transmission is in neutral.

 

Thanks for this. I wondered about the starter clutch issue since I got this bike last fall. No issues so far.

 

Good write up, and an exhortation to use oil rate properly for wet clutch motorcycles!

 

Please start a thread about your problems. Better yet, add to any existing thread about your motorcycle.
I don't know what videos you watched, but there is no way to turn around the idler gear in a shaft-driven XJ without splitting the engine cases.

If your battery is draining during a ride you have a charging issue. Worn alternator brushes are the most common cause and easy to fix.

 

Thanks Kmoe, prob will start with new brushes,ck teeth etc.

 

Next, check the rectifier.

 

Thanks, HC ...did solenoid, will pu bat on load with meter. I should expect 13-14 v while running correct?
Its just annoying to get quick clean starts when cold outta garage....but after everything warms up....it decides to mis-behave.

 

Thanks for the write up!
I have that issue since i bought the bike, changed with oil for proper jaso, but still can't crank. Rebuilt the starter motor and it just spins the engine a little then slips and spins in the air... I will try the other fix you mentioned, the carb cleaner through the opening and the stuck plates maybe...
I really would love not to have to split the case. Can i upload a video on this forum?

Thanks

 

You can create a YouTube video and post the link on the forum, that will work.

 

Here it is :
So it cranks for a little bit and then spins...

 

I'd think that stuck clutch plates are the likely culprit. They are certanly easier to remedy than rebuilding the starter clutch.

 

Thanks k-moe, I've tried it all now. Brake cleaner in there, pulling the clutch lever, rolling the bike back and forth. The brake cleaner helped a bit. It stayed engaged better but still slipped eventually...

As I have pulled everything else in the bike I can't get it started and running warm to do another oil change. I'm gonna try still to do a cold oil drain (all night and pull new oil tomorrow) basic mineral jaso (cheap)

And try it again.

When the battery is fresh it slips out even easier.

 

In that case it's likely in need of a starter clutch rebuild. Keep in mind that it's apretty easy bike to bump-start, so you can put the teardown off for a long while if you want to.

 

Have same problem, especially after a short ride(engine oil is toasty) AND turn off bike. Try restarting 5 min later and she plays the boxorocs thing. So, I started (ahem) with the starter rebuild kit...heck whats 30 bucks. My starter is Now up to snuff...ck that box.
A FRESH STRONG battery turns it over right away...yesss! Yes I also bucked up and git me a new LiPo battery with 400 cold cr amps. ( Yes, came a month later, was $107, and the poles are swapped(annoying) but aint 10lbs ; ] !
To Kmoe's point, I do have to install new clutch friction pads, so I can eliminate that sticky possibility too. The last thing I will do is make sure nothing is draining my battery while she is sleeping, and the charging system is doing it's job while running.
Fresh strong battery...priceless.
81 xj750

 

My two cents , I have now did two starter clutch replacements , my findings one had a roller with a flat spot and both the springs were shorter than the new springs . My thought the old springs after 30 plus years of wear and tear , loose their tension hence so the rollers slip .The rebuild kit I used has a heavier spring and had new rollers and the new cups has an oil hole in the bottom ( the original is lacking the oil hole) . I learned the hard way when you split case DO NOT turn the crank over with the cam tensioner out ( you can skip cam timing) . After removing engine from the frame , I can split case in about an hour , I know Kmoe has done deed as well but these are just my findings . My original engine to the bike the starter clutch slipped when engine was hot , tried oil change , heavier weight oil , tried Seafoam in the oil , I replaced the clutch as well , rebuilt the starter, the carbs were taken to church as well . I bought another engine , this engine had 38k on it ,but had 150 psi on all four cylinders, I got two years out of last summer it started slipping and got to the point would slip even cold. This engine was spotless inside when I tore it down , the other engine has low compression with two cylinder at 90 psi ,one at 140 psi and one at 150 psi , I'm hoping I did not kiss a piston with the valve when I skipped timing . Lesson learned maybe in the spring I will do a leak down test to see if it is piston rings or the valve. Anyway this is my starter clutch experience.

 

This new LiPo battery, bangs that starter out and she turns over in one press of a button.
But, because its cold now and I can't ride, I cant test what happens after she is warmed up. (You know...ride 20 min, turn off for 5 min, then try to restart.....to see if the "b-o-r" (Box-o-rocks) noise comes back.
My guess is, over time that spring weakens.
I have seen some youtube vids where guys discuss removing the spring. Their reasoning is, the spring prohibits full gear tooth contact. Not sure if that is true.

 

The springs are what make the starter clutch work properly. The starter gears on an XJ are always in full contact with one another (which is why there is a starter clutch). I have no idea what bike those Youtube guys are refrencing, but it isn't an XJ.

 

When it starts slipping it us time to roll up your sleeves and split the case and replace the springs and rollers . A good set of torx bits ( the type you put on a ratchet) and another set of Allen sockets . See my thread on The dreaded starter clutch I have pictures .

 

Virago ...I think. Uses a bendix with clip and spring. The spring pushes the gear back, once the engine turns over.

 

Roger that. Kind of a bummer, bike only has 9800 miles.

 

Yes it does. This thread is about the XJ series, not the Virago.

 

Hi Everybody. I know I'm a little late to the party here but I'm just starting to gather research for my slipping starter clutch issue on my Seca 900. I bought it with 32k and it now has about 38k. The starter clutch was slipping when I initially bought it. . My issue is pretty similar to a lot of what I've read: it only slips on a warm start. Yes, I have tried all the usual tricks to find out if it's NOT the starter clutch. New battery, SeaFoam flush, thicker oil, rebuilt starter motor. I currently use the Shell Rotella Deisel oil. The only thing I haven't considered was the sticky clutch plate scenario presented by K-Moe. Would a slipping starter clutch on a warm start be a possible candidate for the sticky clutch plate problem? I can see that on a cold start but it seems to me that if the bike is properly warmed up that the clutch plates would not be sticking. Nevertheless, I REALLY don't want to crack open the engine so I will go and find out.

As I understand the test, when I try to start the bike and the starter clutch starts slipping I should roll the bike a few feet forward with the clutch lever pulled in and then try and start again. Does it matter if the bike is in Neutral or not when I roll the bike forward?

 

Hmmm, now, I wonder. Perhaps read the original post again...
Ok, read it. It doesn't say to put it in gear, but really, what would pushing it do if not in gear?
So if you're still unsure - put bike in gear, pull clutch and push to free the plates.
If you can't free the plates you have a clutch issue too.

 

Thanks Minimutly. Is there a way to verify that the clutch plates become unstuck after doing the procedure? Is it possible that even after rolling the bike forward that the plates would still be stuck?

 

You seriously need to stop typing and start thinking. Push bike in gear without pulling clutch in - does it roll?
No, of course not. Push on it, then pull the clutch it. It should roll. If it does you know the clutch is free.
There, saved you thinking too hard....
Sorry, being mean and sarcastic, but I meant the bit about thinking rather than typing.

 

Please do not talk that way to people on here. There's nothing wrong with the question I asked but there is everything wrong with belittling, bullying, and berating people for asking honest questions. We are all here to learn. That's the whole point of this forum. I think you should take your own advice: STOP TYPING AND START THINKING.

 

Okay my two cents ,since I had to do two of starter clutch , one engine only did it hot, the other started out that way eventually did it all the time. This was a spare engine I had been using , I split the case and found one roller was galled and the springs had lost tension . I bought a rebuild kit from the UK very good kit . the first engine I did I made mistake of moving the crank with cam tensioner out I have not looked but I may have bent a valve so that I will look at some other time. The spare engine I'm running now runs great and so far no starter clutch slip. I got lucky both engines chain guide were in good shape so did not have to pull head and the chain guide . Honestly it was not hard to pull found the engine , granted I'm a 35 years experience as a aircraft mechanic, I did the deed over 5 days mostly waiting on parts .

 

There was everything wrong with your question - it told me clearly that you weren't thinking.
Appologies if you took my answer to be anything other than constructive - I'm still hoping it was.
All the best.

 

To clear this up...the machine needs to be in neutral. If the plates are sticky they will break free. If it’s in gear you won’t be able to roll the bike nearly as easily, and the plates might still be stuck even after rolling the bike forward. If that is the case then the plates have corroded together and should be replaced.

 

You apologize AND insult in the same breath. You're wierd dude.

 

I tried the sticky clutch plate test 3 times and each time I tried it the bike was able to start fine without the starter clutch slipping. I guess it's time to do a clutch job and replace the plates. Should I replace both the friction AND clutch plates. I think I've seen situations where all you had to do was sand down the friction plates a bit and that fixed the issue.

 

" Replace it with a cheap oil of the correct specification, and dose the oil with Seafoam (or similar) to clear out the remains of the too-slippery oil. You can also pull the starter motor and spray carb cleaner towards the front of the engine case to help clean the starter clutch of the too-slippery oil. Do an oil change again after the slipping stops."

How much solvent in the oil is too much?

 

After 30 plus years of poor maintenance, infrequent oil changes , cranking way too much on the starter, low battery charge ...this takes a toll on the starter clutch , when I did the replacement, the springs loose their tension which means the rollers "skip" and slips . Using heavier oil will only get you by a short time , my started slipping only when hot , it finally got to the point it would not hit at all , after tearing into it one roller was galled as well. Since doing the deed no slipping .

 

I'm going to install new clutch plates this weekend on my Seca 900. Can I rest the bike on the kickstand to prevent oil coming out or do I have to completely drain all the oil?

 

I think you can just put it on the kick stand. Try it by looking through the oil level window on your clutch cover.

Soak your new plates in clean engine oil overnight.

 

Awesome. Thanks

 

Hey guys, I just wanted to share a positive experience that may help with everything from starter clutches to gummed up oil pumps in all kinds of engines, and I'm surprised that I never thought of it before!

My XJ1100 was struggling to turn over shortly after I bought it, initially I thought it was the starter motor so I tore that down and gave it a once over.

After realizing that it wasn't the problem, and having just rebuilt my XJ650, I knew exactly what I didn't want to do, which was some form of surgery.

So instead I just drained out the oil, poured about 5 litres of diesel into the crank case, (plugs were already out), and spent half a day turning it over with the starter motor every now and again, then letting it sit for a while in between.

Eventually I drained it all out while turning it over, ran some cheap/good oil through, drained and filled up with the good stuff.

Plugs back in etc and she fired up faster than ever and runs beautifully!!

I see other people here have tried similar things and I just wanted to add my 2 cents for anyone who's stuck on this.

 

Do you have new bolts with your clutch kit. If not you should fit new ones. Torque them to spec too. @Polock had a photo of a clutch which broke up, found it.

https://xjbikes.com/forums/threads/clutch-issues-after-rebuild.130158/#post-660933

 

Approximately how long would you turn it over each time with diesel in it? Does it have to be diesel? What did you do with the diesel afterwards?

 

check

 

From Cold start( of course a fully charged battery) mine starts every time.
The 'hot engine' restart after my stop to the bank or deli is the issue. Box of rox kicks in. But I also found that if I rolled the bike a few feet ,while pressing starter I got the clutch to catch.
I have new plates to install and change oil.
Re oil: since most synthetics are JASO certified, I thought the motorcycle specific Mobil and Valvoline products were ok 5w40@ $9ea. If not, what cheaper motorcycle brand oil are you putting in your Xj750? I am not sure I have seen any "non synthetic" motorcycle oil at autozone etc.

Thanks guys,

 

Short answer is Shell Rotella T4 15W-40

 

Shell Rotella T4 15W-40 runs about 15$ a gallon vs the 9$ a quart for oil with a motorcycle on the label
run some seafoam in the current oil it will clean the inside of motor and clutch plates then change the oil. I add seafoam just before my oil changes and run for 2 to 3 hundred miles then do my oil change

 

bought a gal. t4 today $22.99 at oriellys. napa sold out, guy said no delivery expected. homedepot empty too.
had to search for it. --coulda amazoned it.

 

Just replaced the friction plates to my Seca 900 hoping it would resolve the slipping starter clutch issue and it was a big fat FAIL.
Next up: Seafoam flush. I've tried the Seafoam engine flush once before but only ran the stuff in my engine for 10 miles before I did the oil change. I'm going to go for a hundred miles this time. I know everyone recommends SeaFoam but I've been looking at this LiquiMoly engine flush treatment made in Germany. Anybody have any other options they recommend besides SeaFoam?
The directions for SeaFoam recommends adding an ounce of Seafoam per quart of oil. Would it hurt to put a little more or is that just overkill?
Would it help to run the bike with the SeaFoam over the course of maybe 3 or 4 days so that it really cleans it out good or would just one day of riding be plenty?

 

Thanks guys for the Seafoam and Rotella spec. I will clean it out, change oil, filter. I have new clutch friction plates, springs and bolts, ready for install.

 

walmart sells it