The starter grumbles

Hi everyone, I have a 1981 XJ750 that has developed a grumble when trying to start. I removed the starter and had it tested at an electrical shop and passed perfectly. So obviously the starter clutch is shot. Has anyone been able to make this type of repair without tearing the motor apart? The Dealer says they wont work on my bike because its to old, any suggestions?

 

STARTER MOTOR CLUTCH REBUILD PARTS:

sms6) OEM and aftermarket parts to rebuild your STARTER MOTOR CLUTCH DRIVE. Yamaha used a "centrifugal clutch" type of drive system to engage and disengage the starter motor drive from the engine gear, and over time the springs, spring caps, and dowel pins that provide the engagement action can fail....which is terrible, as these are a real pain to replace, and almost always require dis-assembly of the upper and lower engine cases.

However, there are a few alternative methods that might (or might not) save you some incredible effort and allow you to "dodge a bullet" and repair your starter clutch system in an easier manner; but, the success of such methods really depends upon whether the clutch failure is due to mechanical wear or damage to the pins, caps, or springs (in which case, you MUST somehow get in there and replace those items), or, if the caps and pins are merely "seized" in the starter clutch hub due to accumulated varnish and sludge, etc.----and in such a situation, then you might be able to clean out the mess and restore the clutch to an operational condition.

Methods a) and b) below address the problem of "sludge-seized" component pieces. Method c) deals with the problem of damaged parts. Note that if any of the major components are damaged---the clutch hub, or any idle gears or sprockets---then the engine is going to have to come out and taken apart to allow access to such larger pieces.


a) Pull the starter motor, and shoot lots of solvent (seafoam, carb or brake cleaner, etc.) directly onto the Starter Clutch Assembly.

Then, drain all of your engine oil and refill with fresh oil. Run the engine while on the centerstand until it's warmed up, drain the oil again, and fill with fresh oil.

If the starter clutch was just sticking, this method may wash away enough of the accumulated gunk and set you on your way.


b) Next, it may be necessary to actually run a solvent in with the engine oil in an attempt to loosen any engine oil sludge that has accumulated over time, and locked the starter clutch pins. Of course, such solvent should be run in the engine with the bike on the centerstand, and not any under load!!! Then drain and flush this solvent-and-oil mixture, refill with fresh oil-only, run on the centerstand again, and then drain and refill with fresh oil-only again......now you can ride it again. You want to make DARNED SURE that you get all of the solvent-saturated oil out of the crankcase before you put the engine under load, and risk chewing up engine bearings, etc. with solvent-thinned oil!


ALSO, TAKE NOTE OF THIS EXPERIENCE FROM ANOTHER XJ-OWNER:

"If there is not enough grip between the plunger and the roller, it can skip, causing the grinding, clacking noises you hear. I have been told by a Yamaha mechanic with over 20 years experience that it is very possible for some synthetics to greatly increase the chances that this will occur......"

So this weekend I drained the synthetic out, put some cheap 20W50 in, and rode it for a little while. Then I drained the cheap oil out and put Castrol GTX 20W50 in and the starter does not malfunction anymore, not even once! I cant believe it! I guess these bikes were not made to run synthetic---I'm sticking with conventional oil from now on."


c) If none of the above solutions work, then it might be time to do the dirty deed. Some people claim to have successfully accomplished a "Hail Mary" replacement of the starter clutch pins, springs, and caps with the engine together, but more than likely the engine has to come out of the frame and being dis-assembled to access this area. If you read this thread:

http://www.xjbikes.com/Forums/viewtopic/t=1700.html

you'll get a good idea of what challenges you're up against.


By the way, if you do decide to split the engine open and perform open-heart surgery, you might as well replace the primary chain and guide while you're in there, as those are also "wear items" and will cause problems if and when they start failing!

 

Thank you for getting back to me so soon. It's funny you should mention the synthetic oil part as I just happen to switch over to synthetic and never had this problem before. I have a heavy duty mechanic on site at my work and he had suggested I use 5w50 full synthetic because he said there was no friction modifiers as I was complaining about a notchy transmission. I tried it and found the the tranny problems improved dramatically but my clutch was slipping. So I bought Full synthetic motorcycle oil and changed the oil again and now the starter grumbling has appeared.

 

Problem solved. I drained the oil and changed the filter and poured a 1/2 quart of conventional through to flush out the sump and refilled the crank case and it starts right up minus the grumbling chatter. I just cant believe that the oil could cause such a problem. Thank you for the tip.

 

I had the same issue for the same reason - an oil change is an easy fix!

 

hey, my starter is acting wired too, when i push the button to star the bike, the starter will roll over no problem, but then it stops rolling the engine over, but the starter motor keeps rolling, is it the same problem, a wore out stater motor clutch? if you can get back to me id really appreciate it.

 

is it not possible to just find one from a donor and put it in as a replacement?