Newb

Just joined the Forum and I have never really worked on one of these great vintage bikes. My apologies if my question has already been beaten lije a deceased Equine. I recently purchased a basket case 79 special. Ive addressed all the electrical issues, new carbs, cables etc. My issue is rhe clutch. The worm gear seems to be operating fine but the clutch wont work properly. Should I be able to press the rod in by hand because it doesnt seem to be moving at all. I can pull the small rod out and fished a ball bearing out with a magnet and those look just fine. Just wondering if this is possibly an easy fix or if I will have to severely tax my limited mechanical skills.

Welcome to the forum. Look inside the worm gear and make sure there is a ball bearing in there. As the clutch rod enters the worm gear it should ride on a ball bearing.......No ball bearing equals no clutch action....

tim

timbeck said:

Welcome to the forum. Look inside the worm gear and make sure there is a ball bearing in there. As the clutch rod enters the worm gear it should ride on a ball bearing.......No ball bearing equals no clutch action....

tim

Click to expand...

Thank you very much. Going to head out to my shop of horrors and check.

Well the ball bearing is there. I did order a new worm gear assembly from Mikes because it does seem a bit worn and the adjusting rod philips head is pretty worn out.

Hi CM:
There are actually TWO ball bearings you need to check on (see the schematics below - and note Parts #18):

• one ball is located inside the clutch "worm" (it is actually a power screw not a worm gear - although everyone calls it a "worm");
• another is located at the other end of the clutch actuator rod - waaaayyy at the far right hand end of the assembly where the clutch basket and plates are located (i.e. inside the RH side engine case cover);
• ....and depending on the year of your engine, some bikes will have a two-piece actuator rod and there must be a ball bearing between the two pieces (fortunately all three balls are the same).

You did say the your bike is a '79 XS650SF (the "F" indicates a 1979 model and the second "S" in the designation indicates a Special variant) and so it should have a two-piece rod with a ball between the two sections - but many people have swapped a single-piece rod for the stock two-piece unit (note the two-piecer in the 1978 and '79 schematics below) and again, note the two balls - Part #18 in the schematics. Basically, all XS650s have the same clutch with only minor variations after 1973 - so there could be lots of mixing and matching here and there.

Anyhow, my guess is that you while the "worm" in your bike has its ball () you may be missing one of the other ball(s) (one, two or both) - or - there is some other assembly error in the clutch. There a fair number of washers, spacers and a neat little roller-thrust bearing etc. in there and it is easy to put the whole ball-o-wax back together incorrectly and that will result in NO clutch function. Below are some schematics for a 1978 and 1979 clutch - I'd print these out and have them handy when you disassemble your clutch to check things over.

By the way - getting at the clutch is NOT a big deal - although you will need a large socket (which may be one of a 28mm, 29mm or a 30mm - and nobody knows why there are different ones used, but I have three bikes and there are at least two different sizes among them).

Anyhow - none of this is fatal and there are lots of folks on this forum who can help to get you going. Just ask lots of questions, post lots of photos and you'll get there!

Cheers and welcome from Canada's sunny southern coast in Windsor, Ontario!

Pete

Thank you friend. Amazing responses already. I think this forum is going to be a great resource.

You are most welcome, but the credit should go to the members who compiled those figure: Skull and 5Twins.
Anyhow - stick at it!

As the banks and politicians like to say these days...we’re all in this together!

Since this was a basket case, if you or the P.O. had the clutch apart, you or them may have assembled it incorrectly. In particular, the last step, installing the pressure plate. There's an alignment dot stamped on the end of one of the teeth on the inner basket .....



There's a small hole in the pressure plate and that dot must show through it .....



Get this wrong and the clutch won't work properly, maybe not work at all.

And no, you won't be able to press the clutch pushrod in by hand, the clutch springs are too strong.

Well worth a read..........from the "Tech menu" under "Clutch"
http://www.xs650.com/threads/xs650-clutch.143/

Well next up in the saga of the newb and his $800 basket case. I replaced the worm gear push rod assembly with a new kit from Mikes XS. The clutch feels great now. Feeling pretty happy about that I decided to fire her up and test out the clutch. Went to kick start her and it felt weird as hell. As if the kickstarter wasnt engaging. Felt like a bike with no compression which is not the case. I tested it after I bought the bike and it was excellent. Serioysly ready to light this thinv on fire and push it off a cliff.

Hey--- Sounds like you need to loosen the clutch cable at the perch and also loosen the worm gear. The worm gear philips screw only goes in lightly . Read the tech section for total clutch adjustment......

tim

Update. Obviously some sort of adjustment issue. I had the cable screwed all the way in at the perch (new cable) I screwed in the adjustment screw on the push rod gear til it stopped, backed off a quarter turn and tightened the lock nut. No luck. Clutched still engaged. Backed adjustor all the way out. Still engaged. Took cover off. No problem. Clutch not engaged, kickstarter feels normal now. Its as if the rod is too long.

Some pics of what's goin' on would be helpful.

cable could be to short...new worm gear not clocked correct.....

tim

Too embarassed to admit what was wrong but I got it. Thanks guys
-Newb

Okay I owe you guys a laugh since you were so helpful. Rod was in backwards and wasnt seating in the hole in the worm gear. Derp! Looks like I am going to be changing out the oil seal next. That rod is pretty floppy in there. (Thats what she said). That should be fun.

Good investigating.....
tim

Welcome. That bike doesn't look like a basket case at all You may want to address the lack of a front fender.

Don’t be embarrassed to share your mistakes. Many of us have been there! Sharing your results could ultimately help someone else who has done the same thing or possibly prevent from repeating your mistake.

The bike was a basket case qhen I got it. I've put a lot of work in on it. New Mikuni carbs, swingarm bushings, exhaust, paint, bars, lights,cables, etc. Front fender is on the list next along with tires. (They look new but the code says they are 20 years old.