Ignition advaner Inquiry

My 1976C model has some runibility (new word) problems, mostly low sp eed/idle/enrichener problems. I have installed new VM34s from 650 Central along with new Dunstall fake replica Mufflers. The problem has always been to much high rpm when cold start useing the enricheners. Carbs came from 650 central, so imsure they are good. Im getting off track here. Tonight i took a look at the ignition mechanical advance unit. After removing the chrome cover i discoverd lots a grease/oil in this area as well as a lot of slop, in which i would describe as the bobweights pivot. Also when i move the weights to their open position the springs dont return the weights back. Please advise. Mitch

yes, the advance unit will shag out with 20 or 30 years of neglect! pamcopete has a great video of how it should look and work on his site (and this site somewhere). if yours is too flogged out, you might need a new one from mikes, you might also need to change some seals if your getting oil in there. Have a look in the tech section for a great how to on pulling the advance rod and mechanism, cleaning, lubing and re fitting. get what youve got going as well as you can first! goodluck

Posted via Mobile

Y-man is spot on. Advance springs will get loose and allow the weights to advance early. This can lead to creeping idle speed when warm. The mechanism can stick also. The action of the points dragging on the cam will help the advance return to idle. I have an antique outboard that uses timing advance as a speed control. The carb is not throttled and is wide open. Shows how much advance effects engine speed.

The enrichener is a small carburetor. The piston/slide has a rubber seal on the bottom to block the fuel flow. When the enrichener is opened it gives much extra air as well as fuel so it is like opening the throttle to a fast idle. My old Triumph T140E has enricheners that are more sophisticated and I use a cable to a handlebar lever to throttle the enrichener. I also jetted the enricheners so it starts first kick but does not 8 stroke. With the enricheners wide open both my Triumph and XS650 have a high idle speed so your carbs seen normal. I close the enricheners as soon as I can after starting. After cold start with the XS, I open the enricheners a few more times while warming to get a shot of rich mix in the intake.

Tom

yamaman said:

yes, the advance unit will shag out with 20 or 30 years of neglect! pamcopete has a great video of how it should look and work on his site (and this site somewhere). if yours is too flogged out, you might need a new one from mikes, you might also need to change some seals if your getting oil in there. Have a look in the tech section for a great how to on pulling the advance rod and mechanism, cleaning, lubing and re fitting. get what youve got going as well as you can first! goodluck

Posted via Mobile

Click to expand...

Yamaman, i checked out Mikes site for repair/replacment parts for my advancer. They sell a spring replacement kit which is most likely what i need. With the engine not running and you manualy open the advancer should the springs return the advancer to the slow position? Mine does not and the springs feel like they have little to no tension on them. Also the pivot points seem sloppy. I did not see a complete replacement unit on the Mikes site. Please advise. Thanks Mitch

Before getting new springs, you might try shortening your originals. Cut one coil off of one spring only to start. Sometimes that's enough to restore the "spring back". Sometimes cutting both springs is too much, making things too stiff, and won't allow the advance to advance. That's why you only do one to start. Do the other if it still won't return.

So yes, when you manually twist the advance rod, the springs should return it to the retarded position when you let go. You may also need to clean and lube the bushings in the cam that the advance rod turns in. They need to be serviced occasionally. Make sure this stuff is good first before you cut the springs. Maybe servicing the rod will fix the problem without having to cut the springs.

mitchp normally 5twins would also say to clean and lightly lube the posts the bobweights are on also.
Careful with the little e-clips they will fly away and hide coming off and it is easy to break them if you try to squeze them off the posts to retighten.

Yes, basically clean the whole unit up. I just re-did mine last week after about 5 years of service. In the interim, I had kept the pivot posts and springs lubed with an occasional shot of foaming chain lube. I had thought I may find my unit starting to wear or the springs getting weak but that wasn't the case. It was still functioning fine (snapping back smartly) and advancing within the specified range.

I would suggest you clean yours up as best you can with it still in place. Then check under the cover a few times over the next few weeks or month to see if it's getting all oily in there again. If it is, you have a bad seal in the back side of the housing. If not, maybe the P.O. just soaked the thing in oil and grease and that's what you discovered.

5twins said:

Yes, basically clean the whole unit up. I just re-did mine last week after about 5 years of service. In the interim, I had kept the pivot posts and springs lubed with an occasional shot of foaming chain lube. I had thought I may find my unit starting to wear or the springs getting weak but that wasn't the case. It was still functioning fine (snapping back smartly) and advancing within the specified range.

I would suggest you clean yours up as best you can with it still in place. Then check under the cover a few times over the next few weeks or month to see if it's getting all oily in there again. If it is, you have a bad seal in the back side of the housing. If not, maybe the P.O. just soaked the thing in oil and grease and that's what you discovered.

Click to expand...

Electrical contact cleaner or engine degreaser? Also while im here thanks for the tip on the power brake check valve, although i had to hit up two places as each had only one in stock. I did view pamecopetes short video on a properly operating advancer using a strobe light. Thanks Mitch

you got a pic? what you really need to do is pull it all apart, pull the advance rod out, clean with whateveq you have, air dry, lube with light grease and reassemble. the rod could be sticking, and the springs arent made to overpower that. dont get rid of the original springs, the ones mikes sell are crap.

Posted via Mobile

Yes, taking it all apart is the best way but you may not want to disturb those original e-clips unless you have spares on hand. One of mine broke right in half as I was removing it. I had spares luckily and have since determined the size and bought a giant bag full. If you get jammed up and need some, send me a PM and I'll drop some in an envelope and send them to you.

Not quite clear on how to remove the rod. My clymer manual shows this rod as a two piece assembly that is pinned together. Is it easy to remover and more importinly reinstalling it? My bobweights seem a bit sloppy on the pivot pins. Im going out to get some contact cleaner and will be on this project tonight. What is considered to be a light grease? Thanks Mitch

Any solvent will do for cleaning up the unit. I use kerosene. Any automotive grease you happen to have on hand is probably fine. My 1st choice in a "light" grease is Kendall Super Blue. To remove the advance rod, remove the M6 nut on the advance side, pull the little disc off that engages onto the weights, and pull the rod out from the points side. The little cam that opens and closes the points can remain mounted on the points end of the rod. Some things to take note of - there is a locating pin for the little disc on the advance rod. Pull it out before withdrawing the rod so it doesn't get lost. There are alignment marks for proper assembly on the little disc and the advance unit itself, indicated here by the yellow arrows .....



Make sure you align them when reinstalling the disc or your timing will be off by 180°. The green arrow is pointing to the slot on the disc for the locating pin in the advance rod. When you try to pull the little disc off, it will probably be a bit stuck on there. Screw the nut back on by a couple threads and tap it lightly with a hammer to start the rod on it's way out.

Once you get the rod out, you'll see the outer bushing on each end of the cam has grooves cut in the I.D. These are to hold grease and keep the rod lubed .....



Clean any old grease out (you probably won't find any) and fill the grooves with fresh stuff .....



The factory recommends a lube with moly in it. I use VW CV joint grease because it has a very high moly content.

Thank you for the pics and a very through yet simple walk thru this removal. Hope this cures my problem. If i do end up having to replace the springs and with Mikes springs being sub par, where to obtain a replacement set? Are they availble at the Yamaha shop? This site has been a big help in getting the most out of my XS. Mitch

If your springs are weak you can clip the loop of one and bend up the next turn as a loop. This should get good snap back on the rod. If it doesn't clip the other spring.
If that gets it a bit tight you can then stretch the spring a bit.
Just try one at a time. Often just one is all you need to clip.
Leo

My 78 doesn't have the alighnment mark's, just plain,so i would just have to reset my idle timing if i removed my rod??????

jo jo, are you saying the advancer doesn't have marks? You should see the one on the advancer it self, it might be stamped lightly and be a bit hard to see, especailly if it's a bit rusty.
If you can't see the mark on the disc the weights engage it could be that some one before you had it apart and put the disc on backwards.
You might want to check for that.
Pulling the rod to clean and lube things shouldn't change the timing but it is always a good idea to check it.
Leo

Thank's for the reply xsLeo, Yes ur right, .now if i take the disc out will that throw off my timing?

Taking it apart and reassembling it right should not effect the timing, but as I said, it's a good idea to check it after your done, just to be sure.
Leo

Thank's im taking it apart tomorrow!