Question about 1981 Yamaha XS 650 H
I have a 1983 920 ViragMK. I see on some sites there are TSB's for the starter shimming. However, my eyes are not able to focus on print that is .003 high. Can anyone tell me where I maight find this information on line that is readable?
I also seem to have inherited a ******** mechanics bike. THe carb boots are siliconed to the intake, and the front one is on the back cylinder, and vice versa. Can the vacume lines be rerouted to make a mess like that work, or is it more trouble than it's worth?
The TSB on the starter motor shimming is really very basic. You put 3 shims on top of the planetary gear system and bolt it together. The purpose of that was to apply more pressure to the outer ring of the planetary gear system, giving it more resistance to slipping, and helping the starter function better. The outer ring is designed to slip in case of engine kick back. If it cannot slip, then engine kickback would be breaking pieces in the starter system.
Vacuum lines don't matter where they originate from, only where they terminate. My example would be if the petcock needed engine vacuum to open up and allow fuel to flow, it would not matter whether that vacuum came from the front cylinder or rear cylinder. Vacuum is vacuum and it is going to do its job, as long as it gets to the correct place. Both cylinders produce the same vacuum (providing they don't have problems of their own) so as long as you get it to where it is needed, it doesn't matter where it starts.
If the parts are still available, I would replace the intake boots with new ones. Air leaks at the intake will only exasperate an already finicky starting motorcycle. Also, to make it as easy to start as possible, you need to keep the valves in adjustment, as well as the carbs, sync, mixture and idle speed. "IF" everything is right, Viragos start pretty well. Start getting things out of whack, and they can be down right impossible. Another point or two to consider is to make sure you have sufficient tension on the wishbone spring on the gear under the left engine side cover for the starter clutch. The tension on that spring gives resistance to that gear from spinning which makes it kick out to engage the flywheel.
Another point, make sure the back of the flywheel gear isn't damaged beyond servicable use. If someone had not been maintaining the bike and just grinding away at the starter year after year, it will never engage properly so it is easy starting.
Here is a link to Yamaha's parts catalog where you can select the parts fiche for your motorcycle and then look at the individual components of each system. Especially check out the starter picture and starter clutch picture to see the items I mentioned.
Thanks and good luck!
Posted on Oct 05, 2009
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Jun 09, 2013 | Mercury Cougar Cars & Trucks
Jan 05, 2013 | 1999 Ford Contour
Aug 30, 2017 | 1999 Hyundai Accent
Jun 07, 2010 | 1999 Chevrolet C1500
Apr 27, 2010 | 1998 Oldsmobile Intrigue
Apr 11, 2010 | Sierra '03 - '06 1500ld/hd and 2500ld...
May 23, 2009 | 1996 Chevrolet Cavalier
Apr 19, 2009 | BMW 330 Cars & Trucks
Feb 02, 2009 | 1998 GMC Sierra
Dec 12, 2017 | Motorcycles
136 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: