660 Check it before it goes BANG!!!

[Chalks]

Hi All I've just stripped my spare Baggy engine and discovered the nut on the balance shaft was only finger tight with only the lock washer holding it on. No signs of wear or damage though. I've been reading on another forum the shaft can wear when this happens causing engine damage. My next job is check the nut and use thread locking compound on the motor I'm running.

[DAVID THOMPSON]

all owners of this engine need to read this group of posts and i mean the whole thing
it is very important to the health of both your engine and your pocket book
as it can turn you nice bike into a "parts bike in seconds

viewtopic.php?f=3&t=5215&hilit=balance+gear

dave

[den]

so how easy is it to check,,Whats got to come off?? Any photos

[den]

Hi All I've just stripped my spare Baggy engine and discovered the nut on the ballance shaft was only finger tight with only the lock washer holding it on. No signs of wear or damage though. I've been reading on another forum the shaft can wear when this happens causing a knock when running. My next job is check the nut and use thread locking compound on the motor I'm running.

post a photo of the offending area maty--A picture speaks a thousand words

[handsomejackuk]

yep need a photo of how to check this plaese and a dsecription

[DAVID THOMPSON]

read the post in the link i gave above about the whole thing

there are pictures and part numbers included
dave

[den]

now im worried,, I bought this bike becaus of the engine being "bullet proof" . now it seems its not??
Just what are the chances of me finding the nut loose and averting an engine explosion,,50/50?/ 10 to 1 ?? odds on or evens

[DAVID THOMPSON]

do not weigh the odds FIX IT
dave

[Chalks]

I think Dave is right Den, prevention is going to be a lot less hassle than repair after it's too late. It's a full strip down to change the balance shaft should the unthinkable happen. I didn't take any photos and my spare motor is now completely stripped now but these are from the other thread:

The large nut on the toothed pully at 12 o'clock is the balance shaft (which was loose). The other pully to the right is a replacement (from a Yamaha 700 Raptor) that will cure our problems (Yam part number 1S3-11536-00). Thanks for the info Dave.

[Chalks]

The spring loaded pully on the right is the offending article! (Replacement on the left).

I think the repair sequence will go something like:
Order new pully (700 Raptor), lock washers & clutch cover gasket,
Drain oil & coolant,
Remove clutch cover (right hand engine casing) and water pump,
Remove clutch,
Remove and replace spring loaded crank pully and lock washer,
Remove balance shaft nut and replace lock washer,
Replace nut and washer using thread locking compound,
Tighten, tighten & tighten some more.
Rebuild,
Feel reasured that your engine will live longer than you!

[den]

Thanks for the photos , easy enough job now i can see whats involved,,i got two questions
why the need to change the spring pully for a solid raptor one??
will i need to buy a gasget for the cover , pt,number anyone??

[Chalks]

Apparently the back and forth action of the sprung pully batters the fixed pully on the balance shaft that can cause this:

balancer_damage[1].jpg (18.01 KiB) Viewed 15221 times

The gasket is optional but if you use the old one and it leaks you've got the job to do again.

[den]

Searching for the drive gear in the tinternet is hard , even though the part number is correct most websites just want the bike make model and year info mm,stump,,what year raptor,Anyone know /have direct link..yamaha parts in uk?
im not lazy just stuck,, want to price the job up while the bikes laid up for winter

[cat]

freaking google it man! No wonder Bill got so frustrated.

http://lmgtfy.com/?q=yamaha+%221S3-11536-00%22

and if you don't like all the american /raptor links in the results, then read the thread that David posted the link to and order the XT660R/X part.

[duncmac]

For the UKers here the following might be helpfull.

From Bill post

balancer gear Raptor 1S3-11536-00
Balancer gear XT660R 5VK-E1536-00 £74.76 [url]http://www.yamahamotorcyclespares.co.uk/spares/search.asp?search=5VK-E1536-00&genuine=&aftermarket=&universal=1&uID=0
[/url]

Slipstream tuning also do this 16- Solid balancer gear £100