I am stripping an engine and the sprag clutch was really jammed.
If you look at the way the bearing assembly has been bent, this sprag kicked back big time! Can't believe it wasn't giving out audible warning signals to the owner well before this happened.
I have found the best way to safely unjam the sprag is to pad the vice jaws to hold Gear3, put a couple of bolts in the sprag and turn it anti-clockwise with a bar.
It's quite common on bikes that owners try to start repeatedly with flat batteries. The kickback when there's not enough juice to get past the compression stroke causes the problem. I've also seen it on Yamaha and Honda farm quads that are left long periods and abused!
I also think poor servicing can be a factor with metal particles in old oil damaging the surfaces.
I recently posted the replacement of my sons Sprag,
I live in Australia and the cost to purchase genuine Yamaha "STARTER ONE-WAY ASSY Part #: 4GY-15590-00" was over $312 AUD, I didn't want to go for aftermarket although temping for half the cost. I went to Partzilla in the USA and purchased Genuine for $112USD plus $40 USD postage total $152 USD converting to AUD was $215
Hopefully Part in the UK don't have the added mark up. Otherwise this purchase option may save you some money
I recently posted the replacement of my sons Sprag,
I live in Australia and the cost to purchase genuine Yamaha "STARTER ONE-WAY ASSY Part #: 4GY-15590-00" was over $312 AUD, I didn't want to go for aftermarket although temping for half the cost. I went to Partzilla in the USA and purchased Genuine for $112USD plus $40 USD postage total $152 USD converting to AUD was $215
Hopefully Part in the UK don't have the added mark up. Otherwise this purchase option may save you some money
Grahame
Thanks for the info I got my sprag and gears from partzillar
Only took two weeks and saved time and money on buying from yamaha Australia
Ttboof
I should have bought two, postage would not have been much more and that would have covered part of the cost selling here, for even a discounted price compared to the Australian Yamaha Parts to another person
Ttboof I should have bought two, postage would not have been much more and that would have covered part of the cost selling here, for even a discounted price compared to the Australian Yamaha Parts to another person
I'm happy with the deal from partziller . Thanks again for the heads up . Your idea of adding to your order would be good .
I had held off too long and stuffed my starter as well but was lucky a second hand one was on ebay so all genuine parts fitted and it's all good.
All I can say if in doubt replace the sprag it's far cheaper than waiting (mine lasted 90 000 km ) but had to replace everything
I recently purchased a 2000 model TTR which had the loud clacking sound when starting and stopping.
Today I removed the parts to get the sprag clutch out and found all looked very good with no visible wear or damage to anything, including the sprag clutch.
Having searched and read up on this issue I decided it best to replace the sprag clutch whilst everything is apart and started looking for a reasonable price here in Australia, not going to happen with prices from Yamaha dealers ranging from $315-$499 so I looked elsewhere, Aliexpress almost got my cash but wasn't feeling it, found genuine parts on Webike Japan at very reasonable prices and ordered a replacement. japan.webike.net/products/24686755.html
Total cost including freight with EMS Post to Australia of $180 including Paypal fees.
A very good price and hoping it arrives in the next couple of weeks.
The bike hasn't had much use in the past ten years and next to none over the past two, so I will fit a new battery at the same time to make sure the starter is spinning up well when starting the bike.