Yamaha SRX600 : Fixing 5th gear 

Good luck with the gearbox repair. I've noticed you are also on our Facebook group. Feel free to ask questions or share you experiences there. plenty of expertise on the group.

Glad you like it Bernard. Thanks for your comment

Nice bike. Good luck with the repair. Once repaired the bike can do many 1000km's again.

Glad that this video could be of help. Good to hear your bike is on the street again.

Press fits are not uncommon on gearboxes. It's a very tight fit. Perhaps it looks easy on the video but it takes a considerable force to remove and install 2nd gear.

@@U2pSandman Sure thing. I'll have to get a puller. Your video is really helpful. Thanks again.

Hi Luke i can't think of a M6 nut that belongs inside the crankcase or clutch or dynocover. I've rebuild a few engines but nothing comes to mind right now. You could crosscheck the partslists and engine diagrams to search for a possible source. cmsnl.com or megazip.net have partslists and diagrams for the SRX engine online. Perhaps someone accidentally dropped it in the engine and thought or hoped it wouldn't cause problems.

Hi Conegan99, There is no keyway on 2nd gear on the inputshaft, it's an interference fit. If 2nd revs out on the inputshaft that's obviously not good. Could be that your inputshaft is worn out (smaller OD ) or the ID of 2nd gear is worn out. Best to measure both with a micrometer and either replace the inputshaft or 2nd gear

I could never do this

Hello Karola, I buy parts at kedo.com in Germany and cmsnl.com in the Netherlands most of the time. You should also be able to order these parts with a local Yamaha dealer. Partnumbers are in the video. Good luck with the repair.

One of the gears I could not get from Yamaha. Check your motorcycle salvage. I was lucky. Also, check eBay for anyone selling their bike for parts. There's a guy in the U.S. parting out his bike right now and the gear set is for sale. Let me get you the link. This is a search using 1986 Yamaha SRX600. This was not a cheap repair for me but this bike had already been a labor of love. I've probably spent 3 times what the bike was worth already. www.ebay.com/itm/Yamaha-600-SRX-SRX600-Engine-Transmission-Shift-Forks-1986-YB338-TD/401992574394?_trkparms=ispr%3D1&hash=item5d989fe5ba:g:xPMAAOSwjCBd6FiL&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qUAVjME%2Fj8jfS9a6XQJBew5qPZ2zsmL26zPf5Q6ngQ74%2B%2FuVHbOw2qqaphtZxvjcHwwUkfKDWNROdA4kva5unNpY%2BMTip%2B1UlKMXB4IIDjX9wu2SRtFLeENxvmWZMs%2BOjhlAp%2F5Tg765eXclMzXiE5BaSL4NH4EPEH4AHIc%2FjpL1HcsgXk4gQUDalWRChSQzSbaMZhFoP8euZptKx7zH9P2WXPq0pajJweZacj0DLX35bS1tw7DZZ9hBn8w9QrlMQLFS1A95uK6vb703Bn4nAZgSSTeioJPyQcR0eM5MP2y%2FbC9xNYpUvaQddoTgKeRWLnXyIJ41i%2FcCTrOLyTb6VMrA7Hw96itQVdDTDNtC7fzRfMnAAv5RLS7yddDFQcPi9Y7BrD0zl4l31NKmkxsu6ncxcNpf9TH5Dc771wiw1tP6dSY72vR5Ohw%2Fbi4Etts89ew1Fex6K5lTvii2q7NwZn4JKbY90YQCuOoBM4gQIvXcPBz5%2BbtZjg3riHJ87ki2XDKskls4cq6P21YdVhl5nqCcssNoC9ZFX9UkYYaR2zU0RjrJ7jf8oQC%2BhVL3ztLtYxCY72JMnzElgUkCvXlPaGqMVs0hfok%2FKXftLO7W%2BVtcX4OZh8AUpM4P8L%2BBj4v8bpii7%2FJqjE4JUGHOcz0u3Mh%2FCMD6SSCm53c8URziyea8tSa%2FlK%2FU4GXNCXobj2XkkJeaUskjWTJo04CvF88LE1az%2BlaV04FQJf7jzKbv1AAip8eJ6nuqsO2hgLC1yuaFyw%3D&checksum=4019925743944af8396c6e6b4f3ea4ce6c1d15cd0cc7

@@Wabbit1961 ha ha. I know the feeling....All that money, now you'd better get good use out of your bike!

Thanks for your reply. Yes it's more than strong enough. All SRX/XT/TT/XTZ/SZR gearboxes have a pressfit for 2nd gear. The gears are new and sourced from Yamaha. I don't know of an alternative gear manufacturer that produces gears for this gearbox. Having them custom made would probably be even more expensive.

I have a problem where 2nd gear is rotating on the input shaft. I will have to make a keyway and shim

@@ConEgan99 See my answer on your other comment. I think it will be very challenging to make a keyway on the inputshaft. Note that the shaft is hollow because the clutch pushrod is inside the input shaft too. This means there is not a lot of meat to machine a keyway on the shaft...

@Wabbit1961 that difference in speed between both gearsets is very little. The ratio is what matters and they are close. the standard 27/21 set does 160Km/h at 6000rpm in 5th. The 24/19 set does 157km/h at 6000 rpm in 5th. You can do the math yourself and you'll see it doesn't matter much.

@@U2pSandman RPM at 70mph is just over 4krpm. The new gears dropped rpm a good 500. The bike is noticeably more relaxed in 5th on the highway at 80mph. I don't mind that at all. I'm also running 90 instead of 80 for the tire 'height'. That also drops rpm a good 500. (Rear is 120/90/18 instead of 120/80/18 - more matched pair tire choices.) Sometimes I'll run a 90/90/18 front. That really makes the bike want to lean quickly. Conti Attack tires are a good radial choice on a bike doomed for mostly a bias ply tire selection. Do you still own yours?

@@Wabbit1961 I have 4 SRX'es 2 in a running state, one project i am currrently rebuilding. the 4th is for spares or perhaps a track bike in the future. The numbers i mentioned are with standard tyre dimensions. Tyre size affect numbers as well indeed. I created a calculator in excel to see what the impact of the changed 5th gear ratio would be. I use Bridgestone BT45's in standard size on both the running bikes.

@@U2pSandman I found that set of tires had good traction, for about 2,000 miles. Then the rear gets hard in the center and loses grip. I put 8,000 miles on the Conti tires. You don't happen to know anywhere I can get a new gas tank?! Mine is ok but it's been creamed twice already.

@@Wabbit1961 Tanks are unobtanium unfortunately. Either fix them if the rust is not too bad or braze them if there are pinholes. Some folks on our SRX600 facebook group had new tanks made. Tanks is a frequently recurring topic on our group. A few times per year someone offers a tank for sale on our FB group, but it's not very often. Fill the tank up when you park the bike for longer time and siphon the water out of the bottom pockets of the tank once in a while. Water tends to collect in the bottom of the tank....

There is quite a bit of pressure on the puller indeed. You need a strong one. The first part is the hardest, once it starts moving it will go. Heating the shaft with a paintstripper might also help. Good luck.

@@U2pSandman What about a blowtorch on the 2nd gear? I'm afraid to damage it... Considering they aren't the best quality from factory (or we wouldn't be replacing them)

@@DoubleYouPee1 I wouldn't expose the gears to direct heat from a blowtorch. The temperature of a torch is way too high and might change the temper of the gears. Better use a paintstripper or put it in a kitchen oven at 80 degrees C. Other tip : Put some tension on the puller and then gently tap with a hammer on the top of the puller. The shockwaves may help to break the gear loose. Once it's going, it's going...

@@U2pSandman Thanks, I got it off just today. Put the blowtorch on it for only 30 seconds to the front of the 2nd gear (tried to not hit the teeth), then cooled the axle with freeze-spray. Came right off. Didn't want to kill my new puller 😕. I think the 30 seconds didn't do any damage (at least I hope so). Putting it in the oven heats the entire axle, also it would be extra hard to use the puller when its 100c.

@@DoubleYouPee1 Good to hear you got them off. with an oven or paintstripper It's true you would heat the entire shaft including gears, so both gear and shaft will expand a little. it can be enough to overcome the initial friction. I recently removed the timing gear from a crankshaft which has an even tighter interference fit, just by heating the gear to 80 degrees. Freeze spray to cool the shaft is also a good idea. I have used that as well for other purposes.