gearbox swapout
Sat May 22, 2010 7:36 pm
After talking about it for over a year it's finally done!
The '87-'94 500's had a fairly major issue with a poorly made bearings in the 'box - after about 50,000kms it would get to the point where it would refuse to go into 2nd while accelerating then slipping out of 2nd into neutral on engine braking. Fairly major PITA.
Solution - fit a 'box from a later model. In the US & UK you can still buy a GPZ500 (EX500) new so the later gearbox was fairly easy to get hold of - I got a 2005 model ;box with approx 10,000miles on it for $145 delivered.
The swap is fairly easy to do but I lacked a fair bit of confidence in doing it all myself. Thanks to supra supra coming over and helping me drop the motor out (easier than expected) I was able to take it out to Michael @ MS Motorcycle Repairs (Londonderry) - he did the actual swap for me. The swap is fairly straightforward - remove the oil pan and clutch, split the cases, lift out old 'box and insert new 'box, reassemble. Head doesn't need to be touched and neither does the cam chain
supra supra then came back and fitted the motor back into the frame (way more difficult than removing).
Over the last week I've managed to refit everything back into place, done some mods for fueling and replaced a couple of broken parts. Disco & GPXpunk came over today and helped with the final bits before we fired her up.
After a quick adjustment of the new clutch cable and running it until it was hot, checking fluid levels etc it was time for a test ride - out to Wisemans Ferry and back.
First up - the 'box is excellent! Nice and positive gear changes happening and no false neutrals.
Secondly - the fueling mods have worked amazingly well!! Instead of power kicking in at 7000rpm it's now available from 4000rpm all the way up to redline.
Few little things to do yet - check the chain tension and do the "string thing" to check alignment and find a small oil leak then its finished!
Thanks to GPZ_Jim for kindly supplying a couple of parts as well - really appreciate it
With only 97,800km on her she's going pretty damn well
The '87-'94 500's had a fairly major issue with a poorly made bearings in the 'box - after about 50,000kms it would get to the point where it would refuse to go into 2nd while accelerating then slipping out of 2nd into neutral on engine braking. Fairly major PITA.
Solution - fit a 'box from a later model. In the US & UK you can still buy a GPZ500 (EX500) new so the later gearbox was fairly easy to get hold of - I got a 2005 model ;box with approx 10,000miles on it for $145 delivered.
The swap is fairly easy to do but I lacked a fair bit of confidence in doing it all myself. Thanks to supra supra coming over and helping me drop the motor out (easier than expected) I was able to take it out to Michael @ MS Motorcycle Repairs (Londonderry) - he did the actual swap for me. The swap is fairly straightforward - remove the oil pan and clutch, split the cases, lift out old 'box and insert new 'box, reassemble. Head doesn't need to be touched and neither does the cam chain
supra supra then came back and fitted the motor back into the frame (way more difficult than removing).
Over the last week I've managed to refit everything back into place, done some mods for fueling and replaced a couple of broken parts. Disco & GPXpunk came over today and helped with the final bits before we fired her up.
After a quick adjustment of the new clutch cable and running it until it was hot, checking fluid levels etc it was time for a test ride - out to Wisemans Ferry and back.
First up - the 'box is excellent! Nice and positive gear changes happening and no false neutrals.
Secondly - the fueling mods have worked amazingly well!! Instead of power kicking in at 7000rpm it's now available from 4000rpm all the way up to redline.
Few little things to do yet - check the chain tension and do the "string thing" to check alignment and find a small oil leak then its finished!
Thanks to GPZ_Jim for kindly supplying a couple of parts as well - really appreciate it
With only 97,800km on her she's going pretty damn well
Re: gearbox swapout
Sun May 23, 2010 5:05 pm
no worries glad to help.. good practise for if I need to do some of that stuff to mine too
glad to help.. good practise for if I need to do some of that stuff to mine too