Folks,
Just got home and what was a nice ride on my GT550B but ended very badly. It definitely could have been worse. 30miles into the ride, it started making noises that were not normal but, thinking it was exhaust gasket making it feel like it was running on two, and as I was near home, I crawled along hoping to make it back. Bloody thing locked up solid and slid for 15-20 feet, about 1.5 miles from home. I suppose I should have stopped as soon as it sounded odd.
Managed to push it home and popped it in the workshop for a post mortem another time. You will no doubt be hearing anguished cries from the wallet.
Cheers,
Mike
Disaster GT550B
-
yeadon_m
- Posts: 7401
- Joined: Sat Jan 02, 2010 7:10 am
- Location: Canterbury Kent
Disaster GT550B
- Attachments
-
-
-
crazy4557
- Posts: 550
- Joined: Sat Dec 07, 2013 1:24 pm
- Location: Lymington, Hampshire
Re: Disaster GT550B
Oh, that's not good at all. Hoping it's not too serious but fear it could be.
Interested to hear the prognosis so I can be aware on mine. I'm 86 miles in on my running in schedule and still a bit tetchy just in case the same might happen.
Interested to hear the prognosis so I can be aware on mine. I'm 86 miles in on my running in schedule and still a bit tetchy just in case the same might happen.
1976 GT550A in black
-
JOHNJENKS66
- Posts: 1263
- Joined: Mon Apr 11, 2011 8:38 pm
- Location: Cork City Ireland
Re: Disaster GT550B
Mike,sorry to hear about this,hope your ok ?? Bikes can be fixed up,our skin and bones can be a little harder to put right.
How many miles have you put up,since rebuilding the engine,as I know you had trouble with the bore/pistons for a good while.
Regards,John.
How many miles have you put up,since rebuilding the engine,as I know you had trouble with the bore/pistons for a good while.
Regards,John.
what the fuck was that ????
If you can read this, thank a Teacher.. If you are reading this in English, then thank our Soldiers..
If you can read this, thank a Teacher.. If you are reading this in English, then thank our Soldiers..
-
yeadon_m
- Posts: 7401
- Joined: Sat Jan 02, 2010 7:10 am
- Location: Canterbury Kent
Re: Disaster GT550B
John,
The rebuilt motor minus the left pot has done ~800 miles, the replated left about 200. I am certain the timing, carbs and lubrication were fine 200miles ago and, until today, its run perfectly.
Lord knows what has happened but its pretty terrible if at low speed it caused the running motor to lock up solid. I cannot recall if I pulled the clutch but I might have had my hands full slaloming! I'll whip off the head tomorrow and see what I shall see. I doubt its 'box as I could push it easily in neutral and the noises sounded motor, not drive.
I can see this going round again from scratch, and I was never happy with SEPs crank rebuild, with KTM200 rods (too long). Its long occurred to me I might have damaged lower end bearings running it before I realised that a squish clearance of exactly zero isn't smart and installed 1mm thick base spacers. Who knows, perhaps something nasty happened in the bottom end and a needle bearing finally exploded. As you say, it can all be fixed, its only money (sob) and not medical. If I dig right in again, this time I will split the cases and send bits off myself. I will feel I have more control that way and I'll also learn more. I have a spare set of original nikasil cylinders (from Steve r here) so it should all be doable.
I was lucky not to have been pitched off 10min earlier when, headed down the A road I was at 70mph in top. Hardly bears thinking about.
Lesson - do not ignore odd noises, not even for a few seconds. I've thrashed plenty of strokers in my youth but never had this in over 60K miles on them!
Cheers,
Mike
The rebuilt motor minus the left pot has done ~800 miles, the replated left about 200. I am certain the timing, carbs and lubrication were fine 200miles ago and, until today, its run perfectly.
Lord knows what has happened but its pretty terrible if at low speed it caused the running motor to lock up solid. I cannot recall if I pulled the clutch but I might have had my hands full slaloming! I'll whip off the head tomorrow and see what I shall see. I doubt its 'box as I could push it easily in neutral and the noises sounded motor, not drive.
I can see this going round again from scratch, and I was never happy with SEPs crank rebuild, with KTM200 rods (too long). Its long occurred to me I might have damaged lower end bearings running it before I realised that a squish clearance of exactly zero isn't smart and installed 1mm thick base spacers. Who knows, perhaps something nasty happened in the bottom end and a needle bearing finally exploded. As you say, it can all be fixed, its only money (sob) and not medical. If I dig right in again, this time I will split the cases and send bits off myself. I will feel I have more control that way and I'll also learn more. I have a spare set of original nikasil cylinders (from Steve r here) so it should all be doable.
I was lucky not to have been pitched off 10min earlier when, headed down the A road I was at 70mph in top. Hardly bears thinking about.
Lesson - do not ignore odd noises, not even for a few seconds. I've thrashed plenty of strokers in my youth but never had this in over 60K miles on them!
Cheers,
Mike
-
yeadon_m
- Posts: 7401
- Joined: Sat Jan 02, 2010 7:10 am
- Location: Canterbury Kent
Re: Disaster GT550B
Crazy,
I will do my very best to find out why this has happened and report back. If I cannot, I don't think I'll ever feel completely safe riding it. If its a lube, carb or ignition fault, it would probably recur even with a brand new motor.
The 380 and 750 rebuilds have each done well over 2000 miles and sound great, so I don't mind chin on the clocks stuff, but I couldn't do that on a bike which once seized on me unless I find and fix the initiating event. Also, my wife was whiter of face than I was when I told her what had happened as I arrived home bathed in sweat. Ever tried pushing a bike a couple of miles up and down hills while still wearing all your gear in summer? I had no where to put it. Being a distance runner I didn't care, I decided to 'enjoy the experience' no matter how hot I got (but I am a little touched
)
Take care out there. I don't think this is common, these triples are generally considered very tough.
Mike
I will do my very best to find out why this has happened and report back. If I cannot, I don't think I'll ever feel completely safe riding it. If its a lube, carb or ignition fault, it would probably recur even with a brand new motor.
The 380 and 750 rebuilds have each done well over 2000 miles and sound great, so I don't mind chin on the clocks stuff, but I couldn't do that on a bike which once seized on me unless I find and fix the initiating event. Also, my wife was whiter of face than I was when I told her what had happened as I arrived home bathed in sweat. Ever tried pushing a bike a couple of miles up and down hills while still wearing all your gear in summer? I had no where to put it. Being a distance runner I didn't care, I decided to 'enjoy the experience' no matter how hot I got (but I am a little touched
)Take care out there. I don't think this is common, these triples are generally considered very tough.
Mike
-
mizzytheman
- Posts: 2227
- Joined: Tue Dec 28, 2010 1:17 pm
- Location: Knowsley, Liverpool
Re: Disaster GT550B
Hi Mike,
Sorry to hear the bad news. Hope it's a simple fix. Main thing is you're ok.
Regards
Martin
Sorry to hear the bad news. Hope it's a simple fix. Main thing is you're ok.
Regards
Martin
-
Rhencullen
- Posts: 715
- Joined: Tue Dec 13, 2011 7:10 pm
- Location: Lincolnshire
-
Alan H
- Posts: 12116
- Joined: Fri Aug 05, 2011 6:38 am
- Location: Wombwell, Republic of South Yorkshire
Re: Disaster GT550B
Bloody Hell Mike, that's bad news. Good to hear that you are OK though.
Metal can be fixed.
Metal can be fixed.
Proof that four strokes are over complicated
-
canaletto5
- Posts: 5228
- Joined: Tue Jul 23, 2013 8:43 pm
- Location: Derbyshire
Re: Disaster GT550B
Heart stopping stuff Mike, thank goodness you're ok mateyeadon_m wrote:Crazy,
I will do my very best to find out why this has happened and report back. If I cannot, I don't think I'll ever feel completely safe riding it. If its a lube, carb or ignition fault, it would probably recur even with a brand new motor.
The 380 and 750 rebuilds have each done well over 2000 miles and sound great, so I don't mind chin on the clocks stuff, but I couldn't do that on a bike which once seized on me unless I find and fix the initiating event. Also, my wife was whiter of face than I was when I told her what had happened as I arrived home bathed in sweat. Ever tried pushing a bike a couple of miles up and down hills while still wearing all your gear in summer? I had no where to put it. Being a distance runner I didn't care, I decided to 'enjoy the experience' no matter how hot I got (but I am a little touched
Take care out there. I don't think this is common, these triples are generally considered very tough.
Mike
-
Roger Ackery
- Posts: 3693
- Joined: Wed Jul 20, 2011 3:40 am
- Location: Sydney NSW Australia
Re: Disaster GT550B
Hi Mike,also concerned for your safety...as you said these bikes are normally very tough & reliable & are not known for this sort of behaviour 
I do wonder,like you,if it all relates back to the earlier motor repairs 
Cheers,
Roger
I do wonder,like you,if it all relates back to the earlier motor repairs Cheers,
Roger
Cheers.
Roger
GT750A.
Roger
GT750A.