To start or not to start?
Fri Feb 26, 2010 8:46 pm
Well carrying on from my 'getting started' post I've discovered both the 82 and 83 will turn over by hand. Followed waynes advice and put some oil in the cylinders and that got them moving ,although turning the back wheel didn't seem to do it.. (wasn't sure if i was actually getting them into top gear or not) so took of the timing cover and turned them from there.
With the spark plugs back in they still turn with an obvious compression factor evident (although how much i don't know). I'm guessing that if the pistons move it might be possible to run the engines? However when taking the plugs out initially i noticed in one bike what appeared to be some loose grit inside (on top of a piston?) and another looked a bit pitted (rust?). Wondering if they actually could start wether i should try or not. If there is crap in the cylinders and they start, could it stuff them completely? Or should I strip down the engines clean and check them fully first?
nick
With the spark plugs back in they still turn with an obvious compression factor evident (although how much i don't know). I'm guessing that if the pistons move it might be possible to run the engines? However when taking the plugs out initially i noticed in one bike what appeared to be some loose grit inside (on top of a piston?) and another looked a bit pitted (rust?). Wondering if they actually could start wether i should try or not. If there is crap in the cylinders and they start, could it stuff them completely? Or should I strip down the engines clean and check them fully first?
nick
Re: To start or not to start?
Fri Feb 26, 2010 10:11 pm
if you start the motor with crap sitting on top of the piston it may damage the head / bores / rings etc - in other words, the motor.
IIRC getting the heads off isn't that difficult. Do you have a workshop manual for it? That should give you the details you need. The only thing is if you're going to do that you may as well rebuild it depending on what you find.
.
Whats the overall plan? Get the bike rideable ASAP with minimal work and rebuild later or rebuild the bike from the ground up - a full restore job?
Possible costly option - give it a go and see if it starts. If it starts and runs then run it for 15 minutes (you've checked for coolant in the radiator before starting it haven't you?) then drain the oil. Use a magnet to go thru the oil and see if any metal fragments come out or filter it slowly thru a coffee filter. Fragments = problems. Mayonnaise = problems. Clean = good - move to next phase.
Costly option - drop the motor out and rebuild it - you then know you have a rebuilt and hopefully reliable motor.
This is just my opinion and may be completely off base or cause more damage - as before there are way more knowledgeable people here (once they're back from PI) who will have better advice.
Just a thought tho - instead of multiple threads just try to keep it to one so everyone can follow without jumping from thread to thread
IIRC getting the heads off isn't that difficult. Do you have a workshop manual for it? That should give you the details you need. The only thing is if you're going to do that you may as well rebuild it depending on what you find.
.
Whats the overall plan? Get the bike rideable ASAP with minimal work and rebuild later or rebuild the bike from the ground up - a full restore job?
Possible costly option - give it a go and see if it starts. If it starts and runs then run it for 15 minutes (you've checked for coolant in the radiator before starting it haven't you?) then drain the oil. Use a magnet to go thru the oil and see if any metal fragments come out or filter it slowly thru a coffee filter. Fragments = problems. Mayonnaise = problems. Clean = good - move to next phase.
Costly option - drop the motor out and rebuild it - you then know you have a rebuilt and hopefully reliable motor.
This is just my opinion and may be completely off base or cause more damage - as before there are way more knowledgeable people here (once they're back from PI) who will have better advice.
Just a thought tho - instead of multiple threads just try to keep it to one so everyone can follow without jumping from thread to thread
Re: To start or not to start?
Fri Feb 26, 2010 11:53 pm
Cheers wayne. Overall plan..well that's a good question. Originally wanted to try and do a full rebuild just for the challenge but now i've seen these pistons move I want to get the little suckers thumping . Also if one (or both of them) happen to run ok, I guess there's less chance of stuffing it up by pulling them completely apart..
I think i'll try to start them and see how I go
. Also if one (or both of them) happen to run ok, I guess there's less chance of stuffing it up by pulling them completely apart..I think i'll try to start them and see how I go
Re: To start or not to start?
Sat Feb 27, 2010 9:58 pm
Anybody got a different copy of the ZX750 manual(s) to download? I downloaded a version at http://kz.mbsween.com/manual.html (thanks dub) but the bottom of many of the pages are cut off
Re: To start or not to start?
Sat Mar 13, 2010 9:38 pm
Well back to the bikes.. geez work is an annoying distraction in my life!
So I have tinkered around with a few different things working out how bikes actually work and been doing a bit of reading and have decided to work on the electrical circuits first. As far as I can see i cant do much without a power supply! Of course I'm already confused
I'm trying to work out the wiring in and out of the junction box . On the bike itself (on the 83) there are two separate connectors with 3 wires in one and a larger connector with 12 wires. This seems to match what i see on the overall wiring diagram ..
http://kz.mbsween.com/media/ZX750-A1-NonUS.jpg
however in the supplement for the the 83 model there is a junction box diagram (on page 357 of the manual..comes up as page 355 on my Adobe reader)
http://kz.mbsween.com/media/GPz750-full.pdf
which shows 3 separate connectors (total of 24 wires).
On the actual junction box on the bike again there is a place where a 3rd connector could be plugged but there seem to be no missing wiring coming from anywhere that could plug there?
Can anyone explain this to me?
Nick
So I have tinkered around with a few different things working out how bikes actually work and been doing a bit of reading and have decided to work on the electrical circuits first. As far as I can see i cant do much without a power supply! Of course I'm already confused
I'm trying to work out the wiring in and out of the junction box . On the bike itself (on the 83) there are two separate connectors with 3 wires in one and a larger connector with 12 wires. This seems to match what i see on the overall wiring diagram ..
http://kz.mbsween.com/media/ZX750-A1-NonUS.jpg
however in the supplement for the the 83 model there is a junction box diagram (on page 357 of the manual..comes up as page 355 on my Adobe reader)
http://kz.mbsween.com/media/GPz750-full.pdf
which shows 3 separate connectors (total of 24 wires).
On the actual junction box on the bike again there is a place where a 3rd connector could be plugged but there seem to be no missing wiring coming from anywhere that could plug there?
Can anyone explain this to me?
Nick