gpz1000rx barn find

[welshphill]

hope this is ok, admins please delete if gpz's aren't allowed

i'm about to pick this up on sat, as a rolling, recommisioning project. going to ride her n get her back to nice, shiney, serviced, etc. she doesn't need much. just the usual refurbing, cleaning, greasing. coppa slipping that comes with being parked up for 10+ years....



i think it's an early one, she's on a C reg with 22,000 miles

anything to look out for on this model, are there many left on the road??

[Nosher903]

I had a go on Powerbiking's demo of those when they came out in '86, so C reg sounds right for a first year model. I wound it up along the A5 in Milton Keynes. It was ludicrously fast compared to the GPZ750R I had at the time. I never liked the look of it though.

I've got a GPZ900R now. I think it's fair to say you have to look out for the same things on the 1000RX which became faults on the 900R which were -

Revised cam chain tensioner and blade, revised oil feeds to the inlet cam to stop the cam pitting. All that should have been fixed under warranty. They may have had the carb icing problem - again should have been fixed under warranty. Then big end bearing No3 can go. I believe it's an oil feed problem. A lot of guys with 900s (including me) pull the sump off and put a ZZR1100 oil pressure relief valve on the oil pump. The standard spring goes soft with age and lets the oil pressure drop too low. Good luck with it.

[welshphill]

thanks for the info,

i'm going to upgrade the cam chain tensioner to zzr1100

i'll look into changing the oil pressure relief valve too, is it engine out or can it be one ''in situ''

i'd like a manual on pdf file/download one, any ideas where i ould find one???

[Nosher903]

You could do the OPRV with the engine in situ. It would be very fiddly though.

I did it engine out which is a doddle with GPZ900s due to the spine frame. I was doing a fairly major resto though, so it suited my purposes to do it that way in any case.

I think you could do a lot worse than join the GPZ900R forum which costs £5 a year. There's a huge amount of expertise about the 900/1000 engine. It's because it's a simple swap to put one into a 900R.

Hope this helps you out.

[welshphill]

picked up my gpz thou today, stripped off some bodywork. popped some jump leads on her, hooked her up to a remote fuel res n pressed the starter...

https://www.youtube.com/watch?v=K1frRLWte3Y

tanks rusty inside, carbs are crudded right up, surprised she started at all... got the carbs off, stripped out the jets, float valves, needles, etc. they're soaking in coca cola overnight

[mick znone]

nice one Phil, that bottom picture is SOO Wales
my dear old mum was from the green land. good luck with the build.

[mick znone]

now that sounds ropey Phil but great camera to presenter action

[welshphill]

we are VERY welsh here in pontypool, Mick...

the idea behind a start up was to see if the bugger would, make sure i wasn't wasting my time on a blown motor and give me an idea of what to clean or refurb

she only caught on 2 cylinders, but with a little tickle of the throttle i got 3, poss 3 n a half cylindres firing

on inspection, the carbs are really crudded up with 'old petrol tar' and the idle jets on 3 carbs were seriously blocked

i'm thinking about upgrading the carbs to zrx, but would like to know what other carb options are about for the 1000rx

anyone have any ideas on carb options???

[welshphill]

rebuilt the carbs today, found everything was pretty crudded up,

but main probs were 3 idle jets blocked, one sticky float and all the mixture screws all over the place.

after a good overnight coca cola bath all the jets, floats etc. are now free n clean, mixture screws are 1 n half turns out,

tomorrow is refitting and see what she runs like b4 getting the vacuum gauges out......

[mick znone]

another video clip to of starting Phil

[welshphill]

i was hoping to do one fella...

but refitting the airbox has proved to be a right PIA, i've ended up dropping the rear subframe to gain more access/wiggle room

but u need 14 fingers, extra small hands and the strength of the insane, almost chucked the airbox across the garage a few times and even looked on ebay at the price of KnN filters

so tomorrow, i'm gonna try a new tactic (the old one of shouting n cursing hasn't worked so far) and fit the airbox onto the carbs, off the bike. hold the two together with some cable ties n refit the whole lot as one

new rubbers would defo help, but my trusty heatgun is doing a nice job of softening em up...

but on the plus side, dropping the rear subframe, gave me good access to the shock linkages n they got a good grease up, along with the rear wheel spindle/bearings. then i spent a bit of time freeing up n coppa slipping the rear caliper. so thats the back end pretty much sorted

[welshphill]

after leaving the rx to stew n have a think about herself for a week, i eventually got the airbox back on...





replaced the rear subframe, batt box, etc. n went for a start up

https://www.youtube.com/watch?v=BpL0igK ... e=youtu.be

still running rough on about 3/3 n half cylinders, changed the plugs, checked the stator, pick ups, etc. turns out it's a very weak spark to 1 n 4 from a coil breaking down

hence the white smoke from semi unburnt fuel being chucked out

[welshphill]

as i'm waiting on a new coil, i thought today was sorting out her other running issues, got her as nice as i could (given the dodgy coil) on 3 n half, almost/sometimes 4, but the bugger was popping from what sounded like a hole from the pipe underneath, as i wanted to re-grease the headstock bearings n already bought fork seals i thought i'd best drop the front end n pipe off...





had a good look at the pipe n rear silencers, found a few 'pin holes' in the link pipe, so got me grinder out to find the good metal... i didn't find much!!!! what is there is too thin n crap to take a weld (even on the lowest setting n going gasless)



i'm going to try sleeving it, hoping the thicker metal top n bottom will play ball... kill or cure, i either save money or i buy a new pipe

[Rhencullen]

The exhaust balance pipe is always a weak point on GPZs Phil. My GTR even has stainless headers welded onto the same mild steel 4 - 2 ' collecter ' pipe section. It still rusts the same as yours has, but the headers are mint

[welshphill]

same as fella, the rest of the pipe inc the headers are realy quite good, but the link pipes rotten, i'm not the first to weld/plate it either...

took it into work today n a mates gonna cut out the rotten tube n fabricate a new one, so looking forward to that

but it won't be done quick as we can only fettle it when the boss is out!!!!