GPz305 project bike(s) *with added FAIL!*

[stinkwheel]

It was getting dark by then so I went inside and TOTALLY stripped the carbs down to their componant parts, cleaned them in the ultrasonic bath, reassembled and re-greased the outer pivots.
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image043.jpg

Stuck the battery on charge overnight.

Next morning I went down and cranked it over a lot to get the oil going round. Fitted the exhausts using the old gaskets, I have new ones but they can wait until it is ready for the road.

The bit that took longest was fitting the throttle cables, they are having a laugh with those things! The nipples are right in the middle and have to be turned totally back on themselves to slot in. Then the combination of push-pull means there is barely enogh slack to get the the cable outers in their slots. Took me a good 45 minutes!.

Does it spark? Does it hell. The coil connectors are all corroded to hell and they have the most tenuous of frame earths. Connectors duly replaced and I hard-wired the coils back to a good frame earth point under the saddle.
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image040.jpg

Spark miraculously returns

So, Carbs on, fresh fuel in, press the button and... Fires up and runs.

It's bogging slightly in the midrange but it needs the airbox connecting.

I'm patting myself on the back when I notice smoke coming off the left exhaust and oil dripping on the floor. Rats cocks!

It's pissing oil round the head gasket at the front left corner. Nothing for it but to strip it back to the barrels again.

This is highly annoying because I KNOW both the head and barrells are level, I lapped them on glass, I used a new head gasket and I did all the torquing exactly by the book.

Ok, this time I've done it the traditional way and cut out a gasket from copper sheeting (not too time consuming on an air cooled twin). Annealed it on the gas cooker and coated it in a very sparse layer of well thinned red hylomar which was allowed to dry (thins to almost liquid with meths).

Reassembly this time was much more rewarding. No funny noises, no oil leaks and it will idle at under 1,000rpm implying I must have done a neat job of filing the same amount off both pistons.

So, tonight I need to re-fit the airbox rubbers and the freshly cleaned and oiled air filters then I can make a start on the chassis.
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image041.jpg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Thom]

Mister Mister, fix my gs?


____________________
Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

[stinkwheel]

[quacker_boy]

I hope by the time I'm your age I know as much as you do, if not before. That's a serious amount of knowledge, I feel so useless now

Keep it up, I'm enjoying this
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wizzzard wrote: Imagine God just stopping by, tidying your front room up and then quietly letting himself out again. Statisticly more likely to happen than Korn being on here.

[stinkwheel]

Well proof of the pudding. Lashed it all back together enough to be able to just about ride it. Tyres are soft, front suspension is sagging badly and the brakes are barely functional but it'll go.

And bugger me does it go! Pulled 85mph out of its arse without even trying. I didn't dare go any faster with the state of the rolling chassis but it would have done. This is a bike that'll do the ton

Tonight I stripped the forks off and dismantled them because it'll need new stanchions.

I just drilled the bastard allen heads out of the bottom. If they can't make their fittings reachable with normal tools, don't expect me to treat them with any degree of respect. Drilling the heads off was by far the quickest and most effective way of dismantling the forks.

There ought to follow a link to a short and crappy video clip of it being started and revving a bit:
https://s48.photobucket.com/albums/f216/stinkwheel/305/?action=view¤t=Video000.flv
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[mr jamez]

For the (often badly designed) fork bottoms I use a normal hexagon key with the same size socket on the right angled end, attach a extension bar and bingo.

Its interesting to see what you can get away with on the more basic bike engines, filed down pistons
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NSR 125F > BROS 400 > NC30 > BROS 400 > Trumpet S4 > '97 VFR 750

[stinkwheel]

[stinkwheel]

[Gazdaman]

A well written email! I had to write a similar one recently regarding my GS. I wasn't unhappy with the bike, but it had lots of things wrong with it. So I needed to let the guy know I was unhappy but I wasn't looking for money back or to return the bike.

Difficult.

Would stud extractors not work?

Gaz

[stinkwheel]

[stinkwheel]

Well. I've put the forks into my mates engineering shop to get him to drill the bolts out. I was making an arse of it on account of not being able to hold them still enough.

Today.

Checked it was charging the battery. Yes. Dropped the oil, mucky but no bits of metal. WD40-ed the horn assembly, Fookin loud twin horns!

Arse out:
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image055.jpg

Remove, clean and grease brake pivot, tension adjusters, unitrak bushes, shock and dog-bones.

All needed doing as the original grease had all dried up or vanished.
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image057.jpg

The only bit with any serious corrosion was the swingarm. Probably because there is no chain lube fling to protect it. Duly stripped, gone medievil on with angle grinder mounted wire brush and given several coats of zinc primer.
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image056.jpg

Tomorrow. Top coat. Probably in black bitumen rather than the original silver on account of how the bitumen paint will be better for stopping rust.

Might also renew the brake fluid. I've been feeding the bleed nipples penetrating oil for a few days now.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[MarJay]

There's something quite cool about the twinshocks wheels. They just have a soupçon of retro cool. If you can get one working and reliable GPz 305 out of that lot I will be very impressed!

[quacker_boy]

[stinkwheel]

Booked in for an MOT tomorrow.

Fixed the constantly on neutral light (my fault, trapped the wire under a casing).

Balanced the carbs. Just goes to show that static balancing is often close enough, I was only half a turn out on the balancer screw having eyeballed the butterfly positions.

Note highly expensive auxillary fuel tank and fancy tube clamps to damp down the needles.

https://i48.photobucket.com/albums/f216/stinkwheel/305/Image061.jpg
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image062.jpg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[ish765]

Going good stinkwheel.

I have a confession.
This used to be my dream bike when I was 20. I eyed it up as the perfect touring/do anything bike. No need for any more power than this. I recall it's really good mpg also. 4 stoke, yea that’s my bike.
O shit it was expensive.
But I still used to look at it showroom thinking I could get it somehow. Hp maybe? What a dreamer.

[stinkwheel]

Been for and passed the MOT. Advisory that the brakes are binding slightly (sticky pins) and one disc appears to be slightly warped (almost certainly corrosion on the wheel hub).

Usual vertical play in the unitrak bushes "They're all like that mister.". Thankfully, my MOT guy knows this and didn't make me spend another £45 on new bushes that will be just as loose as the ones that are in there already.

Rode it a total of 150 miles today. It's now in York waiting for the GF to finish work. Sat at a steady 80mph most of the way with no dramas. Push it to 90 and it starts smoking like a chimney, 100 and it's a proper smokescreen. The bore is a bit worn though, this would appear to be a symptom. Also has a small oil leak round a couple of the alternator casing screw heads but I did re-use some pretty ropey looking o-rings under them so easily fixed.

There is a fair bit of clattering/rattling going on in the top end. I suspect there may be a little piston slap and a fair bit of tappet noise. I'll re-adjust the tappets now it's all settled. I'll also re-fire the camchain tensioner just in case (you remove it, compress the spring, hold it in place with a bolt, re-attach it then undo the bolt. The tensioner plunger flys out and presses on the blade).

Mind you, a lot of it may simply be due to me not being used to riding an air-cooled 4-stroke, they are bound to be noisier than a liquid cooled bike.

Not sure the battery is holding a charge properly so I'll nip over to Halfrauds tomorrow for a sealed one and some new sparkplugs because I don't know how old the current ones are.

It can stay as it is for the moment with regard to the bore. She doesn't need to be going over 85mph yet anyway and I'll show her how to keep an eye on the oil levels. Meantime, I'll have some spare barrels bored out to take Z650 pistons (have both) and I'll convert it to a 325 once she's used to riding it as is.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[stinkwheel]

Made it back from York, 2-up with luggage and topping out at about 75mph.

Seems to have lost some of its thirst for oil now, maybe just the bore and valve stems settling from a long period of disuse.

Did a total of 350 miles over the weekend.

After a minor debacle getting a new battery (more a reflection on motorbike dealers than the bike), the girlfriend is now away off up to the Highlands on it.

She's ridden it another 180 miles today, complete with camping gear. She reports hitting 100mph on it a couple of times.

She also reports the steering weaves a bit at speed. Closer inspection reveals that the Haynes book of lies lists the rear tyre pressure as 10psi below what it should be.

Much less clattering after I adjusted the tappets.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[MarJay]

[stinkwheel]

Well, I'm preparing myself for the "I told you so" brigade.

To anyone considering filing a semi-circle out of their piston skirt. Don't.

850 miles after the MOT, the girlfriend has been to Glencoe on it hillwalking and is on her way down the M74 when it stops abruptly. She took my advice on what to do after hearing a funny noise or loss of power and pulled in the clutch immediately.

Good job she did because the conrod had just made a bid for freedom through the front of the crankcase!

Crankcase
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image073.jpg

Barrel
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image074.jpg

Piston
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image075.jpg

The rest of the piston
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image076.jpg

The most bent conrod in the world ever?
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image077.jpg
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image078.jpg
https://i48.photobucket.com/albums/f216/stinkwheel/305/Image079.jpg

On the plus side, the actual crank itself is ok. That means I can get my mate to press it apart and fit the intact conrod off my other knackered crank. I have a spare set of casings, I know what I'm doing with the engine now and I got a set of pistons and barrels off ebay this morning.

Cylinder head is intact, the piston touched the valves so they'll need checking but I have two spares if they are bent.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Kickstart]

Hi

Can't really see in the pic, but looks possibly like a crack has started in the area where you removed some metal and then spread to the gudgeon pin hole. Might have got away with it with a smoother finish to the removed secton (not that I recommend you try it again).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[MarJay]

Hey Stinkwheel,

I did think at the time when I saw your filed up piston:

[stinkwheel]

The whole piston thing was basically kawasaki wanting £80 EACH for piston kits.

Never in a month of sundays is a piston kit worth that for this bike. That's £160 for a pair plus more for the rebore which it would need if I was spending that much on pistons.

So, the pistons were filed because I would rather throw the whole thing in a skip than drop the fat end of £200 into a 16 year old engine with such dubious reliability.

Cheers for the offer of the FX. Kat has however decided she likes the GPz and my house is like FULL of bits for it.

I'm actually quite pleased in one way that this happened because I can junk a set of casings and assosciated crap thereby creating some space.

I'm SOO going down the metal merchants with a van load of scrap soon. I have way too many bits of fucked motorbike lying about the place "just in case".
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[chris-red]

That is pretty impressive

On a side note, I always got the impression Stinkwheel was how shall I put this, wasn't long from a free bus pass . How old are ya dude?
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Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[yandy_yay]

well i really liked reading that thread, shame that it kinda ended in a big FAIL but still i guess you would have never known if you had not have tried it, probably something i would have tried my self lucky ur GF pulled in the clutch could have been nasty on a motorway.

Scrap i tend to keep all sort of junk for that elusive just in case moment i bet there is stuff up my loft that hasn't seen daylight for like 20 years but i still can't throw it away.

best of luck getting it rebuilt again.
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past bikes: (20 years ago) cg-125 (wriiten off), C-50 (thrashed n' finnaly scrapped), CZ-125 (nicked - never recovered, insurance payout was more than i paid for it !!!)
Current bikes: GN 125(now sold), Divvy 600s.

[stinkwheel]