GT250 Fun and Games

Here you can write about your restoration highs and lows and hopefully final success
Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Special day - on leave and everyone out of the house!!!!!
Time to tinker in the shed.

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There is a oil dam under the bearing on one end and a seal on the other that prevents me from getting the knife edges under the bearing.

Had a scrap of 6061 25x60mm left over form another job.

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Milled flat and bolted them together to make a split pair.

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Machined to a 64.8mm (0.20 interference) with a lip in the inside to pick up the bearing above the oil dam.

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On the primary gear end bearing, as the puller was flipped over and the lip wasn't in use and it allowed the bearing to slip in the puller. I threw one side of the puller in the mill and machined off about 1mm on the bolt up faces to provide a bit more crush....worked a treat!


Now just have to make a few more tools to get the rest or it apart!

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Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Public holiday here so not much going on - didn't want to compete with the crowds at every slightly public place today so locked my self in the shed for the arvo - little Miss 4 was helping me so everything took that little bit longer but well worth it so that she may one day appreciate all the old bikes that Dad will leave to her!

Was going to get all pedantic and machine up a plate to hold the crank webs but didn't have any material and noting open due to the public holiday - thought I would give it a crack with a some offcuts of 6mm angle. It actually did it fairly easy - I don't have the pressure gauge fitted to the hydraulic press but it didn't take a silly amount of effort to press it apart. The bearing tool that I had made was again used for the center bearings - making that was time well spent!

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Crank apart and all cleaned up - the only parts that I couldn't get from Suzuki Australia was the conrods - have the ones that Cruzinimage sent me in that package with the incorrect pins and bearings - will use them with Suzuki small and bigend bearings.

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On the primary gear end seal there is some damage to the seal face - SKF makes a speedie sleeve that size, will have a think about that one - I can still throw the rest of the crank together in the meantime

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Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Things moving along nicely now that I have some parts - crank back together and pressed.

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Set the beg-end side clearance at 0.4mm. Can't find any information at what the factory clearance so if any one has the specifications I would be grateful if you could post them (closest that I could find was.......... T200 is 0.185--0.575mm and the T20 is 0.14--0.445mm)

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I bought a $50 induction form Kmart - told the Mrs it was so we could have Korean BBQ's at home - she saw through my lies when she walked in the shed to see me heating bearings on it.
Using a cheap thermocouple, heated the bearings to 80 Deg C - they slipped straight on!

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Bit of work with a large copper hammer has the crank runout less than 0.05mm.

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Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Rolling on to the wheels :ricky

The new rims supplied from Suzuki have a sticker on them "Made in Thailand" but are still stamped RK EXCEL. I've laced plenty of aluminium dirt bike rims over the years but never a steel rim.
I'm not sure if it was just poorly made rims or the fact that they are steel but I had a bugger if a time tuning the wheels - it took an extra couple of stubbies :drinkbut ended up getting them all below 0.2mm in each axis.

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NICE AND SHINY!!!!!
Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Supercheap had a sale on the other day - picked up a smallish sandblasting cabinet for $190.

Filled it with 0.85mm Crushed Glass - works well on steel, bit more aggressive than I had wanted but will give a good etch for paint to stick.
Was thinking about trying walnut shell down the track for alloy and softer materials.

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Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

For the 74 GT250L that I am currently riding am having nothing but trouble with the front brakes squealing. Have cleaned everything, tried different pads, scuffed up the disc - even tried another 2nd hand disc that I had.

In desperation I decided to get the disc ground.

Tried a few different brake places and none of there machines would take the Suzuki disc. Found one friendly workshop that let me measure up their machine so that I could turn up an arbor.

http://www.a1brakes.com.au/

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Even tested the new sand blaster on the hub. Like new!

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He had a bit of trouble with the disc chattering but the finish should be OK - and at least I now know its flat and true! When I fix the other issues on the bike I will report on the success.
Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Circumstances are forcing me into a change of direction for this project.

My GT250L 1974 bike that I’ve been riding around looks like it’s done a crank seal.

Some time ago, was walking through the shed and noticed the smell of petrol, was in a rush so quickly forgot about it. A few days later I was cleaning up to go back to work (go to sea for 4 weeks at a time) and found petrol dripping from the exhaust.

DAM – I forgot to turn off the petcock!

Early GT250’s don’t have an overflow on the carburetors – fills the pots when the needle and seat leak. Short of time I pulled the plugs, slowly turned it over on the kick starter, blew it out with compressed air and squirted some oil down the bore. Got home the other week and fired it up.

Bit of smoke out the left pipe…………….”it will clear when it gets hot” I said to myself.

Rode to the local shops – still plenty of smoke from the left pipe – white smoke!

Had another grand thought – “take it out on the highway and get it properly hot – that will clear the exhaust!”

Well……….……there isn’t an exit for about 5km’s. I attempted to disappear inside my helmet from embarrassment due to the now epic smoke trail that followed me……..and then I had to do it again for another 5km’s to get home.

I suspect that the residual petrol that was sitting in the crank for the month damaged the crank seal. The center crank bearing is lubricated from the gearbox, oil level in the gearbox dropped on the small but hazy test run.

So with the rego due and the fact that I was never really happy with the restoration that was done by the previous owner, it is now parked.

So the Suzuki GT250B 1976 that I’ve been playing is now going to be a nut and bolt restoration to appease the rivet counters and the GT250L 1974 will be the Café Racer.
Another contributing factor in this decision is that as ADR’s (Australian Design Rules) didn’t come into affect on motorcycles until 1975, so there might afford a few more liberties 74 that I couldn’t on the 76.

So the café project will take a little longer than originally intended – will do the resto first.
Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

So with the demise of the road going bike and this now turning into a two bike resto/Cake project, I didn't want have my bike lift permanently filled up with 70's 2 Strokes, so an alternate work bench is needed - getting to old to be working off the floor.

Left over from some house reno's (new stairs and landing) I had a length of 75x75x4mm RHS. For a bike work bench it is absolute overkill but I can't see myself having another use for it in the foreseeable future - best use it rather than constantly tripping over it.

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Bunnings (local hardware warehouse for those not in Australia) had sheets of 2150x600x30mm Soft wood pine ply for $65, add some Heavy duty 100mm Casters and 20mm leveling feet from eBay, I will be all finished for under $200.

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Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

New work bench finished - completely over-engineered but happy with the result!

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Even Little Miss approves!
Damian74
Posts: 45
Joined: Thu Jan 02, 2020 4:12 pm

Re: GT250 Fun and Games

Post by Damian74 »

Fork legs back form Rad Hard Chroming, won't say that it was cheap at $420 AUD (straighten and rechrome) but perfect job.
In comparison the new pattern fork legs that I bought for by GT250 74L were about the same after shipping - in chatting with the bloke at Rad, his reply was that his chrome will be thicker and last longer - as I can't see either bike doing 1000's and 1000's of kms and definitely not parked in the weather so I don't think it really matters.

So that took me back to my favourite job - polishing - MORE MESS!!!!!!

I thought that I would try Walnut Shells in my blast cabinet - didn't work so well continually blocking the syphon tube - tried different air pressures and nozzle sizes but nothing seemed to work. Looking on line at different sites and was thinking of fitting a metering valve in place of the syphon tube gun.......so for the interim I used glass beads. As a prep to polishing it took a lot of the hard work out - removed the factory lacquer and cleaned all the impossible corners.

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