Starting bikes that have been sitting

[Gaff]

Hi all,

My father left me a number of bikes, a gt250, gt550, ts 185, Kawasaki Mach 3 and a Yamaha xs750. All have been garaged and covered with sheets since he purchased them over 25 years ago. All are in really good condition, are complete and appear largely original with low miles on the lot. After some advise as to what I should do before attempting to start any of them? To the best of my knowledge none have been run in the past 5-10 years.

I'm reasonably handy with tools and bike maintenance and do all my own maintenance on my own dirtbikes, but old Japanese classics may be a bit of a challenge.

Really keen to get these bikes going again and some of them back on the road. Is it as simple as draining the old fuel and kicking them in the guts to see what happens or should I be doing more?

Thanks

Gareth

[GT750Battleship]

Hi Gareth,I'm in Sydney,the two strokes will require some care before starting...after some years of "sitting" (much more than 2 years is a worry!!!) they run the risk of dried out crankshaft seals & condensation (rust) on the crankshaft !
That said...fresh fuel,two stroke oil,gearbox oil,clean plugs..they could still fire up..& run happily for years, before any motor problems occur...luck of the draw , so to speak.I'd take the plugs out & turn the motors over by hand to see how free everything is internally,even gearboxes can seize through lack of use.You could contact The Vintage Japanese Motor Cycle Club in your home State for advice & assistance,I'm sure they could recommend someone to come & have a look at your "Fleet" PS Welcome to the Forum !
Regards,
GT750Battleship.

[Suzukidave]

Wow .. your Dad did leave you with a nice collection .. an addition to whats been suggested already is the carbs are most likely going to need a cleaning out as the old gas evaporates out it leave behind a white powder that just clogs up everything .

[ConnerVT]

Much depends on how they were put away 25 years ago. Ideally, if you were to park a bike for 25 years, one would drain the gas tank and the carb bowls, perhaps fog the interior of the tank with light oil to reduce rusting, replace the transmission oil (and the crankcase oil in a 4-stroke), as a start. Gasoline tends to become a solid varnish after 25 years (sooner than that, actually).

So the first thing to do is inspect where you are. If the tanks are completely dry, perhaps the carbs are as well. With a flashlight, check the tank for anything that doesn't look like it should be there (rust, sludge, insects). If there is junk in there, you should thoroughly clean the fuel system, including pulling the carbs and disassembling them. Just spraying a carb cleaner through them probably won't help.

You will also need a fresh battery. You can start with one battery, and move it from bike to bike when you are ready to attempt starting them. Bikes of this vintage generally need a battery to run, and some use the battery as a voltage regulator. You'll blow bulbs without a battery installed. I'd also replace the spark plugs unless they look (nearly) brand new.

I don't know how much faith I put in 25 year old 2-stroke oil (though it probably isn't the worst thing to have). You probably don't need to change it for an initial/short startup (as it will be running on the oil in the lines/pump anyway). But I would drain and replace with new before doing any serious running time.

Good luck, and keep us updated as to how they respond to being summoned back awake after the long sleep.

[T350guy]

Because they have been sitting for so long oil may have leaked down into the crankcases.
On the GT's you can remove the SRIS valves and drain , on the kawi 3 you may have to leave the spark plugs loose.
This is just to avoid hydraulic lock on start up as a bent rod may occur.

[Craig380]

With the 2-strokes, as mentioned above the big risk is that the crank seals may have dried out or got stuck on the crank, which can tear the seals when you turn the motor over. If this happens, the engine WILL need a crank rebuild.

I have heard of people pulling the carbs off, mixing up a litre or so of 4:1 mix of petrol and pre-mix 2-stroke oil and pouring the brew down the inlet stub, and a little down the spark plug holes, then letting it sit for a couple of days to soften the seals. Then after a couple of days, leave the plugs out and turn the engine GENTLY by hand on the kickstart a few times, to see if everything moves smoothly.

If it does seem smooth, remove the exhaust headers and kick it over harder to purge the mix out of the exhaust etc, then button it all up and see if she'll start!

It's messy but could save a bottom-end stripdown ...