GT250X7

[SOman]

Finally faced up to reality and moved on my GT250A restoration project - haven't got the time, space or, these days, the energy to see it through, so, on to Ebay and off to another garage to add to the new owners list of projects. As consolation, I tracked down another 250 - this one running - a 78 GT250 X7, which, the owner assured me had been totally rebuilt 400 miles previously! Bike arrives - looks good, take it down for inspection pre-registration.....no front brake! - fork oil spewing out of the RH leg all over the brake caliper! Into the workshop - totally knackered, spongy fork seal (- Rebuilt front forks, including new fork seals......!)
Now I notice she's spewing out rather more smoke from the RH cylinder than the left - lots of smoke, in fact - as much as my S2 Kawasaki used to in 1972!
(- New big end bearings and seals Crank split and repressed.
- New Conrods and little end bearings.
- New half size over Pistons & rings and rebore.
- New full gasket set.)
Hopefully, it's just a badly adjusted autolube pump, not a dodgy crank seal...I suppose get it registered and take it for a bit of a run and see whats what. Hopefully, only minor woes to be sorted.
Ebay, eh - don't you love it.
Anyway - here's "Little Blue" (Big Blue is a Yamaha XJR1300)

[Craig380]

Wow, she looks REALLY nice. The good news is, all the important cosmetic bits are intact, like the tank, side panels, stock silencers, airbox and front mudguard. Over here in the UK, those parts are pure unobtainium. About 18 months back a pair of NOS silencers sold for 700 UK pounds.

X7s were wildly popular over here, even after Yamaha launched the 250LC, because they were several hundred pounds cheaper and not THAT much slower. Also much easier to tune ... which most owners did. Badly. They threw away the airboxes and fitted K&Ns (causing repeated seizures). They fitted Micron chambers and junked the stock silencers, or crashed a lot ... which is why you can't get stock exhausts or airboxes.

The good news is, they are such a simple motor to work on and spares are plentiful. If she starts well from cold the crank seals are probably OK. The smoking is likely to be one of two things:

1. Oil pump setting. Suzuki dramatically simplified the oiling system on the X7 and its little brother, the 200cc X5. Unlike previous GTs which had separate oil feeds from the pump to the crank bearings AND to the cylinder, the X7 just had one feed to the inlet tract for each cylinder. This mimics the Yamaha / Kawasaki approach. The pump is behind the gearbox sprocket cover and owners rarely adjusted it, so it's probably set on the rich side.

2. Exhausts clogged with crud. X7s were VERY prone to this, and it kills their performance in no time while making them smoke like a chimney. The good news is, the exhausts are two-piece making them easy to remove. Pull them off, remove the baffles, then poke a stick up the exhausts, give them a caustic soda enema, beat them with a rubber mallet, etc to dislodge all the crap. The problem is in the exhaust itself, not the baffles which usually just get oily.

I would suggest checking the oil pump setting first, then take her for a spin. If she's healthy, she should run sweetly up to 5,000rpm, then feel a bit edgy and unsettled for 500rpm, then above that the exhaust note gets a hard edge and the bike should GO. If it doesn't do that, clean the silencers

[Coyote]

Wow indeed. I never saw one of those. Suzuki's 2-stroke endeavor ended in 77 for the US. New emission laws and mandates, 4-trokes dominating the market, recovering from the RE5 failure and other factors ended the era. Yamaha made it through 79, exiting with the RD400 Daytona.
The odd thing is you could still get 2 stroke dirt bikes by the truckload. Any Jap brand you wanted, though Honda never played with 2 strokes very long. I did see a Honda 200 2 stroke twin ant the one of the vintage meets here.. Owned by and ridden by a female!.
Anyway, that is a slick bike. Has heavy Yamaha over tones to me. In my book that's not a bad thing. And Suzuki FINALLY got away from those ugly seams on the pipes That factor alone made the Yamaha more appealing to me back then. That coupled with their simplified oiling system -------- no brainer.

[SOman]

Hopefully It'll be registered next week so I can (legally) get out on the road and have a tootle. All the tinwork seems to be in good order - I'll play with the oil pump first, then check the mufflers if that doesnt work. I may check the muffers anyway - cleaning them out is often a thing that is missed/forgotten about/left to blind chance.
The 2 bolts on the front mudguard are a hangover from the days, bikes in Aus. had to have a front number plate. I don't know when that was dumped - I've only been here 9 yrs - but is a tell tale the bike was reg. new in Aus.

[joolstacho]

Heehee, those front numberplates, bacon-slicers we used to call 'em! (pedestrian gashers)- My GT500 ('77) has those bolts holes
And even my Velocette has them!!!

[Craig380]

In case you need them, here's links to the parts manual and Haynes workshop manual: http://www.suzuki-gt.co.uk/Reference%20Library.htm" onclick="window.open(this.href);return false;