Suzuki 2 Strokes

Hello All,

I've been working on the oil lines of my '69 T350 - one of the check valves was seating intermittently, which occasionally caused it to pull air into the line.

Interestingly, unlike all other information I've found for T350's, I found that my bike was fitted with rebuildable check valves on the ends of the oil lines, like Kawasaki oil-lines of similar vintage. I thought that they may have been modified to accept the fittings from Kawasaki lines by a previous owner, but the banjos don't look exactly the same.



In fact, the only place that I have seen similar lines was on Old Japanese Bike's website, on his 1968 T500 project page (see "injector valve" photo here, https://www.oldjapanesebikes.com/1968_T500/page-2). Those line ends look like an exact match to what is on my bike. I guess it's possible that some models may have used this same rebuildable style through '69?

Anyway, I was able to replace the check ball and spring with parts being sold by "tv4fish" to rebuild oil lines on Kawasaki triples (https://www.ebay.com/itm/203520775805?h ... SwWuNgN4J0, or http://3cyl.com/mraxl/oillines/check_valves.htm). In case anyone is in the same situation, it appears that these parts are compatible between the bikes. I can't confirm the longevity of the new parts, or whether the oil flow is still appropriate with them, but they got me back on the road for now.

I have a 69 T500 project bike that has the rebuildable oil lines.
Have an original printed parts manual for the 69 T350 — part numbers are different than listed for later model years.

Suzuki didn’t necessarily make the transition to the later oil line design with the start of a new model year. Most likely switched when they ran out of the rebuildable lines.

The pump is a displacement type, so the pressure to operate the check valve isn’t that critical.
But the ball needs to be a similar diameter so that it seals when closed & allows flow when open.

Hey, thanks for the info jabcb. Yes, that makes sense that they would have carried on with those fittings in production until some switch-over to the later design. Admittedly I can see why they did it too, as the fully integrated part eliminated cutting a couple threads, and removed the crush-washer seal - must have been a bit cheaper.

And yeah, that's also a good point on the pump. With it being a positive-displacement type the flow rate wouldn't be affected by the opening pressure of the check valves would it? Just adds a little extra work for the engine to do if you up the spring strength.

For what it's worth the check balls from the kit sold by tv4fish were a perfect match to my original Suzuki ones - just under 0.125". So if someone else needs to service their lines I wouldn't hesitate to send them that way.

Regards,

Jim