RZ/RD 350 & Misc. 2-Stroke Tech BBS

I pulled the oil pump off while I was waiting for the new water pump seal and a lot of 2 stroke oil came out. I had rebuilt the pump with all new seals but was wondering if the worm drive part of the pump should have oil in it? Any wisdom on this?

Arrow, is there supposed to be oil in the worm drive section of the pump? I rebuilt it while the bike was apart and checked the clearance and all was good but I pulled it since I'm replacing the water pump seal and a bunch of oil came out.

No problem with the o-ring I can see. Looks perfect- it was new and was no pinched. I had coated it with a little red grease before assembly. I'll use some Hylomar this time and make sure it is sealed! I'll also replace the pump shaft seal. On the crank seal issue... I pulled the clutch and drive ge...

I did... new oem Yamaha part. I'm about to pull the clutch cover off and let the rest of the goo drain out. I wonder if the o-ring got pinched. I've seen that happen before.

Well, the plot thickens, or thins like this oil. Pulled it in the shop and drained the oil so I could take off the clutch cover and this is what drained out. I assume the water pump seal is bad? I had just checked it when I rebuilt the oil pump and it was actually tight on the shaft when I spun it. ...

All new parts from Yamaha, no reproduction stuff. What spacer are you referring to? The one inside the clutch basket? If you have a part no on a diagram that would be great. I pulled up both the crank diagram and clutch and I'm not sure what you're referring to. But, this is a 4k mile motor that sho...

I lubed everything with 2 stroke oil as I was assembling it. I did not use any kind of grease on the seals, though. I think the manual says to use 2 stroke oil...
Can it be sucking oil in around the key on the shaft?

Well, I spoke too soon. I went for a longer ride and and came back and checked the oil level in the gearbox and it was down below the dipstick. Rt side exhaust was also quite a bit hotter than the left. So, apparently it is still sucking oil through the rt crank seal. But it was not excessively smok...

Just an update... took it out for a ride after bleeding the oil lines and it runs perfect with all the new seals and gaskets. Also rebuilt the oil pump since it was apart and I didn't really want to worry about it. Used the digital thermometer on the pipes to make sure both cylinders were synced goo...

Decided to take the oil pump apart and check everything and replace seals while the engine was apart. This is a 4K mile bike that had never been touched so I was surprised to see this when I took the oil nipple off to check the ball/spring. Must have been done at the factory. Apparently didn't affec...

You need new float needles and seats, at least. I'd take them apart and see what you actually have and make sure they are all adjusted properly, too.

Maybe not the original bowl on that carb? Is the other carb different? Mine are identical...

Engine is back in... I could see a definite difference on the inner lip of the rt seal compared to the new seal. I'm adjusting the oil pump and my manual pics are so grainy that I can tell what mark I'm supposed to line up the pointer with. Bottom pic is with the throttle closed and top is open. Can...

It made a ton of smoke for a while then just stopped- I assume when the oil level got below the crank seal. Then started getting hot, I assume, from sucking air. I'll pull the baffle from the pipe and look at the cat. You can see it easily from the end. I'll pull the pipe from the air injection and ...

Hopefully, with all new seals, case sealer, gaskets, etc the problem will be solved. Plugs looked fine but it really hadn't been ridden very far- maybe 10-15 miles. Cases cleaned up nicely but there was a lot of carbon around the seal and lots of oil in the case...