Hi,  
I have a general question as I have learned more about 2 strokes.
First off,  I am a believer in running oil pumps and not removing them.   However, for those that do,  I have learned enough to have this general question.

While there may be more than two subtypes, I am concentrating my question on these two that I run across.
1) Oil injection that feeds into CARB or INTAKE port only.   -  These seem to mix with the gas and lube all the internals including piston, crank bearings .....   In tearing an engine apart (yamaha enduro in this case) ,  I have learned that there are holes (channels) that run down to the bearings.  THis allows oil/gas mixture to get to the bearings lubricating them.  In this case,  I can easily understand removing the oil pump and putting in a block off plate and running mixed gas.

The one I am having trouble with is the following:

2) In some bike systems,  the oil feed line splits into multiple hoses.  One hose goes to a port that feeds oil directly to the crankshaft end,  THrough a port in the crankshaft, oil is fed to the bearings.  Oil also continues down the crank and is fed to the main crankshaft rod bearing.   A second oil tube either goes directly to the carb/or intake, or on some bikes is directly fed and squirts oil to the cylinder walls.   

My question is,  In a system described in 2),  if you remove the oil pump and put a block off plate,  Are the crank and rod bearings lubricated sufficiently with mixed gas?  It does not seem like they would be lubricated sufficiently.  I Typically see this kind of a setup in multi cylinder 2 strokes on bikes and in snowmobiles.

Thanks in advance.  

John

From my experience you're pretty much comparing #1 = Suzuki vs #2 = everyone else. Yes, you're getting enough oil to the crank and rod bearings, in part because the  crank and main rod bearings are  rollers and if I remember right, the wrist is a needle bearing so those help alleviate the need for oil to be floating the bearings as oil typically does with plain bearings in a four stroke.

Suzuki didn't always split their lines either, I have a 2004 snowmobile with a Suzuki 900 twin engine and the oil line only goes to the carbs.

Thank you. Your answer helps alot. This question arose because I am looking at an old Suzuki which someone gave me with another bike purchase. DId not really want it, LOL. Anyway, playing around with it, after . 50+ years sitting, and it fired on gas/oil in spark plug holes after bugging out some electrical issues. amazing. Next step is to clean up and evaluate the oil injection, but I was wondering if I could run it on MIX without hurting anything

THanks

john

I'm no help but I recall very early TS Suzy's I think that had one line to the inlet & one to the left main with had an oil slinger disc inboard of the main against the crank with a locating piece into the crankpin. Oil fed to that left bearing got slung around & into the hollow crank pin hence out into the big end caged rollers. I broke one of this hollow pins once racing a 100cc doing twice the revs it was designed for. Hell did that vibrate as I grabbed the clutch haha. But I've got no answer. suzy had a good system so I'd leave alone if its working. Probably 20/1 mix & it'd get everywhere it needed too even if the rod isn't slotted. RH main will be lubed by the trans oil with an inboard seal so one less to worry about. I'm in NZ & we do all sorts of dodgy tricks down here lol. Talking for myself of course & not everyone.

You have to be careful...  some of the bikes with direct injection to crank/main bearing WILL fail prematurely if you remove the pump. 

Some have shields/baffle plates that can be removed to run premix successfully. 

For some like the old Puch 250 (that had "autolube" 10 years before Yamaha "invented it" ) , I've heard many reports that crank will fail prematurely without a pump...  which is a real PITA because the old Puch pumps were leaky when new and hard to find in good shape these days.  I don't think they have any seals but are located under the clutch cover so at least leakage ends up in trans...  supposed to run 50 weight two stroke oil which isn't easy to find these days. 

So it really depends on how they designed the engine oiling system...  studying manual pictures and diagrams might help if you don't plan on tearing it down. 

(I think a few of the Kawasaki's you have to be careful with too...  along with some Suzuki's)

Like RT325 said that Suzuki probably needs the pump for the crank bearing, only way to safely run it on premix is to split the case and drill holes so the oil can get to that main bearing.

All the TS/TC bikes from at least 70-80 were that way, my experience doesn't go beyond those years or models.

If the pump needs work give a shout, Suzuki doesn't list the seals for it but Kawasaki does and they used the same Mikuni oil pumps.

I'd love to know where to find those seals, or a cross-reference for kawasaki. I'm trying to get my old 76 ts185 Sierra to quit dripping 2stroke everywhere. It feels like theres slop in the axle of the oil pump and it seems to be losing oil at that point. Is there and o-ring in there? How do I replace? --took the nut, lock washer and spring off, but not sure how to remove the shaft/axle and inspect. "Slop" - It jiggles in and out, but no slop in the rotation.

Hopefully DarinM will see this and respond...

And here's a link for the pump from a 1976 Kawasaki 175...  not sure if it's the same but you might be able to tell.  www.partzilla.com/catalog/kawasaki/motor...76/kd175-a1/oil-pump

MarkT is spot on as usual, 92049-1294 did fit the oil pump on my 1972 TS185. It is tighter than the stock seal as it's an updated seal. I had to grease it and work the pump arm a lot to get it to "break in" and let the arm return with the stock spring. Worst case it makes the pump stick open so you'll foul plugs but not hurt the engine.

After replacing all the oil pump seals and o rings, shifter seal, and countershaft seals, a year later it started leaking oil again but nothing a little cardboard on the floor can't take care of. Unlike before, when it was losing a lot of two stroke oil, now it's not a noticeable amount when I check the injection tank, even after a month or two.

To replace it the pump must be removed from the machine and torn all the way down. It's not too hard, just a little puzzle in itself for how to get that shaft out, if I remember correctly a few things must be aligned in the right position (something is removed out the top of the oil pump?) and then the shaft comes right out the front.

I can't verify, but from a Suzuki group I'm in;

Rear Seal 8 x 14 x 4mm

Top Plate O-ring 12mm ID x 1mm thick

Control Shaft O-ring 6mm ID x 2mm thick

Bottom Plate O-ring 16mm ID x 1mm thick

Rear Drive Spigot O-ring10mm ID x 1.5mm thick