2 Strokes Down Under

Its the same for all models, per 200 strokes, but like I said strokes per minute for different bikes vary greatly. Its the speed at which each pump is driven that gives you the difference.
The only difference between a 250lc and a 350lc pump is the gear inside. The 350 pump delivers 30% extra in a given time, but the same per 200 strokes.

When someone sends me a pump I ask them to tell me what bike it’s for. That's because many 350lc’s have a 250 pump fitted. Many things can get swapped around in 30 plus years by people thinking that similar looking parts are the same. A guy from Aus wanted a 350 pump off me for his bike and I said I would do an exchange. When his pump arrived it was a 250 pump, and his worm was also 250 as the gear in the pump was undamaged. Unfortunately the big silver bird was on finals into Perth at the time, but I managed to get hold of the guy and tell him not to fit the pump! We sorted it out though. Much of my time is taken up with logistics like this to make sure people have the correct parts.

Ta, Arrow, I do know what you mean with the mix 'n' match RD/RZ stuff over the years..

What I was getting at was though, is there a chart published by Yamaha like this Kawasaki data : (see below)
( look down column for oil pump specs)

http://www.kawtriple.com/mraxl/modelspecs.html

& which also gives an actual expectation of specified oil volume delivery, over time, per rpm setting?

Or have you done suchlike output testing - yourself?

The Yamaha specs for the twin cylinder bikes are;
0.5~0.6 cc on minimum stroke and 5.1~5.7 cc on maximum stroke. This is for 200 strokes.
I tested many early build pumps and conducted my own work to find out what made the output less. There are nine different things which affect this. If you have to remove one or all of the defects the pump returns to a 'new' state, after this testing is no longer required. I doubt they were tested individually in the factory.

I found a cheap r5 pump. I will see how it installs. Would it be the same as my ds7? Cause technically the 350 won't need more oil. It could be a 50cc and still have the same ratio? I have no clue.

bosslock wrote:I found a cheap r5 pump. I will see how it installs. Would it be the same as my ds7? Cause technically the 350 won't need more oil. It could be a 50cc and still have the same ratio? I have no clue.

It won't fit! The gear inside the pump is different. You need the r5 worm drive to go with the r5 pump.

This course thread is what your referring too? So that is what I'll need to Replace in order to to make r5 oil pump work on a ds7?

The r5 Pump and ds7 Pump seem identical. Perhaps the worm has a smaller thread thus spinning the cogs on the pump to get a higher ratio of oil?

bosslock wrote:The r5 Pump and ds7 Pump seem identical. Perhaps the worm has a smaller thread thus spinning the cogs on the pump to get a higher ratio of oil?

I have already said this - a few times! Impossible to id that worm from your photo, sorry.

Very cool to hear your input on this subject Arrow

Here's the ds7 worm. How Does it remove?

Ooh, clear pipe! You'll get in trouble! ;-)

Could be a breather / overflow..

P.S. Arrow rocks [emoji106]

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Yeah, hope so.. it seems like we aint been too much actual use for the OP so far..

That clear pipe/air bubbles thing just makes no sense what so ever. I do not buy into that in the slightest.
If it lets air in, the oil would also leak out. You would never be able to use the clear hose for anything useful if it were true.

its my oil feed. the photo is of my oil gear drive shaft/worm