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Yeah, wont work unfortunately.

Thanks for confirming.

The rear sprocket bolt pattern is wider on a 400 compared to a 350, if that is what you're asking.

Thanks for clarifying. Yes that's what I am looking for.

I am looking to install a 15/37 sprocket set for my 75 Rd350. Will the US 1979 Daytona std 15/37 be a straight fit? I understand that that bikes had spoke/alloy wheels but not sure if the clutch hub dimensions are the same.

p.s.: The 350 has a 400 transmission installed which has a closer ratio 4/5/6.

TIA

32T is correct for a 350 pump. You're good

RD350 & R5 pumps are interchangeable (both "red")

Thanks so much for all the help 

I pride myself on collecting meaningless, minute and obscure info related to all things Yamaha.

a living encyclopedia!

Based on appearance, since it looks to be from an R5 that's correct, it would have the bush embedded in the housing since it's an 'early' pump.

The parts list also lists the same numbers for the R5 and 350 pumps - 360-13101

The reason I asked about the tooth count on your ring gear is because I wanted to make sure you truly have a 350 pump. Many pumps are listed on eBay and other places as "RD350 oil pump" when they in fact came from a RD250 or DS7 or CS5, etc. You should be OK because I see a red paint mark on your pulley. R5 and RD350 pumps are "Red" color code in the Yamaha parts world. However, just to be sure what you have, post a photo of your ring gear or list the tooth count. A 250 pump will not work properly for your RD350. Based on the red paint and the banjo bolts (as Mark mentioned) I'd guess you have an R5 pump. It will work if you verify the internals are correct.

32T; is that the correct one for the 350?

For oil distribution lines you'll need new 5mm oil feed hose Yamaha part # 90445-05M07-00 (1 package can do both sides), and 4 oil hose clips Yamaha part #
90468-02033-00. Economy has these parts. You won't need the banjo bolts on the old hoses. 1970 through 1972 250/350 twins used banjo bolts for oil feed, but 1973 and up switched to nozzles on the carbs.

Thanks. Would you recommend going with transparent tygon lines for fuel + oil or stick to oem?

thats a banjo bolt, and thats for an R5 or DS7

Oh! Looks like the connectors for the R5 are different. Are the oil pumps the same for the RD350 and the R5?

question: do you have your original oul pump?

No I don't. I bought one off eBay and trying to rebuild it.

What is the recommendation on the hoses and clips? This is what my pump came with. I don't know what is the circle shaped thing at the of the pipe for? I assume they are inlets to push oil to the carbs but I cannot find them in the parts catalogue.

[PIN, SPRING - Yamaha 91608-20010-00]

Yes there are 2 dowel pins in the distributor under the worm wheel gear. Each pin has a spring. Are you certain that the spring is not stuck down inside the bore? Sometimes this can occur after the pins are removed, the spring can get kind of 'glued' into its bore with old oil and varnish.

You need the following parts:

1) PIN, SPRING - Yamaha 91608-20010-00
Part is NLA from Yamaha so you'll need to source a NOS one or find one from a hardware supplier. Size is M2x10.
It's press-fit roll pin. I think the reason the one shown in the YT video is threaded is because he's likely working on a Rajdoot not a Yamaha. Vintage Yamahas do not use a threaded pin to retain the pulley.
https://www.ebay.com/sch/i.html?_nkw=yamaha++91608-20010&_sacat=0&_from=R40&_trksid=p4432023.m570.l1313

2) SPRING, COMPRESSION - Yamaha 90501-02016-00
It is NLA from Yamaha so you'll need to source an NOS one or get it from Economy Cycle or HVC
https://www.ebay.com/itm/133088410324
https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/engine-related/oil-pump/oil-pump-worm-gear-pins/

When reassembling, make sure you have the worm wheel gear oriented in the correct direction. Otherwise the clutching function will not work for the manual priming wheel and the worm drive from the engine will tear apart the inside of the pump. I ran into this a couple years ago when I acquired an RD350 that was worked on by a "factory trained shop with 25 years of experience". They obviously didn't know what they were doing because they rebuilt the pump backwards. I was fortunate that Mark (m in sc) had a spare worm gear for me so I was able to rebuild it correctly.

Out of curiosity, how many teeth are on your worm wheel?

Also if you have a newer pump you'll need the worm drive bushing on the end of the shaft.
WASHER PLATE - Yamaha 90201-08624-00
These are still available from Yamaha, and Economy stocks them as well.
If you look down into the well where the shaft goes and you see a pressed-in bushing like this, then the part is not needed.

This is great info! Thank you!!!

If I may ask, how did you manage to find part numbers for items that are not listed in the parts catalogue?

Looking into the pump, the bushing is installed. So I don't need the washer plate. Thank you for this info.

Thanks for all the info.

1. If I understood correctly, I need 2 of the tiny springs? I can look up economy/hvc for it.
2. Can the pump be operated without the roll pin? This disassembly video shows that it is a screw type pin?

https://youtu.be/rcF8Ztn5zMY?t=147


From this exploded picture of the autolube from HVC, I think I need

1. Adjust Pulley Guide
2. Pin Return Spring

https://hvccycle.net/oil-injection-pin-return-spring-hvc200103-4/#gallery-2

Transmission Ratios
TZ250     RD400   RD250/350
.81            .888         .785
.87            .961         .888
.96            1.083       1.040
1.13          1.318       1.318
1.42          1.778       1.778
1.93          2.571       2.571

This is great info on the history. Forgive me if this was posted somewhere and I missed it; AFAIK the UK RD350B 1975 later models (521) came with the 400 Trans ratios.

source: https://www.aircooledrdclub.com/manuals/350AB.pdf

Hi,

Great forum and a wealth of knowledge and experience on 2 strokes here. Thanks for allowing me to post.

I am trying rebuild an oil pump that I got for my RD350. This is my first attempt, so please go easy on me.  After disassembling and cleaning up the pump and parts, during assembly I ran into a few questions.

1. I see that I have only one tiny spring for the 2 pins that go into either side of the gear. I assume I would need one spring for each of the pin. Is this correct? If so any idea where I can source one?



2. The pump also appears to be missing a pin (inserting picture of a pump found from eBay with the pin). I assume I need it. Where can I source this one from? Cannot find it on any parts list so don't know what to look or ask for?



3. I see this cover (402-13146-00) on some pumps listed for sale but mine didn't come with one. Do I need one? What is its purpose? And why do the pumps have it but I cannot find it on an exploded diagram on partzilla or elsewhere?



TIA
cheers