Help Yamaha SRX250 oil cooler addition

As a new member I do realize this may be a bit of a "necro-post" reviving a yr old thread, but seems pertinent to keep the info in one thread.....I am a member of a facebook group for the TW200 & also own a xt225 so have been following the oil coolers for a while. While the original designer of that oil cooler (Lizardbreath on the forums there) has sadly passed away, another member has since picked up the torch and has carried it on ! He still currently offers the TW200/XT225 oil cooler kit ! ($170/shipped in USA)
It may take a few months till i am able to disable both my SRX250 & one of my 225cc bikes to compare housings, but i am contemplating getting a cooler for my XT225 & Perhaps also my SRX250 someday if it ends up being a bike i rude alot next summer. I am a bit skeptical as to whether they would devote the time to making an adapter for our SRX engines as they were quite rare here & that really only leaves the long discontinued XT350 model owners (& us srx guys) as a potential market, but maybe its just a few clicks in CNC program to plot the changes ( i'm no machinist so may be vastlyunderestimating the difficulty too so just in case it helps, heres a screenshot of the shop currently sellung TW200/XT225 oilcooler kits

 

I have no issues at all you reviving an old thread , especially when it comes to tech information that will help a lot of other's on this forum.
I have a O.E oil cooler kit that I'll never fit at this stage anyway , but knowing I have one if needed is a bonus.
I never liked the idea of the radiator in front of the head , but what do I know.
I've wanted to use a side mount oil radiator , but the cost of a new one when I was looking on the web was down right crazy.
The price listed for the aftermarket cooler kit is cheap enough , but no doubt the freight will bump the price up a tad.
But if you want a certain part(s) for your bike , what the freight is you can't do much about it , I know all too well.
Anyway , welcome to the forum.

 

The guy that sells the TW/Xt oil adapters will also sell just the adapter itself at a reduced rate so one can source their own cooler & fittings. I know it doesn't help us much being a different engine setup, but there a loads of "frugal" cooler/radiator options on aliexpress. Its a matter of getting an oil housing with ports. I can TIG weld bungs onto a stock housing & then tap them for fittings, but doesnt really help others much. Not sure i plan to run my SRX hot or at high revs for long, but being a rarer engine it would be nice to take so.e precaution to keep the oil from going thin. I will try contacting the machinist & see if he has ambition to make a 2nd housing design

 

Had to weld some rock damage on my XT225 case & for cast aluminum that has held oil it actually welded decent (Some cast engine stuff is a nightmare of porosity & contamination)
From the pic you posted (awesome you have a pic to work off, thanks !) It looks like the bung on the right is just some welding and a tap away from working, but like you said, maybe not so straight forward with that bung on the left side, has me wondering where it goes ? Appears it has a recess for an o-ring ? And lines up to a passage in the block ? When i get around to putting fresh oil & filter that isn't a 1/4 century old in my SRX I will get a better grasp of the layout hopefully.

 

Wow thats a great oil map. My 3 working brain cells still struggle to tell where that internal oil hole on the cover goes. But once i get mine off & change my oil i will reference this map for sure. I still think i can weld up a one off custom one fairly easy as the only precise machining needed would be getting the hole (circled in blue) drilled in the right spot once sufficient aluminum has been built up in there with weld (red drawings) to then surface back to flush with the rest of the cover & drill it all out (yellow).
Perhaps i am over simplifying it, but from what i see only one crucial spot to get precise, the blue/left hole location & its o-ring recess (do you know if that is an o-ring recess ?) The bungs can be "close enough" to use once hoses come into play, the hole on right just drains into the cover so location less critical there (in theory)
Now i am also noticing the cooler cover has the center section that looks like the letter C is also machined down...curious as to why ?

 

Ahh so that hole is an air bleed ? I just assumed it was a plug to seal that after drilling that passage into the center "c-section".
They say a picture is worth a thousand words, but in this case just a few of your words "should be oriented to the top" now have me confident I know exactly where to start looking inside the engine to see where the mystery hole leads to when i do my oil change.
It should be at the bottom. I will be looking to see if there is a hole in there & what it would take to seal/bypass it thru the cover, a cooler & back to the other hole that goes thru near our bleed screw. If it is copied to yamaha design what can go wrong ?
Earlier in this thread there is mention of thermostatic control.... did the yamaha factory kit have a temperature valve bypass ? or was it racing only option & thus no need to worry about running cold ? They pre-heat the tires & engines with electric blanket wraps & engine block heaters in many pro races so maybe we have different needs on the street ?

 

Do any of you guys know if yamaha put a thermostat control on the factory cooler setup ?
I ordered a stock oil cover to try modifying it for ports (using my TIG welder to build up material to machine) i can make the AN lines for it, & theres loads of cooler options for under $50. All that leaves is temperature control, did yamaha have a oil thermostat ?

 

If we need temp control, i think maybe I have found a cost effective INLINE thermostat made in the USA by Derale (hoping better quality than china stuff) that provides a bypass for the oil until it reaches 180F (just under 100C ? I think)

 

Yeah weird Australia didnt get coolers or belly pans. All i picture is madmax fairings on bikes going flat out thru the outback when i think australian moto, (not much media other than croc guys escapes your island to these parts !)
Not sure how hot other places that got the SRX get up to, maybe they sold well in Qatar ? I thought parts of Australia COOK in summer. I'm in the "cold" part of the states & we range from -30c up to +38c here. And highway speeds of 130kph for hours on end in 30c plus will thin oil in anything spinning high rpms to do it. My poor car needs 10w40 to not go thin in summer on the highway here.
Good to know a Tstat is not NEEDED. So getting the oil filter cover in hand & copying the factory ports is the only real hurdle, got a spare cover on its way now

 

Well i thought i stumbled on an oil cooler kit that was maybe right, even says yamaha 250 in title, but alas neither of the two (different LOL) measurements given for the cover bolt spacing matches our cover BUT SO CLOSE !!

https://m.aliexpress.us/item/225180...lgo_pvid=9137884c-a14f-4bee-92b4-074a3b624261
But the images may answer one of my questions at least. It appears there would be an internal o-ring in the cap to seal that one galley hole. (On this cap its oval, ours is circular) which would explain the recess around that hole in the factory cooler cap from the images Andych provided

 

Since your a Mad Max / bike enthusiast , here's a picture for you to drool over.



Regarding Goose's Z1000 , he hasn't have a oil cooler fitted , and look how he rode his bike out .
What great bike footage of when Goose was giving the bike a flogging out on the plan's , rev baby rev .

 

Ahh its THE BIKE ! Poor ole Goose needed a full body cooler in the end
Its too late now to save me from falling down this cooler quagmire, i got a spare cap on the way & an itchy TIG finger ready to add some metal for ports
Ironically (or hypocritically LOL) I was just telling a guy in the french alps over on the TW200 forum theres a good chance he doesn't need a cooler. But included the caveat that if hes often running max rpm, lugging bike up steep Alps in thin air, or working it hard off road going slow, its an "option". I encouraged him to instead get a head & or oil temp guage, that way he can verify its even needed ( i also have a temp sensor setup on its way from china already, will be able to scientifically show if a cooler is even needed (for my personal riding style & area) & hopefully, if i can make a functioning cap with ports can then show its real world affect on temps vs stock
I am convinced i can make a cooler for my SRX for well under $100, you guys will see the progress here ( or lack thereof if I fail, or give in & say not that necessary) i will wait to see how modifying the $8 cap goes before dumping any more $$ on the cooler & making hoses. Looks like i can also buy weld on AN fittings for under $10 vs. needing to drill & tap taper pipe threads, or attempting to get a perfect fit for banjo fittings. So I will be in it under $20 max before i know if its possible, to make this cap, or just lost time.