cooling system

[Boneswig]

I remember from my first XS that she used to run hot in traffic. Also doing memorial runs I battled with heating problems. I designed some air tubes I will be fitting to the front to deflect airflow to the head, but was wondering that if I could connect an oilcooler to her, where would I draw feed from and where would I fit the return? If I can fit some form of oilcooler to the motor, I can cool her down with an electric fan running on a temperature switch and combined with the airtubes I should be ok in traffic and memorial runs. Any help or advice or input would help.

[natemoen]

They make oil coolers for the xs11. There is a plate that goes between the oil filter cup and the engine that the cooler hoses go to.

[madmax-im]

I have an oil cooler on mine...dont ask me about it though...it was installed by the previous owner...

[BA80]

The oil cooler helps a little in slow traffic. Not many other choices. I run one on mine.

TC has adapters for a spin on filter that have ports for the oil cooler lines also. I recommend going that way if you install an oil cooler.

[Boneswig]

If I fit a highspeed fan to blow air through the head (the fins going thru to the sparkplug, would it work? I'm just scared ill have to much cold at the topend and damaging the head. I can build ducks to those fins, in theory, heat goes up, so I I cool the top part of the head, it will cool the oil down a bit as it goes back down.

[MPittma100]

Cooling

When you say it runs hot, how are you determining this? Nothing other than an oil cooler has ever been added to these bikes and Yamaha only did that one year in 1981 here.

The electrical system will not handle a fan. It will be too parasitic. You would have to have a second battery separated from the first. Running a richer fuel mixture will run let the engine run cooler compared to the normal lean setup.

[Boneswig]

Aaaaaah! Ok so I just need to run richer to keep the motor cooler. We'll with my first xs I could smell the heat (hard to explain but it's a different smell). I still need to do the carbs so will try them standard and if I feel she is running hot in traffic, I will make her a bit richer and work my way up from there. Thanks, been great help. The fan I had in mind is a 12v 0.7Amp highspeed with speed control. It's about 4 X 4 inches but this thing goes. Used to have it on an electric motor I needed to run cool.

[TopCatGr58]

Hey Bones,

From what I've seen/heard, the oil coolers only drop/cool the oil temps about 10-20 degrees...but I don't have any hard data on that. As was stated, in '81 they designed a cooler adapter plate that bolted onto the engine/crankcase where the oil filter cup fits, and then the filter cup fitted below that. I don't recall for sure, but I don't think the setup had/used a thermostat oil flow control....but I have seen such a device in the B&M oil cooler parts. But being air cooled, unless you're riding in 30 degree temps at 60mph it'll be kinda hard to overcool it.

Aside from the adapter plate, we have seen where folks have spiced into the cam/topend oil supply tube on the back of the engine to supply for a modded cooler rig...but most folks feel that this design isn't so good because it causes a bit more time to occur during startups before the oil can push it's way thru the entire cooling radiator and hoses before it finally gets to the topend to lube the cams!

With the adapter plate, the route is closer to the oil pump, and also provides cooler oil throughout the whole engine and not just to the cams. I do make a customized adapter to allow the use of a spin on filter AND the oil cooler fittings, but due to health issues this last year I haven't been able to make any...by hand using a simple lathe/mill setup....no CNC! You can see an example of it in the For Sale Forum...parts/services by members sticky thread.

I can understand the air damns to try to route more air across the head/cylinders for extra cooling affect, but not sure how effective they will be, the engine is naturally fairly wide and so a fair amount of wind gets to it from around the front wheel/forks and would only be blocked IF you had a prominent FAIRING on there.....which is part of the reason why Yamaha put the cooler on the 81 Venturer....FULL FAIRING and lowers rig!

The extra fan is a great idea, surprised that it only draws that small amount of current 0.7 amps....so wondering how many CFM's it provides as well as how strong/speed the air being produced will be to make its way THRU the head?? As stated, the XS11's electrical system is very weak....and also doesn't start producing much charging current until the rpms get up to ~2500 rpm....so that can then cause additional problems even with that little current draw if you are just putting along barely above idle rpm.....folks have discharged their batteries just idling their bikes during carb tuning processes! SO....not sure if you'll have any storage bags or rack on the bike where you might be able to mount an extra 12V battery to drive the fan separate from the bikes electrical system for these memorial/parade runs!?

In that same For Sale thread....you'll see an advert for a Reg/Rect that a member makes that produces charging current at much lower rpms than the oem unit, but does not provide any EXTRA current, just charging at lower rpms!

On this same line of saving power....I think I saw you state about using LEDs...but then you said load resistors also! Load resistors DEFEAT the purpose of using LEDs! Most of the lights can be swapped for LEDS without the need for load resistors. See tech tips/Mods/Electrical for examples. The only ones that cause problems are the turn signals due to the THERMAL flash relay...that can be replaced with an electronic no load type and will THEN work with LED turn signals....provided the bike has dual turn indicators in the dash lights console. You will loose the self canceling feature...UNLESS you do the MOD that is posted with regards to this LED MOD, but many folks don't care/use the self cancel feature anyways...YMMV.

The 79 SF used a single indicator light, and so would allow backfeed current thru to the other side of the turn signal circuit and all 4 would flash...so Diodes are needed to be put on both sides of the indicator to fix this....but they don't cause any additional load strain compared to the load resistors!!! The other light that causes problems is the LOW FUEL idiot light on specials....so that one has to be kept an incandescent bulb in that one.

T.C.

[Boneswig]

Finally a reply with information that makes sense and is usefull. Thanks T C. Will go look at the section and use the info you have given. It one reply that answered more questions I had in one reply. Thumbs up on this one.