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Hey guys, me again. I appreciate all the help I've gotten on this forum and thought it worth asking if anyone has any ideas on this issue.
My 1980 ltd gets incredibly hot every time I ride. It has a small oil cooling radiator added on but I'm not even sure the oil is pumping through it. I've owned 6 or 7 bikes and never ridden one that gets so hot, as in everything touching the engine almost. I'm worried the oil isn't circulating well?
I really don't know where to even start to find this problem. I've put a new pipe, same Mac 4 to 1 that was on it before and 530 chain with 2:36 ratio but it's been running hot ever since I bought it a few months back. The oil cooler is only ever slightly warm to the touch which is likely just due to it's proximity to the pipes. Thanks for any ideas. Lex

You could look into getting a thermometer to check temps. One like this for the surface of say the Head. Then the oil cooler, you could see if each tube in the cooler is flowing. www.harborfreight.com/non-contact-laser-thermometer-96451.html
Then you could always mount gauges, oil and cylinder head temp.
Are you plugs looking lean? Or is you Ignition advancer getting stuck?

Thanks. I'm going to pick up thermometer today. How do I know what the temps should be? Also, what's the best way to check the oil cooler?

First I would look at the condition of the fins, make sure there clean and not bent so Air can flow freely. If you have the surface temp thermometer, you can point it at each individual tube the crosses the cooler. This will sow an in coming temp and a out going temp. Sitting still with a large fan blowing on the motor would be best, during the warm up take readings. Then take it for a ride and recheck. This would be with both the oil, and cylinder head. Oil weight and viscosity can effect temps, as well as Type. Lots of threads on oil, and additives already.
Make sure that nothing is restricting the airflow to the engine or the cooler, such as body work. I know my 1000 runs hotter in traffic with the Vetter fairing. So luckily I can pick routes that have less traffic/ lights. its Air Cooled so best to keep it moving. Some bikes would have a fan at the oil cooler, or water radiator if liquid cooled.

lexor wrote: ...what's the best way to check the oil cooler?

One way to test for circulation through the cooler ---

Detach the hose from cooler exit nipple, and attach a temporary test hose with exit into a catch pan or bucket.

Next, spin the engine over by using the electric starter.

Oil should gush from the test hose, which shows it's passing through the cooler.

But if not, the next test would be to detach the hose from cooler input nipple, and allow the hose to exit into a catch pan or bucket.

Next, spin the engine over by using the electric starter.

Oil should gush from the hose, which shows it's reaching the cooler.

Reattach cooler lines and top up the crankcase oil before re-starting the engine.

Good Fortune!

I also meant to add that the engine itself being clean, underneath at the pan as it is ribbed/ finned, as well as the cylinders and head fins. This will make the transfer of heat to air much better. Dirt will cause much less transfer of heat to air, and hold the heat in.

I use a Sunpro mechanical water temp gauge with the probe mounted between 2 of the head cooling fins. I also have an oil pressure and oil temp gauge.On a hot day ,my bike runs 200 to 210 degrees oil temp and 180-190 cylinder head temp. I also have a large Satrab oil cooler and a belly pan that ducts air underneath the motor.Just as a reference point for u.Hope this helps.These old bikes do run hot in the summer.I can touch the exhaust pipes long before I can touch the engine after a ride.The oil gets hot and stays hot for a long time.Thats why good oil is so important.bj

Maybe these will help....

If this engine is stock and has not been bored out, it should not run hot even without the oil cooler. If on the other hand someone bored the engine out than it can run very hot. The easiest way to know that your engine is overheating is if your clutch tension/slack changes while you are riding. If you notice the clutch lever getting more and more slip in it as the engine heats up to almost the point where you cant pull it in than you are overheating. In my opinion, I would say that you are running too lean in the lower-Mid range. One of my bikes is bored out to a cylinder wall thickness of only .060 and it still runs normal temperature and I am not running a oil cooler. Also an oil that is too heavy can make you run hotter than normal.

Sorry to hijack this thread but while we are at it...

do anyone know the pumping rate (gpm/lpm) of a KZ oil pump ?

regards,
laurent

So I picked up a surface thermometer and after riding 2 miles and letting it idle 5 minutes got a reading of 340 f on the engine just above the exhaust exit. Other parts of engine in the upper 200s. Any suggestions? What's the worst case scenario? Thanks. So disappointing, and it's been running like this since I got it a few months back.

Oil, if not run hot enough won't boil/burn off the moisture from combustion. Causing acid buldup and other harmful affects. Water boils at 212 F (100 C) and to get the engine to this temperature may take a while, depending on ambient conditions and how long of a drive envolved.

What weight/grade of oil being used? How's the weather conditions? Mostly hot in the summer? Possible changing to a thinner oil might lower the engine temperature.

Best Oils To Use In Your Bike (Just My Opinion)

Engine oil : The commercial grade oils are clearly superior to the mass market oils. For the best protection in your bike or car, use Shell Rotella Synthetic, available at Wal-Mart in blue containers . For the best petroleum oil you can buy, get Shell Rotella T, Mobil Delvac 1300, or Chevron Delo 400, available at any auto parts store. On the back of most oil cans is a circular stamp with the certification. Avoid oils that say "energy conserving" in the bottom half of the donut. These oils contain friction modifier additives that could cause clutch slipping over time. All XXw-20 and XXw-30 oils are energy conserving, and should not be used in your motorcycle. Don't buy any oil additives like STP or Slick-50. Here's several listings on all about oil justifying these conclusions.

The Recommended Synthetic Oils :

Shell Rotella Synthetic
5w-40 Delvac 1 Synthetic
5w-40 Mobil-1 SUV/Truck Synthetic
5w-40 AMSOil AMF Synthetic (pricey, but it’s your money)
10w-40 Golden Spectro Synthetic
10w-50 Motul 5100 Synthetic
10w-40 Mobil-1 Synthetic
15w-50 Mobil-1 MX4T Synthetic

The best synthetics are: (in no particular order)

Shell Rotella-T Synthetic 5w-40 (blue container, not white), gallon at Wal-Mart.
Mobil Delvac-1 5w-40 (grey container, not black), gallon at Petro stations, gallon at Farm and Fleet.
Mobil-1 SUV 5w-40, qt anywhere.
AMSOil AMF 10w-40 synthetic motorcycle oil. (again, pricey)
Golden Spectro Supreme, (no price).
Motul 5100 Ester, (no price).

Mobil-1 automotive oils all contain small amounts of moly - about 100 to 200 ppm. This can cause clutch slippage in some motorcycles. I've only heard of this being a problem in Honda Shadows.

For temperatures below -40, I strongly recommend either Mobil-1 0w-30 or the Canadian Shell 0w-40 Rotella. At these temperatures, your car is your life. Using cheap or incorrect oil is risking your life.

For temperatures below -55c, -65f, stay home. Really.

The Recommended Petroleum Oils

Chevron Delo 400 15w-40
Delvac 1300 15w-40
Shell Rotella 15w-40

The best petroleum oils are: (in no particular order)

Chevron Delo 400 15w-40 (blue container) gallon at any auto parts store, gallons at Costco.

Mobil Delvac 1300 15w-40 (black container) gallon at any auto parts store, gallons at Sam's Club.

Shell Rotella-T 15w-40 (white container) gallon at Wal-Mart or any auto parts store, gallons at Sam's Club.

Castrol 15w-40 (Green container) gallon at Wal-Mart or any auto parts store, gallons at Sam’s club.

If you live in another country, you'll have to do a bit of research to decide on an oil. Generally, any oil certified for use in a late model Volks wagon or Mercedes turbo diesel is a good choice. Another good idea is to go to a truck stop and ask the truckers about brands. Rotella is marketed all over the world, but in other countries it's called Rotella or Rimola or Helix Ultra, and the formulation may be a bit different, depending on local climate and preferences. It will likely also be a lot more expensive than it is here.

PROTECTING THE 3 CRUCIAL ZONES OF YOUR ENGINE BY CASTROL
Castrol Trizone technology™ represents the 21st century approach to 4T motorcycle oils. Castrol 4T oils developed with Trizone technology™ offers the protection needed to get the most out of your motorcycle.

The 4T motorcycle engine, unlike the car engine, has a very compact oil system, where the engine, clutch and gear zones are combined and use the same oil. In a car engine, the three zones are separated, with the engine and gearbox using specific oils. The ideal 4T motorcycle oil has to meet the very different requirements in all three zones of the bike: engine, clutch and gears.

A CHANGING ENVIRONMENT
Europe is one of the most demanding motorcycle markets in the world: European riders demand performance, quality and versatility from their machines. Operating conditions vary from near desert heat in the south to sub arctic cold in the far north, from coastal plains to high mountain passes, from stop start city traffic to wide open motorways. Noise, gaseous emissions, consumer demands and safety to name a few have all had effects on motorcycle design. Increasingly, it’s the four-stroke engine that powers big bikes, with the two-stroke confined to use in small scooters, off road and competition. Today’s high-precision, high performance four-stroke motorcycle engine provides many challenges for its engine oil.

Motorcycle engines produce a lot of power for their weight. Part of the secret lies in high engine speeds: a truck engine produces peak power at about two and a half thousand RPM and a car
engine at around six thousand RPM. Modern four-stroke motorcycle engines can rev up to 15
thousand RPM or more.

The circulating oil comes under huge thermal stress as it transfers heat away from low mass components under high power conditions. High piston speeds and power output generate very high temperatures - with few places for that heat to go. The oil plays a crucial cooling role – which demands oils with exceptional high thermal stability. But there are many other challenges that a lubricant must face:

Poor quality oil can vaporise leading to a rapid rise in oil consumption - and a fall in protection.

Compact multicylinder multivalve engines use complex oil circuitry with narrow oilways - the oil needs to be fluid enough to keep flowing under all conditions.

Deposits can build up on the pistons and rings - the oil needs to keep these clean. All the while, the oil is carrying combustion by products and wear metals into the sump and filter.
Compared with truck or car engines, motorcycle engines are much smaller and lighter. Most four-stroke motorcycle engines and the lubrication systems are combined so that all these zones rely on the same oil: one oil to do three different but equally important jobs - to protect the engine, gearbox and clutch.