Topic: 750 keeps breaking down oil, overheating?

[killersoundz]

I am using regular dino oil in my 750k4. I'm on my 3rd oil change in about 1000 miles since the rebuild. I'll be out in hot weather city riding and sometimes the bike just gets SO hot. I need to get a infrared temperature gauge and take a reading of the oil tank but I bet it has hit 300 or more oil temp.

After an overheating or two like that and a few hundred miles the oil just doesn't feel slippery anymore, it just feels sticky, and the viscosity appears thinner.

I can also tell when the bike is either over heating or the oil is getting worn out because the gear selector itself will start to feel really sticky. Like if I am coming out of 5th gear trying to take it back to 1st, it will literally be sticky going through those gears. After an oil change goes right back to normal.

Are these motors in particular known for killing oil like this? What can I do to help?

I was reading an interesting write up about oil breakdown

http://www.off-road-outdoors.com/Oil-breakdown.html

[Duke McDukiedook]

When you say regular dino do you mean car oil or moto specific oil as is JASO MA certified oil?
It is possible to overheat the engine if you do too much city traffic stopping without having air to run over the engine and cool it. These bikes like to run.

[killersoundz]

When you say regular dino do you mean car oil or moto specific oil as is JASO MA certified oil?
It is possible to overheat the engine if you do too much city traffic stopping without having air to run over the engine and cool it. These bikes like to run.

I've been using car oil without friction modifiers.

I'd think the next step up is synthetic oil that can take higher temps and has high shear resistance. Well next season at least. It's cooling off over here now and the bike likes that.

And yeah I hear ya I'll just shut the motor off sometimes if I am sitting at a stop too long. The bike is hard to keep cool in hot weather even if you're constantly moving though.

[Bailgang]

I'm not saying it's the problem nor am I trying to dis you but I would definitely try something better than the walmart supertech oil you mentioned you used in another post.

[killersoundz]

I'm not saying it's the problem nor am I trying to dis you but I would definitely try something better than the walmart supertech oil you mentioned you used in another post.

Haha yes! I'll pull the cap off the oil tank when the bikes been at it's peak temps and the oil will be smoking.

I might try some synthetic motorcycle oil next summer since the motor is broke in now. I'm actually planning on pulling the motor back out to change the cam chain tensioner this winter. 

[powerplant]

Are you sure it's oil related?

I'd check your ignition system and your timing to be sure it's up to snuff and set properly.

[CycleRanger]

And make sure you're not running lean.
I almost hate to ask but what is your exhaust, air filter, and jets set up?

[killersoundz]

And make sure you're not running lean.
I almost hate to ask but what is your exhaust, air filter, and jets set up?

Yeah I think my midrange is running lean.

Currently, Pods, 4 into 1 straight,  big idle jets (keyster kit), and 130 mains. needle clips on the middle stock position right now though. Interestingly the idle is actually a little rich, and with the 130 mains my WOT is rich, but I think the midrange is lean where most of the riding is done.

[bollingball]

The kind of heat you are talking about is not normal. I did not see the weight of the oil? In the summer here in NC I go up to G4 20-50. Don't forget the trans. gears are chewing up this oil. With me it was a trial and error mine just feels better all around in the summer with this weight. On a hot 96 deg F day my oil temp stays about 170f +/- 5 deg. in the tank. I am not sure what it should read but it does not seem hot to me. I would not run mine if I thought it was 300+.
Ken 

[killersoundz]

The kind of heat you are talking about is not normal. I did not see the weight of the oil? In the summer here in NC I go up to G4 20-50. Don't forget the trans. gears are chewing up this oil. With me it was a trial and error mine just feels better all around in the summer with this weight. On a hot 96 deg F day my oil temp stays about 170f +/- 5 deg. in the tank. I am not sure what it should read but it does not seem hot to me. I would not run mine if I thought it was 300+.
Ken

Yeah I use 20w50 as well. I'll need to get a thermometer to see what the temp really reads. Tonight I took it for a ride tonight and it's about 60F out and it was fine I could idle it at red lights all day long, but 96F like you say, no way with my bike!!

[lucky]

I grew up in Tucson and it was 114º in the summer. We liked to drive at night when it was only 90º.

When it gets that hot the cars with weak cooling system show up right away.

General Motors have ads that say, "We test our vehicles to the extreme heat of 100º."
Tusonians just laughed.

You can imagine how much we liked it when anti freeze came into use.
Then Wynn's quick cool.

Air cooled VW's - Big external oil coolers and extra 2 qts. of oil.

Lots of tricks.

[lucky]

And make sure you're not running lean.
I almost hate to ask but what is your exhaust, air filter, and jets set up?

Yeah I think my midrange is running lean.

Currently, Pods, 4 into 1 straight,  big idle jets (keyster kit), and 130 mains. needle clips on the middle stock position right now though. Interestingly the idle is actually a little rich, and with the 130 mains my WOT is rich, but I think the midrange is lean where most of the riding is done.

Still got those clips on the middle position? With PODS? Maybe a complete engine seizure will be instructional.

[killersoundz]

And make sure you're not running lean.
I almost hate to ask but what is your exhaust, air filter, and jets set up?

Yeah I think my midrange is running lean.

Currently, Pods, 4 into 1 straight,  big idle jets (keyster kit), and 130 mains. needle clips on the middle stock position right now though. Interestingly the idle is actually a little rich, and with the 130 mains my WOT is rich, but I think the midrange is lean where most of the riding is done.

Still got those clips on the middle position? With PODS? Maybe a complete engine seizure will be instructional.

Yeah I hear ya. I might go out to the garage and change them and see how it is. The thing is, the last 3/4 to WOT it's actually running rich with the 130 jets. CARB TUNING, sucks. Should have just put a stock intake on!!

[bollingball]

Yeah I hear ya. I might go out to the garage and change them and see how it is. The thing is, the last 3/4 to WOT it's actually running rich with the 130 jets. CARB TUNING, sucks. Should have just put a stock intake on!!
It is never to late and might not be to hard to do with a 750K4.
Don't get me wrong when it is 96f my bike does not sit at idle very long You have to keep moving. Heck I don't like my helmet when it is that hot. I think or hope you will find it is not 300+ if so like said look for other causes.
Ken

[madmtnmotors]

I run 10-40 Valvoline year-round here in Central Florida and have no trouble going 1500-1800 miles between oil changes. We're in the 90's from May through October. The only time I had overheat issues like you describe is when I had the bright idea to cap the crankcase vent (at the back of the valve cover). Blued the pipes and smoked any trace of oil off the outside of the engine in short order. Quickly realized the error of my ways and restored the vent to working order. That was about 30,000 miles ago, currently showing 60,000 on the odometer, so hopefully I didn't do any real harm. The intake mods you've got could create a lean condition as others have indicated. Whatever it is you need to figure it out quick, these motors are hardy, but they can only take so much. Somethings not right.

[killersoundz]

I run 10-40 Valvoline year-round here in Central Florida and have no trouble going 1500-1800 miles between oil changes. We're in the 90's from May through October. The only time I had overheat issues like you describe is when I had the bright idea to cap the crankcase vent (at the back of the valve cover). Blued the pipes and smoked any trace of oil off the outside of the engine in short order. Quickly realized the error of my ways and restored the vent to working order. That was about 30,000 miles ago, currently showing 60,000 on the odometer, so hopefully I didn't do any real harm. The intake mods you've got could create a lean condition as others have indicated. Whatever it is you need to figure it out quick, these motors are hardy, but they can only take so much. Somethings not right.

Speaking of that vent you 'capped off'. I don't have mine hooked up to anything, it's supposed to have a little hose going to the top of the oil tank right? I never hooked it up since the rebuild just sort of forgot about it.

[killersoundz]

I raised the needles up a notch tonight. With the 130 mains. Took it for a ride and yeah the midrange is definitely better. I had the needle clips in this position when I had the 115 main jets in but took them back to stock when I started messing with the bigger main jets. Couldn't tell if it's running any cooler since it was like 45F out (coooooooldddddd ride)

[ekpent]

I run 10-40 Valvoline year-round here in Central Florida and have no trouble going 1500-1800 miles between oil changes. We're in the 90's from May through October. The only time I had overheat issues like you describe is when I had the bright idea to cap the crankcase vent (at the back of the valve cover). Blued the pipes and smoked any trace of oil off the outside of the engine in short order. Quickly realized the error of my ways and restored the vent to working order. That was about 30,000 miles ago, currently showing 60,000 on the odometer, so hopefully I didn't do any real harm. The intake mods you've got could create a lean condition as others have indicated. Whatever it is you need to figure it out quick, these motors are hardy, but they can only take so much. Somethings not right.

Speaking of that vent you 'capped off'. I don't have mine hooked up to anything, it's supposed to have a little hose going to the top of the oil tank right? I never hooked it up since the rebuild just sort of forgot about it.

The vent at the back of the valve cover goes to the atmosphere and the vent at the bottom back of the crankcase goes to the oil tank.

[754]

 Check it with an oven thermoeter, you may just think its overly hot. CB 750 can easily hold another qt in stock tank.. I put that in if crossing deserts..

[CycleRanger]

Check it with an oven thermometer, you may just think its overly hot. CB 750 can easily hold another qt in stock tank.. I put that in if crossing deserts..

Lotta deserts in BC? 

[754]

There is a small desert south of here..80 miles, it gets fairly hot here too.
 But I was refferring to rides I did in the past like El Paso to SanDiego in under a day, LA to Sturgis.. Sturgis back to LA. At Bonnevile you ride thru some high desert, can get pretty hot there and on the salt.
 A bit south of here around Lewiston, was 41C when my buddy rode thru..

 If I know I will be riding in steady 100F, I add extra oil..

[CycleRanger]

Yes, I figured you'd been around. Yeah, there's a little desert south of you called eastern Washington!

[madmtnmotors]

I run 10-40 Valvoline year-round here in Central Florida and have no trouble going 1500-1800 miles between oil changes. We're in the 90's from May through October. The only time I had overheat issues like you describe is when I had the bright idea to cap the crankcase vent (at the back of the valve cover). Blued the pipes and smoked any trace of oil off the outside of the engine in short order. Quickly realized the error of my ways and restored the vent to working order. That was about 30,000 miles ago, currently showing 60,000 on the odometer, so hopefully I didn't do any real harm. The intake mods you've got could create a lean condition as others have indicated. Whatever it is you need to figure it out quick, these motors are hardy, but they can only take so much. Somethings not right.

Speaking of that vent you 'capped off'. I don't have mine hooked up to anything, it's supposed to have a little hose going to the top of the oil tank right? I never hooked it up since the rebuild just sort of forgot about it.

As long as you're venting you're fine. Fortunately when I capped mine that had been the only modification so it was easy to diagnose. Typically a hose is routed back to the air cleaner or down near the centerstand. If it just open to the atmosphere with no hose connected you may get some oil mist. If the oily discharge becomes a nuisance you can always route a hose down low. Some owners have also used a small filter to help control any excessive oily discharge.

[killersoundz]

I run 10-40 Valvoline year-round here in Central Florida and have no trouble going 1500-1800 miles between oil changes. We're in the 90's from May through October. The only time I had overheat issues like you describe is when I had the bright idea to cap the crankcase vent (at the back of the valve cover). Blued the pipes and smoked any trace of oil off the outside of the engine in short order. Quickly realized the error of my ways and restored the vent to working order. That was about 30,000 miles ago, currently showing 60,000 on the odometer, so hopefully I didn't do any real harm. The intake mods you've got could create a lean condition as others have indicated. Whatever it is you need to figure it out quick, these motors are hardy, but they can only take so much. Somethings not right.

Speaking of that vent you 'capped off'. I don't have mine hooked up to anything, it's supposed to have a little hose going to the top of the oil tank right? I never hooked it up since the rebuild just sort of forgot about it.

As long as you're venting you're fine. Fortunately when I capped mine that had been the only modification so it was easy to diagnose. Typically a hose is routed back to the air cleaner or down near the centerstand. If it just open to the atmosphere with no hose connected you may get some oil mist. If the oily discharge becomes a nuisance you can always route a hose down low. Some owners have also used a small filter to help control any excessive oily discharge.

Right on. I checked it and I would assume any air pressure coming out of there would be blow-by from worn out rings and stuff. Thankfully I just rebuilt my motor and you can just feel a slight pulsation when I put my finger over that vent but nothing much. Now if I pull the oil filler cap off my 180,000 mile honda accord motor, it blows real hard, lots of blow by!