Carb adjustment advice.

[laseron]

I've rebuilt my 89 FJ, and am now doing minor adjustments for best idle and throttle response. The engine runs really well at all speeds,  with a stage 1 DynoJet kit installed years ago. I've got idle mixture screws adjusted at 2 1/2 turns out, with slight throttle hang-up after a blip test, indicating a slightly lean mixture. Turning the mixture screws out another 1/2 turn should help. I also need to check for intake air leaks around the airbox-to-carb interface, as this could lean things out as well.. I've installed the RPM oil cooler as well as an oil temp sensor, and I'm noticing the engine temp getting above 220 degrees in urban riding (frequent stops) in 70 degree weather. I'm wondering what the best jet sizes and needle position would be in the carbs to keep engine temps down. Or am I missing something? (Very likely).

[ribbert]

I've rebuilt my 89 FJ, and am now doing minor adjustments for best idle and throttle response. The engine runs really well at all speeds,  with a stage 1 DynoJet kit installed years ago. I've got idle mixture screws adjusted at 2 1/2 turns out, with slight throttle hang-up after a blip test, indicating a slightly lean mixture. Turning the mixture screws out another 1/2 turn should help. I also need to check for intake air leaks around the airbox-to-carb interface, as this could lean things out as well.. I've installed the RPM oil cooler as well as an oil temp sensor, and I'm noticing the engine temp getting above 220 degrees in urban riding (frequent stops) in 70 degree weather. I'm wondering what the best jet sizes and needle position would be in the carbs to keep engine temps down. Or am I missing something? (Very likely).

220 F is the MINIMUM temp for engine oil (not to be confused with coolant temp) so all's good.

Noel

[laseron]

Oh, that's good news. Having only recently installed an oil temperature gauge, for all those years I never knew what the oil temp was one a typical ride. Now that I can monitor it, it's almost an obsession- "oh, the temperature just ticked up another three degrees!" I really need to calm down and learn meditation.

[krusty]

Oh, that's good news. Having only recently installed an oil temperature gauge, for all those years I never knew what the oil temp was one a typical ride. Now that I can monitor it, it's almost an obsession- "oh, the temperature just ticked up another three degrees!" I really need to calm down and learn meditation.

"Zen and the Art of Motorcycle Maintenance" perhaps?

[laseron]

Read it. Loved it.

[ribbert]

Oh, that's good news. Having only recently installed an oil temperature gauge, for all those years I never knew what the oil temp was one a typical ride. Now that I can monitor it, it's almost an obsession- "oh, the temperature just ticked up another three degrees!" I really need to calm down and learn meditation.

Haha, that's why I don't like oil temp gauges. Unlike coolant temp where pumps, gaskets, hoses, radiators, thermostats etc can all cause engine overheating, oil on an air cooled engine doesn't really contribute to cooling it and it is what it is and sometimes you're better off not knowing, after all, you can't do anything about it.

For reasons I don't understand, it became common when quoting specs to refer to engines as "air/oil cooled" This misleading description has lead to a widespread misunderstanding about the role oil plays in cooling engines, which is basically nothing. Oil coolers just keep the oil cool. So, if your oil is not overheating, say 275 C+ you're good. And if it is overheating, what are you going to do about it?
Oil doesn't hit the wall and turn to water when it gets hot, it starts breaking down at around the above temp but still provides adequate lubrication for moderate periods well beyond that. Overheating air cooled engines are usually associated with high ambient temps and low speed (lack of air flow), not high stress such as in racing or even sustained high speed and will endure bouts of this without harm.

I make jokes about oil temp gauges being just another thing to worry over and about which you can do nothing anyway, and you are living proof, I love your honesty.

Noel

[Old Rider]

My car bmw f10 is from factory only equipped with a oil temp meter no coolant meter  

[Bones]

My two daughters both own Mazda's, one a cx5 the other a 3 and neither has a temp gauge of any sort. Not sure how your supposed to monitor the coolant temp or what happens if they blow a hose and overheat.

[Millietant]

Oh, that's good news. Having only recently installed an oil temperature gauge, for all those years I never knew what the oil temp was one a typical ride. Now that I can monitor it, it's almost an obsession- "oh, the temperature just ticked up another three degrees!" I really need to calm down and learn meditation.

Haha, that's why I don't like oil temp gauges. Unlike coolant temp where pumps, gaskets, hoses, radiators, thermostats etc can all cause engine overheating, oil on an air cooled engine doesn't really contribute to cooling it and it is what it is and sometimes you're better off not knowing, after all, you can't do anything about it.

For reasons I don't understand, it became common when quoting specs to refer to engines as "air/oil cooled" This misleading description has lead to a widespread misunderstanding about the role oil plays in cooling engines, which is basically nothing. Oil coolers just keep the oil cool. So, if your oil is not overheating, say 275 C+ you're good. And if it is overheating, what are you going to do about it?
Oil doesn't hit the wall and turn to water when it gets hot, it starts breaking down at around the above temp but still provides adequate lubrication for moderate periods well beyond that. Overheating air cooled engines are usually associated with high ambient temps and low speed (lack of air flow), not high stress such as in racing or even sustained high speed and will endure bouts of this without harm.

I make jokes about oil temp gauges being just another thing to worry over and about which you can do nothing anyway, and you are living proof, I love your honesty.

Noel

The first time I heard of an engine being air/oil cooled was in the marketing blurb from Suzuki when the launched the very first GSXR 750.

They talked about having oil jets spraying the underside of the piston to keep it cool and having a big oil cooler to get rid of the extra heat from the oil. The hype didn't last long before it was dropped from the marketing stuff and it was never mentioned again 

[fj1289]

But if you mention oil cooled Suzuki - most enthusiasts know exactly what family of engines you are talking about!

[ribbert]

My two daughters both own Mazda's, one a cx5 the other a 3 and neither has a temp gauge of any sort. Not sure how your supposed to monitor the coolant temp or what happens if they blow a hose and overheat.

Times have changed Tony, my car doesn't even have a dipstick for the auto transmission, it's "sealed for life" and the bonnet only ever gets lifted to top up the washers. No one even checks the fluid levels, tyre pressures or the lights, the car does all that. My bike even checks the engine oil level electronically before moving off.

Overheating and cooling system component failure used to be common, it's not any more and no one monitors temp gauges anyway, they never did. I think in this instance a big red light popping up on the dashboard is far more attention grabbing. 50 years ago we were installing auxiliary (the term 'aftermarket' hadn't been invented) temp lights to cars fitted just with gauges for that very reason.

I always find it odd that half the dashboard is taken up by the one instrument that is of the least use, the tacho. Modern engines can't be over revved and anything marketed to the boy racer segment has shift lights.

Noel

[ribbert]

But if you mention oil cooled Suzuki - most enthusiasts know exactly what family of engines you are talking about!

[krusty]

My two daughters both own Mazda's, one a cx5 the other a 3 and neither has a temp gauge of any sort. Not sure how your supposed to monitor the coolant temp or what happens if they blow a hose and overheat.

I don't know about Mazdas but my Subaru Forester and LDV van have a warning light in the dash (both are diesel) - no temp guages. And, if there was a problem, the computer management system would most likely light up as a warning.