engine temp

one more question -

how hot should the engine get? i don't know whats too hot and whats normal. mine gets fairly hot - (too hot to touch), and sometimes when i come to a stop after having ridden for a while i can feel the heat drafting up some around my neck/head.
also, the right side seems to be hotter than the left. is maybe one cylider overcompensating for another - maye check the plugs? (not sure i know what i'm talking about here -

thanks - nathan

 

Are we still talking about your XJ550 here?

Z

 

i think about 250 to 300ª f ... no?

who has a temp gauge in their bike?

 

Good question. I haven't the foggiest. I'll be getting one of those newfangled InfraRed themometers/pyrometer toys from Harbor Freight this weekend, saw them on sale for under $40. We just covered the operating temps on the paint for motors thread on the XJ Chat forum. Check it out, one of the fellows did post measurments.

 

I was just reading the latest issue of Cycle World and in the Question & Answers section someone wrote in asking what the normal operating temperature is supposed to be for his Suzuki SV650. Here is what this magazine said. Ideally, the manufactures like the engines to run right around 190-200f degrees, a range that strikes a good balance between being hot enough to help reduce exhaust emissions( by burning those last remaining combustibles before they rush out the exhaust) and not so hot as to cause pre-ignition or other heat related engine problems. Sometimes, for example in slow traffic on a hot day or when lugging up a long hill, the temperature can rise to 210-220 degrees. If however the temperatures climb too high, serious engine damage can result. The oil can lose enough viscosity to begin allowing metal to metal contact between interacting components, and the combustion event can be triggered prematurely by the surface heat of the valves, cylinder head and piston. That irregular combustion can burn valves, melt piston crowns and cause piston seizures. The engineers at Suzuki apparently have determined that 248 degrees is the critical temperature on the SV650. In all likelihood, the SV engine can withstand even higher temperatures than that, but Suzuki, like all manufacturers, chooses to err on the safe side rather than recommend a temperature that is right on the edge of destructiveness.

 

Very enlightening CT, glad you get the magazine instead of me, my wife would kill me if I brought home one more subscription. I'm filing this one away. One point that should be recalled is that the XJ is an air/oil cooled engine and the numbers you mention sound exactly like the numbers I would expect from a water-cooled engine (current emissions laws make make engineers design engines that work at these temps for the very reasons you mentioned. Older aircooled motors tend to be a bit hotter to my experience, but I haven't the evidence to support my perspective since I've never pulled out a thermometer to check (so much for my credibility). I'll qualify my statements by claiming them and admitting no emperical support (yet). I will offer this in my defence, my air-cooled VW regularly showed head temperatures of 380 F. I should have been a little lower but I lacked the knowledge and money at the time to do very much about it.

 

i just bought a temp gauge for another bike

and it says normal temp should be 250 to 300ªf