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Old 10-29-2006, 12:05 PM   #1
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TOO HOT!!!!

I HAVE A OFNA 1/8 BUGGY IT HAS THE .28 ON IT I CANNOT GET IT TO RUNN COOLER TEMPS IT RUNNS ABOUT 290 TO 300 DEGS EVEN IF I RICH THE MOTOR UP IT MAY DROP TO 280 OR SO I PUT A COLDER GLOW PLUG IN IT THINKING THAT MAY HAVE BEEN THE PROBLEM BUT NOT I WAS RUNNING 30% BUT CHANGED IT TO 20% THINKING THE FUEL WAS BURNING TO HOT I DONT KNOW IV BEEN RACING R/C FOR 6+YEARS AND NEVER RAN INTO THIS ...WELL MAYBE SOME BODY CAN HELP THANK FOR YOUR HELP AND KEEP RACING R/C!!!!!
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Old 10-29-2006, 12:08 PM   #2
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I'm wondering if there might not be an air leak somewhere that's throwing off your engine mix?
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Old 10-29-2006, 12:19 PM   #3
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Empty you fuel tank. Now make sure the lid is sealed by pushing the lid down. Take the fuel line off the carb and the pressure line off the pipe. Hold the end of one sealed by your finger. Now blow into the other line. If you go red in the cheeks, your tank is fine. If not, check all the fuel line's, and finally, the tank. Replace if required.

Next, check around the motor. The backplate, the carb, the head, check them all for deposit's of oil and dirt that shouldn't be there. That's another tell tale sign of a leak.
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Old 10-29-2006, 01:26 PM   #4
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More Nitro in your fuel actually keeps it cooler dude.
Thats if you have it tuned right. Ever spilt Nitro on ur hands?

Its freezing cold. The only other reason i can think of is a problem we have encountered. The engine may be under stress because somewhere on the internal is not lubricated so its metal on metal and its ceasing up and getting hot.
Usually its the crank pin to the bottom of the conrod, pull it down and have a look, if the crank pin is PURPLE its ceasing up and its getting hot. Take it off and put some oil on it of some sort ( Caster , Klotz ) and well lubricate it.

Other than that i cant think of anything else making ur engine 300 Degrees!


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Old 10-29-2006, 01:30 PM   #5
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yes an air leak does sound to be causing you difficulties. sometimes its the rubber o-ring on the lid of your fuel tank.

also 30% runs cooler as there is more nitro and it fires off easier. with 20% in a big block motor you get what is called detonation and this causes high engine temps by about 10 to 15 degrees plus your not getting the most out of your motor. the parts inside the motor ,for what they are, are large and take alot of force to move them at the rpm's these motors run as well as the compression, with the lower % fuel there is not enough explosive force to move it all efficiently thus causes high temps.

good luck
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Old 10-30-2006, 07:38 PM   #6
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If your running a Ofna Mach .28 engine, then thats normal. i have the same car myself and after reading numerous threads and seeing other people with the same car. we've come to the conclusion that the car carb design is crap and it doesnt hold the needles in place - which makes it very difficult to tune.

You will either get good speed and very high temps or no speed and (decent temp). i run my car in the 220-250 degree mark, if the engine blows up so be it!
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Old 11-01-2006, 12:22 AM   #7
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If there is a low speed needle, its too lean. Richen it by unscrewing it 1/8 to 1/4 and see what happens.
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Old 11-02-2006, 07:38 PM   #8
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Thumbs up ok

ok thanks for all the tips and hints i did find a air leak on the back plate i thinks i have fix it i will try it this weekend and see what the temps are and yea some body told me that these motors are not too great and they do run hot i will try it this weekend thanks for the help all of you and keep racing.........

Marc Nichols
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Old 11-02-2006, 08:35 PM   #9
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if you have taken motors apart before you can put red silicone anywhere that might have a leak.. carb hole,back plate, etc.. i had that problem with the force .28 and it quit after that.. air leak is the most comon problem on these force engines..
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Old 11-02-2006, 09:26 PM   #10
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Cool ok

ok thanks for all your help i have been racing nitro for a long time and i know air leaks and stuff like that will make the temps go up but not like this i think i found the problem im going to run it saturday i may go racing out at maddmax's track here in Trussville Alabama well thanks to all i think im going to order a new .21 anyway and take the force off well later and thank you again and keep racing........

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Old 11-03-2006, 08:25 AM   #11
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Quote:
Originally Posted by rcracer34
I HAVE A OFNA 1/8 BUGGY IT HAS THE .28 ON IT I CANNOT GET IT TO RUNN COOLER TEMPS IT RUNNS ABOUT 290 TO 300 DEGS EVEN IF I RICH THE MOTOR UP IT MAY DROP TO 280 OR SO I PUT A COLDER GLOW PLUG IN IT THINKING THAT MAY HAVE BEEN THE PROBLEM BUT NOT I WAS RUNNING 30% BUT CHANGED IT TO 20% THINKING THE FUEL WAS BURNING TO HOT I DONT KNOW IV BEEN RACING R/C FOR 6+YEARS AND NEVER RAN INTO THIS ...WELL MAYBE SOME BODY CAN HELP THANK FOR YOUR HELP AND KEEP RACING R/C!!!!!
One thing I have seen many times is innacurate temp guns or sensors. 290 is just above what could be considered the normal high end of the temperature range. Check your temp monitors against one that you know is accurate.

I doubt you have an air leak. If you did, you would be complaining about impossible tuning and a tune that changes for no reason. And if too lean you would see the engine cut out at high RPM, and overrun when you release the throttle.

Other than than the possible temp issue, it sounds as though your engine is running fine. The way the engine operates is more important than the temperature. If it runs great, leave it. You can use temperature as a tuning tool, but engines should be tuned to operate properly, not so they remain in a specific temp range.
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Old 11-03-2006, 11:45 AM   #12
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Cool temp gun

ok this could be true when i run it there is blue smoke coming out of the pipe i think i have a very small leak on the back plate but i think i fixed it now. but im thinking the same that the temp gunn is off some it is a UEI temp gunn well thanks again i hope thats all it is...

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