Changed gears, now runs hot

[some_evil]

Hi all, I recently changed my gears on the slayer pro to the 17 tooth bell clutch and 38t spur gear ratio. Ran it for the first time and it had great top speed, very happy with it running on my local oval.

But after bout half a tank of fuel I noticed minor smoke coming from engine (around the cooling fins) so I turned off and rested it. After 30min I tried again, same thing happened.

I'm a little worried that changing the teeth may have changed something I'm unaware of. Do I need to re tune motor? It was great on standard tooth set up, only change is gearing.

The only other thing that I think it could be is that I cleaned the motor with a rag covered in Wd40 after changing gears over. It could be burning off that oil??

I have a thermometer does any one know what temperature it should be after half a tank flat out running???

Thanks guys, I'm a bit worried to run it without some further investigation.

Cheers

Sent from Tapatalk on my S3

 

[NitroHawk]

Temps should be in the 210/270 range according to traxxas.

 

[RC/Racer]

Max Temp's should not Exceed 270.... I try not to run hotter than 250-260 with my TRX engines in my Rig's...

 

[tmaxxfreek]

I ran ALL my 3.3 between 270-295 and had no problems with them, last one i ran i got over 7 gallons thru it, IMO the run better at 27 than they do at 210, granted i may have gotten 10+ gallons out of the lastone if i ran it at 210.....just my .02

 

[Zdragon71]

My 2.5r ran best at 280. Hell even my picco .26 max runs best around 275.

 

[some_evil]

I'll be getting slayer out before the weekend and checking actual temperature. Cheers

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[tmaxxfreek]

Run your temp at whatever you feel it runs best at, but you can't tune to temp ranges either, yours may run better at 240 than mine did. follow the tune chart in the nitro section, works everytime and is very simple to follow.

 

[some_evil]

So I know I'm doing it right, where do I shoot the temp gun? Into centre core of motor, down by the glow plug?
I assume if I shoot the blue starter wire it will not be a true reading.
Cheers

Sent from Tapatalk on my S3

 

[tmaxxfreek]

Shoot the temp gun down on top of the glow plug. the blue starter wire will not give you a correct reading.

 

[frickenjoey]

Maxxfreek is correct on the shooting the temp. The taller gearing adds an additional load to the engine. With that higher load comes higher temps. That is why you are now running hotter. What was the stock gearing you changed from? Sounds like you need to gear back down a little. I would try re-tuning first and if that does not work then you need to change your gearing back a little. I would start with the spur first...

 

[Zdragon71]

I agree. Try going up a tooth or two on the spur gear first. Also you could try richening the hsn in small increments to see if that helps any. Running all out for half a tank would get my engines way hot. If i run my picco wide open for too long it wants to hit 290-300. I just keep close watch on temps and try to stay away from wide open running non stop. I'm sure you will be able to find a happy medium between tuning and maybe a couple more teeth on spur. Good luck with it and hope this helps.

 

[Childresshunt]

not to mention all that wo running wears your engine faster. I bought a new motor for my hpi firestorm and i did a ton of wide open passes about 2.5 gallons later that motor was shot. Although this was my "teaching myself how to tune engine" still sucked it only lasted that long