How HOT is too HOT ?

[militarymaxx]

I have a GS Storm with the stock .21 engine in it. It broke in just fine and actually thought it could still be leaned out a bit for some more top end but left it alone. The other day at the track I had a guy check the temp and it was reading 300 degrees. I was done for the day anyways but made a point of making adjustments the next time out. Well today I ran it again. Nice spring/summer day, 75 degrees partly cloudy (you get the picture). And using my newly purchased temp gage, it was still reading 300-320 degrees. I have good smoke while running it and when I go to richen it in hopes of getting the temp to come down, it dies at high speed. So, I put the needle back where it was and I run it for 3 more tanks and no problems, no flameouts, nothing, but still 300 degrees. The book says 200-250, but I've heard of some guys running this hot. Any suggestions would be greatly appreciated. (Sorry for such a long thread).

 

[Kuma]

I have a similar issue with my XTM .18 and I think it's the O.S. #A3 plug I use, might have to try McCoy #8 or so. I've read OS plugs are hotter, what plug do you use?

When I richen it up, it still runs quite hot and dies when revving as well.

 

[militarymaxx]

I have been using McCoy MC-9 (recommended in the manual).
I purchased some O'Donnell ODO 099 but haven't tried them yet.
You think it might be that I'm running too hot of a plug ?

 

[RandyT]

MC-9 is a cold plug, a MC-8 is warmer then the MC-9. You might have to check for air leaks.

 

[militarymaxx]

I understand that if I'm getting air in somewhere, that it will run leaner due to the increase in air but what about my smoke trail ?
I get a nice trickle of blue smoke throughout my runs. I thought maybe the hole in the body wasn't large enough but ran it for a while without the body on and there was no change.

 

[RandyT]

I have a Savage and when I was running the .21BB no matter how hot it got, it still had smoke, go figure. Did you seal the carb and backplate up~?

 

[Kuma]

Are you testing it witht he body off? Might be lack of air flow (which is why most of us cut a round or square hole in the body's windshield these days). Could also be an air leak at the carb intake which won't affect the mid-top end much. Also turn the low speed needle out (richen) at least 1/8 of a turn each time until it starts stalling when accelerating and see if that changes anything in running temps. Problem with these nitro engines are multiple possibilities when something is wrong. :whhooo:

 

[militarymaxx]

I checked the low speed needle and it is all the way in. This means lean at the low to mid range ? This would make sense as I'm only using low to mid throttle throughout the track.

 

[Kuma]

Your low speed is all the way in as in bottomed out???? OI! Screw it out until it surfaces with the throttle arm at least and go from there (that would be around 3.5 turns). My XTM's factory LSN was 5 turns out and that's well past flush and it is far too rich for me.

 

[militarymaxx]

Yep. All the way in. Was like this from the factory. It's my fault, the manual mentioned adjusting the LSN after the HSN was set. It just seemed to run fine after the 5 tanks of break-in, that I adjusted the HSN and left it alone. Everything is clearer now. I get good smoke, but only during mid to hi speed runs (which tells me that my HSN is good). But at idle or low speed running, not much if any smoke and that would explain the overheating. Hopefully I haven't done too much damage to the motor. I have runs about 8-10 tanks through it and the after run maintenance is always throughly done. Let me know if I'm on the right track and Thanks for all the help.

 

[RandyT]

All the way in~? Did you motor idle~?

 

[big kal]

Once you have LSN set, check if your temps are still high. If they are you might have an air leak somewhere, even if there is still lots of smoke coming from the pipe. Your car was able to idle?

 

[militarymaxx]

The car idles fine, maybe a tad high, but not enough to engage the clutch. The only things I have adjusted on it are the HSN and the idle (which I did with the controller). But haven't touched the LSN at all. Didn't get a chance to take it out this weekend, too much rain. Instead I spent time on upgrading to a 5 cell NiMH pack and a failsafe. Based on the feedback I have gotten here, I'm confident it's the LSN adjustment that's causing the temp to run high. My only concern now is after I adjust the LSN, what will I have to do with the idle and the HSN. Does one adjustment affect the other ?

 

[RandyT]

Do you have the factory settings for the needles~? I would change everything back to factory and start from there. Second, it is not recommended to adjust idle by using your controller, use the idle screw. The LSN only affects the low end and idle of your motor, top end is all HSN. The LSN controls the amount of fuel reaching the carb when closed and slightly above, it should not effect your temps at WOT.

 

[militarymaxx]

I really messed up. Stupid me got the idle screw and the LSN screw mixed up. I struggled with the buggy the other day and got to the point where it wouldn't start, just blow raw fuel out of the exhaust. It was ugly. I managed to get it back to where it would run like it did and actually it ran somewhat cooler. Anyways, I would love to set things back to the factory settings, but don't know what they are. The only adjustment I did during and after breakin was the HSN. But after this latest run, everything is different. I could use some baseline settings if anyone has them on the GS Storm .21BP01 engine, something to get me close.