• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

Overheating

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
knights

knights

RCTalk Basher
Messages
72
Reaction score
0
Points
0
Location
Robbinsville North Carolina
RC Driving Style
Temp gun reading 260 to 310 on pro 15. But I have a lot of smoke on low end and a little smoke on top end. I think I have it to rich, so why would it be running so hot.

Also if I just rebuild it what do I need to replace? I know the piston and sleeve. What about the arm for the piston? Also how about any thing else I would need to replace? I am buying another engine for different truck so I am trying to get by I cheep as I can on this engine. Next year I will get another engine for this one, but 4 now I would like to rebuild it.
 
Last edited:
knights said:
Temp gun reading 260 to 310 on pro 15. But I have a lot of smoke on low end and a little smoke on top end. I think I have it to rich, so why would it be running so hot.

Also if I just rebuild it what do I need to replace? I know the piston and sleeve. What about the arm for the piston? Also how about any thing else I would need to replace? I am buying another engine for different truck so I am trying to get by I cheep as I can on this engine. Next year I will get another engine for this one, but 4 now I would like to rebuild it.
Click to expand...

Do you have holes cut out of the body for enough airflow? Maybe you are running a little lean? When bashing there should be a good amount of smoke throughout the powerband. What are the outside temps your running in?

Personally I wouldn't rebuild the .15 pro. If you were to rebuild it, you would want to replace the sleeve, piston and connecting rod. Not to mention bearings, you would either want to clean or replace them. You would end up spending around $50 for just the sleeve, piston and con-rod when you can get a brand new 3.3 for $100.

I just blew my .15 pro a week or so ago, I was faced with the option of rebuild or buy a new engine. Needless to say a 3.3 is getting ordered soon.
 
andydrew39219 said:
Personally I wouldn't rebuild the .15 pro. If you were to rebuild it, you would want to replace the sleeve, piston and connecting rod. Not to mention bearings, you would either want to clean or replace them. You would end up spending around $50 for just the sleeve, piston and con-rod when you can get a brand new 3.3 for $100.

I just blew my .15 pro a week or so ago, I was faced with the option of rebuild or buy a new engine. Needless to say a 3.3 is getting ordered soon.
Click to expand...

i agree with this^^^ i blew my 15 and went 3.3 the difference is unbeileveble
 
madd802 said:
i agree with this^^^ i blew my 15 and went 3.3 the difference is unbeileveble
Click to expand...

Not trying to derail, but I am so excited to stick a 3.3 in my maxx. I have only ever experienced the .15 pro. I'm the only one in my small town with a nitro.

Do you know if you have the narrow maxx knights? I think you can stick the 3.3 in the narrow max without problems, but you would be best off converting it over to the wide maxx. I don't believe it takes much, probably new a-arms, axle carriers and the driveshafts that go to each wheel. Can someone confirm this for me?
 
If you think your tune is right you could have a tight mesh that's causing it to run hot. Could also be a bearing going bad. It all puts an extra load on the engine.
 
The first thing to do whenever you think your engine is running hot is to richen the hsn until you know for sure it's too rich, then lean it back a little. I've seen a lot of people who thought there engines were rich but they were actually lean.
What makes you think it's running rich anyway? Is it slow off the line? Is it because there's smoke?
 
andydrew39219 said:
Do you have holes cut out of the body for enough airflow? Maybe you are running a little lean? When bashing there should be a good amount of smoke throughout the powerband. What are the outside temps your running in?

Personally I wouldn't rebuild the .15 pro. If you were to rebuild it, you would want to replace the sleeve, piston and connecting rod. Not to mention bearings, you would either want to clean or replace them. You would end up spending around $50 for just the sleeve, piston and con-rod when you can get a brand new 3.3 for $100.

I just blew my .15 pro a week or so ago, I was faced with the option of rebuild or buy a new engine. Needless to say a 3.3 is getting ordered soon.
Click to expand...

Lot of smoke on low end, but not a lot on top end. Yesterday the outside temp us 50 or so. High elevation though.
This truck would not handle a 3.3. Short wheel base. It also will climb better than any other truck I have seen before it gets to hot. I think it climbs good because it don't have enough power to spin a lot. Sort of like a jeep or Toyota.

---------- Post added at 3:39 PM ---------- Previous post was at 3:28 PM ----------
2revo1maxx said:
The first thing to do whenever you think your engine is running hot is to richen the hsn until you know for sure it's too rich, then lean it back a little. I've seen a lot of people who thought there engines were rich but they were actually lean.
What makes you think it's running rich anyway? Is it slow off the line? Is it because there's smoke?
Click to expand...

Cause it burns the heck out of my hand. lol.

Really though. Saturday it started running good but alittle week feeling. Then after about half a tank I rolled over and it was about 300 degrees and would not start easy. I gave alittle gas and got it going but it was so week it would not even hit 2nd gear. I have the HSN set at 3 1/2 full turns out. So folks would call this 7 turns out, depending on what you call a turn on the HSN. Just like a clock makes a full turn when it goes from 12 to 12 is what I call a full turn out. So If on 3 1/2. I had it running good the other day but it was almost 70 degrees outside that day. I got my friends revo doing a wheelie and his 2.5 running better. I think I can get it if I keep on trying but then the next day it will be out again.
 
So you know it's running rich because it burns your hand? That doesn't make sense.
I can guarantee you that it's not running rich, that's why I say you should try richening the hsn some more. Don't worry about low end power right now, just run it as rich as possible while still having the most top end power. Then start working on leaning the LSN.....and make sure the idle gap is correct too.

If it still overheats with a rich hsn setting I'd say it has an air leak.

You have to adjust the tune every day due to slight changes in the weather. It may be 70° from one day to the next, but humidity matters too.
 
The little pro.15 engine likes to run hot. 270F is very common with a good tune. Little engine, 10lb truck, climbing hills = temp spikes real quick.
 
Haft to say its running lean considering 4.5 is factory turns on the hsn and your a full turn in, in cooler temps. I had mine out to 5 in the 60s here.
 
Stock carb settings for the Pro.15 engine:
HSN 2.5 turns out from closed
LSN 1.75 turns out from closed
Idle gap 1/1.5mm
 
Snook Man said:
Stock carb settings for the Pro.15 engine:
HSN 2.5 turns out from closed
LSN 1.75 turns out from closed
Idle gap 1/1.5mm
Click to expand...

See there I went speaking before I read everything......retracting my previous statement.
 
Rolex said:
If you think your tune is right you could have a tight mesh that's causing it to run hot. Could also be a bearing going bad. It all puts an extra load on the engine.
Click to expand...

Same bearings for over 12 years. lol. Could be making it run hot, that's for sure.

---------- Post added at 9:35 PM ---------- Previous post was at 9:29 PM ----------

I have it 3 and half full turns out. Seems like I can get others engine tune okay and some days mine. I have checked my motor for air leaks. Had 1 in tank. Only checked about 70% of my engine. Need to cheek both again I guess.

---------- Post added at 9:37 PM ---------- Previous post was at 9:35 PM ----------

I'm going try starting at 4 out when this snow gets over. Not going get over 40 or low50s here in MTNs North Carolina until next Saturday.
 

RC Builds

Back
Top