R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric Off-Road

Thread Tools Search this Thread
Old 04-14-2003, 07:35 AM   #1
Tech Initiate
Join Date: Mar 2003
Location: northern virginia
Posts: 24
Default what is too lean??

i just got my new hyper 7 pbs up and running.. started breaking it in on saturday (such a beautiful day in maryland), and got through my first 2 tanks, running it super rich.. cut out on me a few times but it never got above 230 degrees F

sunday i mess around with it a bit more and get up to about the 4th tank and the temp got up to about 260, and i cut it off.. i was just putting it around and my LHS said that i should be driving it around a bit to keep the air flow going through the heat sink.. (my first r/c so it's all pretty new to me)

the engine would cut out on me with a cloud of blue smoke from the exhaust, if i gave it more than 1/4 throttle.. on the 5th tank i began to lean out the top end and the low end needles some, and it actually ran much better.. i could take it up to 1/2 throttle and it would fly.. anymore throttle, it would cut out.. so i gradually leaned it out a bit more, and by the time i got to my 6th tank it was just about dialed in..

i ran my 7th tank last night at a baseball field, and i couldn't get it dialed in perfectly.. the top end was either too rich and i couldn't really get on the throttle, or it would overheat and get up to about 280, when i would cover the carb with my thumb to cut it off.. dont want it to over heat..

so my question is: why is it running so hot? is it overheating? which adjustments should i make to my carb to get it running perfectly?

i'm afraid to put the shell on it as i can't see the onboard temp to see how hot it is.. as far as running it on saturday and sunday, i ran it without the shell on, as i wanted the engine to get max airflow to keep it cooler, but apparently that's not enough.. any help would be mucho appreciated! thanks

neopumpkin is offline   Reply With Quote
Old 04-14-2003, 08:55 AM   #2
Tech Prophet
Randy Caster's Avatar
R/C Tech Elite Subscriber
Join Date: Mar 2003
Location: Costa Mesa, CA
Posts: 16,675
Trader Rating: 46 (100%+)

I always tried to keep my 1/8 engines running at about 220-230 at the hottest, you are able to run them as hot as you want, but the piston/sleeve life is killed by doing so. The on board temp guages pretty much suck, they dont give an accurate reading, but are somewhere in the range of 30-40 degrees of what the actual reading is (they usually give a lower temp than you actually have) It's always hard tuning your first nitro engine, so I would suggest you go to the LHS and see if one of their expert nitro guys could lend you a helping hand, once you get the car in tune, you will have to mess with it very little, and you will get a feel for what the needles do when you are at that point. I could tell you things to try, but without bieng there, and holding the radio in my hand, it is useless, as I dont know how the car is reacting to the changes.
Randy Caster is offline   Reply With Quote
Old 04-14-2003, 07:17 PM   #3
Tech Initiate
Join Date: Mar 2003
Location: northern virginia
Posts: 24

i believe i found my problem.. i richened up the top end about a 1/4 turn (in increments) and it seems to be running much cooler now, even with the shell on.. doesn't even get above 240 F.. so i have that worked out nicely.. =)

i have another question though: now that i've run about 11 tanks through the engine, i can use my fingers to work the flywheel around and move the piston up and down the cylinder..

have i worn my engine out too soon, or should the compression eventually become a bit loose to where i can move the piston up and down the cylinder with my fingers? should the compression still be super tight to where i can't do that?

neopumpkin is offline   Reply With Quote
Old 04-16-2003, 11:29 AM   #4
Tech Initiate
Join Date: Mar 2003
Location: northern virginia
Posts: 24

bumping the post in hope for a reply..
neopumpkin is offline   Reply With Quote
Old 04-16-2003, 03:32 PM   #5
Tech Apprentice
Join Date: Dec 2002
Posts: 74

Yes the engine will lose a bit of compression after break-in. You should be able to feel the piston when it gets close to top dead center. As for temp gauges, they do not suck, I use the on board type and have had no problems (run my engines around 260). The problem comes in when it is not installed right. I have the loop between the last two fins on the heat sink(per the MIP instuctions). I have found that by putting the loop around the bottom of the heat sink at the top of the block it will give you false readings
nitro dipstick is offline   Reply With Quote
Old 04-16-2003, 04:39 PM   #6
Tech Master
Orange's Avatar
R/C Tech Elite Subscriber
Join Date: Apr 2003
Location: Chandler, AZ
Posts: 1,277

There is a great article on tuning in the latest Nitro magazine. You can pick one up at your LHS.

Sean Sanchez

A.K.A. the real Orange that got banned from Trinity site.

Ernie is a d...... you fill in the blank!!
Orange is offline   Reply With Quote
Old 04-17-2003, 12:32 PM   #7
Tech Adept
Join Date: Feb 2003
Posts: 138

what if you are running lean(running higher than 270 degrees) and you put on a really good cooling head on, which drops it to normal running temperatures. I know this doesnt correct the problem. How do you check if its running too lean?
nitrosaurus is offline   Reply With Quote
Old 04-18-2003, 09:57 AM   #8
Tech Rookie
Join Date: Apr 2003
Location: Forest Lake, MN
Posts: 6
Send a message via AIM to Conor360 Send a message via Yahoo to Conor360

When you lose compression in one run.
Conor360 is offline   Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rich? Lean? Normal? duratraxrc Nitro Off-Road 2 08-27-2008 12:41 PM
over lean when no fuel... NitroWD Onroad Nitro Engine Zone 4 03-18-2008 08:55 AM
Dead plug=too lean? keavze Onroad Nitro Engine Zone 6 11-22-2007 08:24 AM
HEN lean and LEN rich...effects? keavze Nitro On-Road 1 11-09-2007 03:58 AM
Rich and Lean. R/Cstratus48 Nitro On-Road 1 07-17-2004 10:16 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

All times are GMT -7. It is currently 06:07 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net