R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road

Reply
 
Thread Tools Search this Thread
Old 02-17-2004, 09:44 PM   #1
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default My engine dies at full throttle, any ideas?

I tightened down the whole carb of my engine and at 4 turns it hauls like I've never seen it haul before. Previously it was going incredibly slow for some reason, but it seems the carb was a bit loose, so thats solved. At full throttle though the engine like coughs almost, and then dies. I see plenty of smoke when I hit the throttle initially though. I'm thinking it is lean, but I don't know, it's at 4 turns and recommended for break in is 3. I keep the car going as fast as I can get it to go before it starts trying to die, and after a couple of passes I do the water drop test. I put a drop of water on the cooling head and it doesn't even sizzle. The drop of water will roll down inside and then it will sizzle though. Any ideas?

*edit*

I got one other problem though. With only the radio turned on, when I hit full throttle air bubbles come up into the fuel line from the carb. Is this normal? Or should I see if this happens with the engine on? Maybe it'll be different from the pressure change, but iono. WHat do you say?


Last edited by Prozak; 02-17-2004 at 09:50 PM.
Prozak is offline   Reply With Quote
Old 02-17-2004, 10:03 PM   #2
Tech Champion
 
nitrodude's Avatar
 
Join Date: Aug 2002
Location: Oxnard, CA
Posts: 5,842
Trader Rating: 5 (100%+)
Default

What engine, and in what car?
__________________
Steven Muller
AKA El Pibe RUFAST? HAHA!!!
Ronin Speed Parts
nitrodude is offline   Reply With Quote
Old 02-17-2004, 10:13 PM   #3
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

It's a .21 P4 Force engine, and the car is an Ultra Worlds GT by Ofna. The eingine I think might be from Ofna too, not sure really.
Prozak is offline   Reply With Quote
Old 02-17-2004, 10:19 PM   #4
Tech Champion
 
nitrodude's Avatar
 
Join Date: Aug 2002
Location: Oxnard, CA
Posts: 5,842
Trader Rating: 5 (100%+)
Default

Does it die after its been run at WOT, or does it die when you aply WOT.? And how does it sound, like gurgling?
__________________
Steven Muller
AKA El Pibe RUFAST? HAHA!!!
Ronin Speed Parts
nitrodude is offline   Reply With Quote
Old 02-17-2004, 10:22 PM   #5
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

I can apply WOT and it'll take off like crazy with smoke coming out, but after a second or two it'll die. And I'm not too sure of the sound to be honest. It's late 9:20 pm, so I don't want to start it up and disturb the neighbors. I'll be checking things out tommorrow morning though. I think it is gurgly though.
Prozak is offline   Reply With Quote
Old 02-17-2004, 10:28 PM   #6
Tech Champion
 
nitrodude's Avatar
 
Join Date: Aug 2002
Location: Oxnard, CA
Posts: 5,842
Trader Rating: 5 (100%+)
Default

If it takes off pretty good you are provably lean on the top end. Also check what it deos when it dies. Does it hesitate alittle bit and then dies, or does it die instantly. Its hard to tell without seen the car run, but trying to help.
__________________
Steven Muller
AKA El Pibe RUFAST? HAHA!!!
Ronin Speed Parts
nitrodude is offline   Reply With Quote
Old 02-17-2004, 10:34 PM   #7
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

It hesitates before it does. I was told in another forum it was running too rich. I have it at 4 turns, when the manual recommends 3 turns for break in. I have it high because I was initially having problems where it was heating up too much, but I think I solved that by tightening the loose carb. I run it up to the point before it starts hesitating, which is still pretty quick. After a couple of passes I do the water test, but the water doesn't sizzle.
Prozak is offline   Reply With Quote
Old 02-18-2004, 12:26 AM   #8
Tech Champion
 
nitrodude's Avatar
 
Join Date: Aug 2002
Location: Oxnard, CA
Posts: 5,842
Trader Rating: 5 (100%+)
Default

It sounds to me like its too lean on top end. Which needle are you adjusting, top end or low end?
__________________
Steven Muller
AKA El Pibe RUFAST? HAHA!!!
Ronin Speed Parts
nitrodude is offline   Reply With Quote
Old 02-18-2004, 12:40 AM   #9
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

Well I know there is a main needle, and I also know there is an idle screw(is that low end?). And then there is another needle on the side that I keep flush with the block. I mainly just move the main needle, and I keep the idle screw about 1mm closed. Would I need to adjust this needle?

And that one that is flush with the block, whats that do? I'm not sure if you know what I'm talking about though.
Prozak is offline   Reply With Quote
Old 02-18-2004, 06:11 AM   #10
Tech Initiate
 
Join Date: Nov 2003
Posts: 45
Trader Rating: 1 (100%+)
Default

Using a hotter plug might help. I had such problems before and it solved my problem. Hope it also helps yours.
cycross is offline   Reply With Quote
Old 02-18-2004, 10:37 AM   #11
Tech Elite
 
popsracer's Avatar
 
Join Date: Oct 2002
Location: "Hot, Sunny Southern California"
Posts: 3,120
Default My engine dies at full throttle, any ideas?

Prozak;

Usually the problem you describe is from a too RICH condition and or too COLD of a glow Plug.

When you pull full throttle, the cold fuel rushes in and cools down the glow plug element enough to flameout the engine. This is especially common with new engines not fully broken in yet.

As for the bubbles in the fuel line;

If you look closely the bubbles are coming FROM the Carb when you open the throttle. This is caused from the pressure differential of a warm engine and cold tank. Once the engine is running, suction from the crankcase and muffler pressure draw/push fuel to the carb.

Last edited by popsracer; 02-18-2004 at 10:45 AM.
popsracer is offline   Reply With Quote
Old 02-18-2004, 05:44 PM   #12
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

Hey, I played with the needles and I changed the glow plug so I'm not sure what the problem was, but it seems to be fixed now.

I have a question concering my glow igniter though. It sat in my garage like for 3 years or so and now the needle that tells you if the glow plug is good or not, goes barely pass the red mark. Even fully charged and using a new glow plug it won't go past that mark. So I don't know if the charger needle is broken, or the battery is no longer good on it. Do you know if they sell sub c disposable batteries? I went to walgreens and didn't see any.
Prozak is offline   Reply With Quote
Old 02-18-2004, 06:12 PM   #13
Tech Elite
 
popsracer's Avatar
 
Join Date: Oct 2002
Location: "Hot, Sunny Southern California"
Posts: 3,120
Default sub c disposable batteries

Prozak;

As far as I know, the Sub-C size is in rechargables only.

Just buy a new cell from your local Hobby Shop or Electronics Store. One or the other will surely have individual Sub-C cells for sale.

Prices will vary by type and Mah.
popsracer is offline   Reply With Quote
Old 02-18-2004, 06:58 PM   #14
Tech Initiate
 
Join Date: Jan 2004
Posts: 32
Default

Ok I'll get a new battery, will be good to have for backup too anyways. Another question though, my charger says it has an output of 1.2 volts at 170mah, and my battery says it should charge at 160 mah over 14 hours. What does that 10mah difference affect if anything? And if I get a higher mah battery, will I be able to use the same charger? Or how does this all work? Thanks.

Also, I see some batteries say 1.2 volts and others say 1.25 volts. Is there really a differece in volts? Or is it just a difference of what digits are being reported?
Prozak is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine stalls at full throttle. fastfad Rookie Zone 8 12-31-2012 06:07 PM
Hyper 7 starts but dies as soon as throttle taken up!? Saxo Boy Electric Off-Road 6 09-24-2005 09:56 AM
Engine dies after full load... megasig Rookie Zone 10 05-06-2005 06:08 AM
engine idle rpm went up instantly after full throttle?? (off the ground) US_MATRIX Onroad Nitro Engine Zone 3 01-31-2005 06:20 PM
Burned Out 2 Throttle Servos....Any Ideas?? tunerjetta29 Nitro On-Road 9 01-12-2005 07:31 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 10:03 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net