R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 06-28-2004, 10:28 PM   #16
Tech Elite
 
AMGRacer's Avatar
 
Join Date: Oct 2001
Location: Brisbane, Australia
Posts: 3,939
Default

Quote:
Originally posted by rodneybarrett
AMG,

I do appreciate the help.

However, I have tuned several other engines (MT12's , Rossi's, etc.) without problem so I have a pretty good idea of what is going on.

*snip*

Sorry to ramble but I cannot for the life of me figure out how to correct my problems.
No worries man. Reason I am so insistent is that I dont know you or know how much you know about tuning or how patient you are. Now I know thanks! You are doing everything totally right from the sounds of your post. I had a motor that did exactly what yours is sounding like.

It was caused by a fault in the carb. I would pull your carb completely down and check all the o rings for tears or shrinkage. They can actualyl shrink and not seal properly, this is what happened to mine and it was a very new engine. Also check the carb is seated properly, sealed and tight onto the engine.

If your car is mechanically right (sounds like it is) and your tune is good (also sounds like it is) then a fuel system leak is unlikely (since it is only on this motor). I would start with a carb checkover.
AMGRacer is offline   Reply With Quote
Old 06-28-2004, 10:28 PM   #17
Tech Elite
 
AMGRacer's Avatar
 
Join Date: Oct 2001
Location: Brisbane, Australia
Posts: 3,939
Default

Quote:
Originally posted by Johnnytc3
I think you have a carb problem. Tuning an engine with a bad carb is like ... well you know. Take your MT12 carb and swap it over and retune, i think it will solve your problems.
Precicely. Sorry man I did not read your post before I posted
AMGRacer is offline   Reply With Quote
Old 06-28-2004, 10:32 PM   #18
Tech Elite
 
GrandeGixxer's Avatar
 
Join Date: Jun 2004
Location: Waldorf, MD
Posts: 2,925
Trader Rating: 15 (100%+)
Default

sounds to me like you either have an air leak, a bad plug, or too lean on the bottom. to test for an air leak, start engine spray denatured alcohol around the carb, and if it dies, you have an air leak somewhere.
GrandeGixxer is offline   Reply With Quote
Old 06-29-2004, 08:21 AM   #19
Tech Fanatic
 
Join Date: Aug 2001
Location: Nashville, TN
Posts: 852
Trader Rating: 49 (100%+)
Default

thanks for the posts.


I pulled the carb apart last night and found something interesting. The banjo fitting (the black plastic thing) did not seem to have the hole go totally through it. What I mean is that at the end where the circle is, it looked like some flashing was still on there and the hole was only open about 60%. I took a drill bit the same size as the hole and cleaned out the flashing. All the o-rings looked good.


Could this cause the problems I have been having?

I am still going to try my mt12 carb on it to see if it helps.

Also, I'm still on this whole filled crank issue. For some reason, I can't let it go. I just think that the difference in volume has to have some kind of effect on the engine. Attached is a picture of how the crank is suppose to be. When I get home tonight, I'll take a picture of my crank so you can compare
rodneybarrett is offline   Reply With Quote
Old 06-29-2004, 06:43 PM   #20
Tech Elite
 
AMGRacer's Avatar
 
Join Date: Oct 2001
Location: Brisbane, Australia
Posts: 3,939
Default

Quote:
Originally posted by rodneybarrett
thanks for the posts.


I pulled the carb apart last night and found something interesting. The banjo fitting (the black plastic thing) did not seem to have the hole go totally through it. What I mean is that at the end where the circle is, it looked like some flashing was still on there and the hole was only open about 60%. I took a drill bit the same size as the hole and cleaned out the flashing. All the o-rings looked good.


Could this cause the problems I have been having?

I am still going to try my mt12 carb on it to see if it helps.

Also, I'm still on this whole filled crank issue. For some reason, I can't let it go. I just think that the difference in volume has to have some kind of effect on the engine. Attached is a picture of how the crank is suppose to be. When I get home tonight, I'll take a picture of my crank so you can compare
I think you have found your problem.

For the crank, I have run a crank exactly like the one you are describing (lightened by boring it) with no fill and the motor hammered until I popped a rod on it one day. It had 27 litres of fuel through it. I cant see it hurting your engine. Anyways if you are not happy return the crank for a filled replacement.
AMGRacer is offline   Reply With Quote
Old 07-02-2004, 04:58 AM   #21
Tech Master
 
BrainTeased's Avatar
 
Join Date: Jan 2004
Location: Melbourne
Posts: 1,342
Trader Rating: 4 (100%+)
Default

Quote:
Originally posted by AMGRacer
I think you have found your problem.

It had 27 litres of fuel through it. I cant see it hurting your engine.
Hey AMG what engine is this your talking about? 27 Litres!!! also guys does engine flame out mean engine stalling? i always thought engine flame out was something to do with flames lol!
__________________
www.feralbatteries.com.au
BrainTeased is offline   Reply With Quote
Old 07-02-2004, 03:47 PM   #22
Tech Rookie
 
Join Date: Sep 2003
Posts: 2
Default

I have experienced similar problems with a few other motors. If driving the car and being alot more aggressive on the throttle, the car did not stall, but slowly increasing throttle just killed the car mid way on the track. Try this. With the wheels off the ground, slowly increase rpm of the engine to the point where it is usually dying on the track. Hold the throttle at that point and see if the engine dies again. What I have found was the needle in the carb was at the point where it was just out of the metering tube, thus causing a high flow of fuel. I had adjusted the mid range needle to move the transition point where it wouldnt die as easily. I also found that using a different pipe helped.
fastrax is offline   Reply With Quote
Old 07-04-2004, 03:54 PM   #23
Tech Elite
 
AMGRacer's Avatar
 
Join Date: Oct 2001
Location: Brisbane, Australia
Posts: 3,939
Default

Quote:
Originally posted by BrainTeased
Hey AMG what engine is this your talking about? 27 Litres!!! also guys does engine flame out mean engine stalling? i always thought engine flame out was something to do with flames lol!
It was a RB X12 motor. Awesome motor for its time.
AMGRacer is offline   Reply With Quote
Old 07-04-2004, 09:24 PM   #24
Tech Master
 
Z00M's Avatar
 
Join Date: Jun 2004
Location: Perth, Western Australia
Posts: 1,173
Trader Rating: 15 (100%+)
Default

If none of the advice regarding issues with the carb helps, then it can actually be a result of the mods done to the engine.

I was reading on the RB MODS website about some of the history, and he/they(?) actually introduced a harmonic into the air pulses within the motor that would cause the engine to stall at a particular RPM. This was created by presseure waves rebounding on themselves in order to completely stop the fuel supply within the sleeve area.

I wouldn't suggest this is your problem until all other avenues of checking for problems and air leaks within your engine are exhausted, especially if the mods are done by a reputable supplier. They too would have worked all of this out by now.

Cheers,

Mike.
Z00M is offline   Reply With Quote
Old 07-04-2004, 09:37 PM   #25
Tech Fanatic
 
Join Date: Aug 2001
Location: Nashville, TN
Posts: 852
Trader Rating: 49 (100%+)
Default

Interesting. The TOP TSR12S3 is modified at the factory per Jim Hottinger (spelling?) of Fusion Motor sports. I sure hope this isn't the problem.


I ran it a couple of days ago testing it out and it still died twice on me but did seem to run better. I just chalked it up to the fact that it is a modified engine and that the needles are more touchy than a stock P/S.


I have an email into Jim but he has not replied (been about a week or so). Hope he's not avoiding me.
rodneybarrett is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
flame out kj racing Nitro Off-Road 6 08-18-2008 05:40 AM
Hissing jet of flame from my XBR macnkitty2002 Electric On-Road 36 09-24-2007 05:10 PM
Flywheel/Engine issues with FWO5T(GXR15) scuby_snax84 Rookie Zone 2 07-29-2007 05:35 PM
Engine Issues NitroOB4You Nitro On-Road 23 08-25-2002 11:29 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 08:51 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