Engine bogs down at WOT!

RTR3racer · #1 09-29-2002, 02:29 PM

Hey guys. I just finished breaking in my HB .12 engine. But now i've run into some problems. First off. When i lean out my high speed needle, at WOT the engine seems to bog down and die. Should i richen my low speed needle or lean it out also to compensate for the leaned high speed? I'm not really sure what to do. If anyone can give me some advice that would be great. Thanks guys.

-=ADA$=- · #2 09-29-2002, 02:35 PM

i think you should do couple of speed runs, and lean/richen high sped needle, and after its perfectly tuned, tune low speed needle

Tstalion79 · #3 09-29-2002, 02:57 PM

Lean out the top end a good 1/2 turn, and richen the bottom end about 1/4 turn to compensate for the leaning of the top end. I almost guarantee that this will fix the problem. Your problem right now is fuel build up. This will be fixed by 1/2 turn lean on the top end.

carerra · #4 09-29-2002, 05:56 PM

Quote:

Originally posted by RTR3racer
Hey guys. I just finished breaking in my HB .12 engine. But now i've run into some problems. First off. When i lean out my high speed needle, at WOT the engine seems to bog down and die. Should i richen my low speed needle or lean it out also to compensate for the leaned high speed? I'm not really sure what to do. If anyone can give me some advice that would be great. Thanks guys.

could be because it's running too lean...if your gonna do WOT it's best run a bit richer to provide better engine lubrication and to allow more fuel into the engine when it's going at 40,000rpm....if you have it too lean then the engine's just gonna starve at high reves as to little fuel and oil is getting in.

Tstalion79 · #5 09-29-2002, 06:39 PM

That would not cause "bogging down". That would cause flameout. Bogging down is due to the mixture being too rich and fuel is building up in hte engine.

RTR3racer · #6 09-29-2002, 07:38 PM

Thanks for all the replies guys. I'm gonna try what Tstalion79
said. That seems to make the most sense. Because when i floor the trigger it starts to bog down and die. Thanks again for the replies.

Tstalion79 · #7 09-29-2002, 08:30 PM

No problem. I guarantee you that i am right!

Stalker911 · #8 09-29-2002, 09:34 PM

Not to start anything here... but since you told him to lean it out even more.. and you garanteed that was the solution... are you going to buy him another motor when he pops that one cause it is too lean??

It's almost impossible to diagnose a problem with out ALOT more details then that...

Here is my sure fire way to get everything figured out... RICHEN THE HELL OUT OF IT. Then lean down from there. The reason I say this is because I had a motor that acted like it was bogging, but in reality it was actually starving for fuel, just not quite enough to flame out.

My first impression of your problem (before I even got down past your pist) was that you were too lean. A motor starving for fuel and just barely staying running can sound almost the same as one bogging... but if there is a TON of smoke comming out when it bogs then yea it is bogging... if not... then it could be too lean...

When I broke in my Hyper 21 (as per OFNA instructions) it was too lean. Put it this way... my running settings now.. are richer than what they said to break it in. When I was done (as per their instructions) I was WAY lean! The motor wouldn't even rin right. Now I am over 2 turns richer on the high end and 1.5 on the low end (from first run settings) and the motor has tons of go power! Richer is not always less power...

Tstalion79 · #9 09-29-2002, 09:43 PM

I see your point Stalker, but seeing as he "just finished breaking in his engine", obviously under rich conditions, he is probably still in the rich side of things. Also, at WOT, an engine that is "too lean" will not bog down. It will at half throttle, but not at wot because the remaining fuel will burn almost instantly. His problem is having too much fuel in the chamber to burn. I seriously know what i am doing man.

Sammy · #10 09-30-2002, 03:38 AM

Quote:

Originally posted by Stalker911
The reason I say this is because I had a motor that acted like it was bogging, but in reality it was actually starving for fuel, just not quite enough to flame out.

Can someone please provide me with a decent description of "flameout", ie. symptoms?

Einsteindks · #11 09-30-2002, 04:48 AM

Flameout is simply when the engine stops running 'cause of a fluke, glitch, or significant jolt in the normal operation that lets the glowplug to dim beyond the point of normal heat/brightness to ignite the fuel. It stays lit as a result of the heat from the combustion process.

Crashbot2001 · #12 09-30-2002, 07:58 AM

My truck was doing the exact same thing this weekend at the race. It would run fine until it was well warmed up.. Then it would surface.. Bogging at WOT. The high end was too lean.. Richened it up 1/8 and it was better.. Another 1/8 and it was running like a champ.

Madmann135 · #13 09-30-2002, 10:31 AM

I have had many engine problems. 99.9% were due to improber tuning.

If the engine bogs than it is too rich lean it up gradually.

If the engine screams and dies it is too lean richen it up fast and go from there.

The best way to find out what's wrong is to make mistakes and learn from them.

My only problem is tuning for racing. I'm a basher and I want the best basher fuel with too much oil. I want my engine to be lean run fast and hard and not overheat (past 300F is what I call overheating).

rocknbil · #14 09-30-2002, 01:22 PM

Well I am hardly an expert but pretty much new to nitro ( two GT's for about 6 mos now) and had a terrible time getting tuned in, understanding the lean/rich/temperature algorhythms, and cannot cound the times I nearly turned my GT into an aircraft.

What I found out was this:

I had the same bog-down problems and didn't KNOW if it was rich or lean. I DID know, however, that a LEAN engine was going to be hot. So after a GOOD warmup of 10 laps or so (if it din't die before then!) I'd run it up at WOT down the straight and if it died I'd run over to it with the temp gauge. If it was over 230 I enriched it. If it was under, I leaned it. Either by only a click or two (5 °)

My only point is that in my inexperience and learning, I have seen both. Both my wife and I have GT's with OS .12 CV's and we've managed to get them to stay running as long as the tank is full and between 190 ° and 230 °.

Stalker911 · #15 09-30-2002, 10:34 PM

Tstalion79: I do belive that you know what you are doing, not trying to knock that. Just saying, I wouldn't make any garantees

Madmann135: What type of motor are you running?? 300 is WAY HOT for most motors!

Tstalion79 · #16 10-01-2002, 07:21 AM

Yeah, you never want to be anywhere over 240 or so

Madmann135 · #17 10-01-2002, 11:42 AM

Quote:

Originally posted by Stalker911

Madmann135: What type of motor are you running?? 300 is WAY HOT for most motors!

I said If My engines go over 300f That woiuld be considered overheating.

I normally run my .21 race engine (the one I want to keep) around 220f and my bash engine (the one I want to destroy but the D@mn thing won't die

) between anywhere from 220f-270f.

For my .15 engine my race one I try to keep it below 250F and above 200f that is my new engine. My old engine I would run it where I would get my maximum preformance. I don't check the tempture on that one.

My engines I want to keep are
OS .15 CV-RX
and RB products S7

My engines I don't care for are (these engines I virtually got for free)
Duratrax torq .21 (ported)
Tower .15BB (heavy ported)

purplerides · #18 10-01-2002, 12:32 PM

sounds to me like he's lean , a hot lean motor will bog at wot as it's starving for fuel, whenever you run into a tuning problem always richen it up and tune from rich towards lean.

carerra · #19 10-01-2002, 02:26 PM

Quote:

Originally posted by purplerides
sounds to me like he's lean , a hot lean motor will bog at wot as it's starving for fuel, whenever you run into a tuning problem always richen it up and tune from rich towards lean.

....and if ya run too lean your gonna seriously damage the engine due to lack of oil lubication....