Idle issues

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enzo3856

Well-Known Member
Messages
174
Hey Guys..
Looking for some help.
Just rebuilt this rig, cleaned everything up on it.
New fuel lines, clean air filter, etc.
I reset the needles. I think the idle set screw needs to be turned in...
Anyways, in the video you can see when i peg the throttle it has a little bog. When I run it, it will bog and then take off.
Also, the motor stalls on its own as seen in the video.
Thanks in advance

 
Hey Guys..
Looking for some help.
Just rebuilt this rig, cleaned everything up on it.
New fuel lines, clean air filter, etc.
I reset the needles. I think the idle set screw needs to be turned in...
Anyways, in the video you can see when i peg the throttle it has a little bog. When I run it, it will bog and then take off.
Also, the motor stalls on its own as seen in the video.
Thanks in advance

Change the plug
 
Hey Guys..
Looking for some help.
Just rebuilt this rig, cleaned everything up on it.
New fuel lines, clean air filter, etc.
I reset the needles. I think the idle set screw needs to be turned in...
Anyways, in the video you can see when i peg the throttle it has a little bog. When I run it, it will bog and then take off.
Also, the motor stalls on its own as seen in the video.
Thanks in advance

I've been tuning nitro for a long time, thought I had the ideal methods, but after watching this vid I learned some new stuff. Long vid but well worth the knowledge


 
I'm thinking pinched gasket or loose bolt somewhere on the carb. Kinda sounds like it's sucking too much air.
I will check both the LSN and retake a look at the carb an make sure nothing is loose...
don't think it will be the gasket, I made sure everything was snug when I bolted it back on the motor. Worth a look anyways
 
I've been tuning nitro for a long time, thought I had the ideal methods, but after watching this vid I learned some new stuff. Long vid but well worth the knowledge


WTF..... What does tuning a nitro have to do with tuning a 2 stroke carb ?
index.jpg

OP was that WOT? I agree about richening the low needle . My other thought was is your clutch shot? But you weren't even getting enough rpm to engage the clutch.
 
WTF..... What does tuning a nitro have to do with tuning a 2 stroke carb ?
View attachment 73059

OP was that WOT? I agree about richening the low needle . My other thought was is your clutch shot? But you weren't even getting enough rpm to engage the clutch.
Cripes, I deserved to get female dog slapped, I was browsing the "other RC" forum and quickly jumped here and just had "nitro" engines and "idle problems" pegged in my brain.

585be7.jpg
 
Run down the list until ya find the problem.

1- Carb settings
2- Carb rebuild or new carb
3- Air filter, insulator and exhaust gaskets


https://www.largescaleforums.com/threads/carb-rebuild-and-trouble-shooting.24995/
1- I used default settings (1.5 HSN, 1 1/8 LSN)
2- stock WT 668 on a CY 26cc
3- Stock HPI filter - freshly cleaned and inner foam oiled

The clutch is fine. It is fairly new (a gallon at most through motor). There is a lot meat on it
I was just showing the bog on throttle response. If I keep the throttle on, it bogs and then takes off just fine. If it just sits there it will eventually stall.

The weather has been crappy here so I probably wont get to this until this weekend... thats also assuming I find a gap in the 'honey do' list ;-)
 
So the weather has finally been nice.
I took the car out yesterday and it lasted all of 5 minutes... It started up nicely and was running well, and then when it was warmed up it would start to bog and sound like it was starving...
So today I took the carb out, tore it apart and cleaned everything. I changed all the gaskets and put in a new plug.
Reset the needles to 1.5 HSN and 1 1/4 LSN. I increased the idle screw almost all the way in.
I can get it started but it then idles and burbles a bit and then stalls.
I noticed the grommet on the fuel tank is a little loose... could that be an issue?
again, this is a 668 Walbro, stock HPI 2 element air filter, new fuel lines, new plug, new pipe. I checked around the pipe exhaust port and it is clean and dry so no leakage on that end.
The fuel is good. I ran a whole tank of the same fuel on my other Baja.
Last run of last year it was running smoothly...
 
Im gunna say your carb is a dud. Get a new one and your problems will be solved. I had a very problematic 990 that was new and it didn't tune right. And id probably stop running that till you get a new carb otherwise your going to be replacing your top end from a lean seize.. your running way too lean

Also that grommet is the least of your worries and no it wouldn't cause an issue if anything consider it just another vent but yes just replace that with a new one
 
Is your filter or carb wet?
Nope... Filter is dry (aside from filter oil)... the was very little oil/fuel in the filter holder... a couple drops maybe
Ugg..... have you checked for air leaks? Is the metering lever set properly? Is the pulse hole free and clear? Is the diaphragm installed properly?
I checked all the holes in the carb.
I checked for the pulse hole on the carb and the gasket.
Im gunna say your carb is a dud. Get a new one and your problems will be solved. I had a very problematic 990 that was new and it didn't tune right. And id probably stop running that till you get a new carb otherwise your going to be replacing your top end from a lean seize.. your running way too lean

Also that grommet is the least of your worries and no it wouldn't cause an issue if anything consider it just another vent but yes just replace that with a new one
Thanks.
I was wondering if it was boiling down to that... I know last year already I had to turn up the idle set screw for it to hold... I also noticed playing with the low speed needle the difference is weird... Like i turn 1/4 slowly and then all of a sudden it changes... nothing gradual... just not a smooth idle at all...
I have some money in PayPal, so I will check out Dave's and see what I find.
Thanks again
 
With a CY26cc motor, should I just stick to the 668 carb?
A few options on DDM... not sure if any other than the 668 is what I need??
 
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