This ESP motor soon out the window, without opening the window first!!!

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J-Revo

J-Revo

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I still can't get this motor to run right. I have tried everyting. The problem startet with the idle screw needed to be all the way in to get it to start with the L needle at 1 1/4. As I unscrewed the idle screw I turned in the L needle.
I ended about 3 turn out at the idle screw and 1 turn out on the L needle.
This makes it run to lean. Turning in the idle screw and out the L needle makes it burn through spark plugs like a whore in the red light district!

Yesterday I had it at about 1 turn out on the L and 1 1/5 on the H.
Good idle, nice torque but it won't flat out in RPM at high speed.
It sounds like the H needle are to rich, but I can turn it almost to 1 turn out on the H, but no differense, it stil won't have clean RPM at high speed.

Maybe the L needle needs some adjusting. Maybe I will try to change the 990 carb to an earlier carb, but if that doesn't fix it I'm all out of sugestions.
 
How much gas have your run though it? Did you take time to break it in properly? If so I would get in touch with who ever you bought it from.
 
I took the time to run it in. Also followed the ESP suggested tuning guide 3 times.
The main problem seems to be that it need to much idle screw, all the way in, to make it ok to tune. I have had this problem since new, so maybe it came this way from DDM.
But I don't know what to look for to define a broken carb.
 
J-Revo said:
I took the time to run it in. Also followed the ESP suggested tuning guide 3 times.
The main problem seems to be that it need to much idle screw, all the way in, to make it ok to tune. I have had this problem since new, so maybe it came this way from DDM.
But I don't know what to look for to define a broken carb.
Click to expand...

easiest way to check if it is the carb is to replace the carb alltogether. have you checked for a possible air leak being the heart of the problem?

first check for air leaks around the carb, head and case gaskets
next try replacing the carb
also what ratio are you running
what % octane?
 
I do not like ESP so called factory settings on the carb as they are WAY to rich. Correct me if I am wrong but I think ESP recommends 2 High and 1 1/2 Low. When I broke in my 30.5 the past two weekends with the factory 1 1/2 High and 1 1/4 low it was WAY to rich so I know ESP would sure be way to rich. I had to lean my 30.5 from factory settings just to get it to start and stay running as well as to get up to temperature for proper break in.

When breaking in a motor you want it to get up to at least 170 to 180 degrees Fahrenheit or you are not getting a proper break in. I like heat cycling my new engines.

Please keep us posted on the out come and I wish you luck.
 
I exchanged some mails with ESP and DDM. They are very helpful, but I do think Doug at ESP are most comfortable with dealing over the telephone. He answers my email, but encourage me to call him every time ;) haha, as english ain't my main language I'm not very comfortable with my spoken english ;) haha

We got to the point where I got a new carb for 20 dollars, I think that is a good deal as the carb ain't covered by warranty.

Run the engine with the old carb today, and the adjustments are all over the place.
The primber bulb stays FULL of fuel, NO air bubble at all.
It had almost NO low end power and won't reach high end RPM.
To me it sounds like it's getting WAY to much fuel, but it's dangerously low adjusted.
I didn't start it out this way, I startet at H1 1/2 and L1 1/4 and took it from there, but it's the same all the way.
It almost sounds like a airleak, but I have torn the engine apart and put it back together, the gaskets are like NEW. Why wouldn't they be, I have only gotten about 1 1/2gallon trough this engine.

If a new carb don't fix it, I'm going to buy a new engine, but not ESP this time!!
 
Being it was a new engine why wouldn’t the carburetor be under warranty? When you took it apart did you replace the gaskets or least use some sealer? Did you check for air leaks with something like WD-40? Hate to hear you are having problems with a NEW engine.
 
When I changed the standard Walbro 603 (?) on my G260RC for an 813, I had to lean the fuel off, to around 1.25 / 1.1, so 1.5, 1.25 on an 813, if that's what you have, may well be too rich.
What colour is the plug - after it has run?
Is the engine bogging or even flooding?

Al.
 
Yes that was just the starting point, got close to 1 turn on both needles in the end, but no change. It's bogging on high rpm and have very little power on low rpm.
Doug had the opinion that these carbs, WT-990, could clog up in only minutes.
Maybe that's what happened, I don't know, but I will find out when the new carb arrives.
 
I have checked it for leaks, and I can't find any. Used the same method as when I fixed the lower intake manifold on my 1/1 blazer. Sprayed some wd40 around the gaskets and listened for rpm change.

It is a Zenoah 30.5 ESP, been this way from the first time I opened it up to some throttle. I didn't want another 990, and went for a 668 instead.
 
ive heard of guys opening the needles way up with the 990, as much as 2 turns on the high end. if its not making a difference leaning it out, try richening it up, see what happens.
 
I think all the new Zenoah come with the 990. I did a good bite of research on carburetors and seems the 990 is the most like carburetor as far performance carburetors go. The 668 is very user friendly. What engine where you running before you got this one?

When you checked for air leaks did you check the base gasket and look at the seal behind the fly wheel. Does this engine still have the third bearing or was it replaced with a seal? I think Doug replaces them with a seal which in my opinion is best. Some have had problems with the third bearing and air leaks.
 
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Before I got this engine I had a Zenoah 26cc. That motor had more top speed and low end power then this 30.5 ESP engine. I checked all the gaskets, but for the third bearing I must check one more time.
 
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