How to tune my new engine without damaging it!?

[ChuenouXiao]

How would you pros out there tune your XB engine? I understanding running lean is not good comparing to running rich. Any tips to prevent a bad engine? Even though I don't think it's me. I have a basic understanding of how to tune the engine. What is the safest way to tune a engine?

 

[Deluge]

Lean it out a little at a time. About a 16th of a turn. You want to creep up to your final setting. When you find your final setting, richen it a little. This will insure you have enough lube flowing through the engine. Also, read your spark plug while you tune. To do this, do a high speed run and kill the engine before it has time to load up on fuel. This will give you an accurate reading. Here's some info that'll help with reading the spark plug.

Spark Plugs

 

[ChuenouXiao]

Lean it out a little at a time. About a 16th of a turn. You want to creep up to your final setting. When you find your final setting, richen it a little. This will insure you have enough lube flowing through the engine. Also, read your spark plug while you tune. To do this, do a high speed run and kill the engine before it has time to load up on fuel. This will give you an accurate reading. Here's some info that'll help with reading the spark plug.Spark Plugs

Very nice reference.... high speed run and kill the engine? Turn it off right after a high speed run when the engine is hot? Take it out and check the spark plug and comparing it to spark plug reading?

 

[RampageHopUps]

Nitro tuning video deleted.

 

[ChuenouXiao]

Nitro tuning video deleted.

What do you mean deleted? You deleted the link? Just wondering

 

[RampageHopUps]

Like, made it go away so people don;t get the wrong information.

 

[ChuenouXiao]

Like, made it go away so people don;t get the wrong information.

Well... I followed this video to tune my engine and adjust my idle accordingly. Priority by number listed:

1. idle screw (adjust it to start engine and stable idle)

2. low speed needle for good idle (adjust a little here and there but very little for good low end performance)

3. high speed needle, lean until top speed is reach and then i rich a quarter or a quarter and a half from the top speed setting of HSN. (use gps to clock top speed)

I don't see how this good damage the engine? Unless I'm doing something wrong. Of course I always add oil with the proper mixture. Let me know..... thanks....

[ame]http://www.youtube.com/watch?v=jewDW3G4LKg[/ame]

Of course every engine is different... depending on the setup and other factors.... but you have to find the best tune for your engine without running too lean right?

 

[Guest]

That sounds to be on the rich side. You should have been safe. A quarter plus turn would be much richer.

 

[ChuenouXiao]

That sounds to be on the rich side. You should have been safe. A quarter plus turn would be much richer.

So do you think I'm running too rich? Or the way I tune it, is it alright?

 

[ChuenouXiao]

Lean it out a little at a time. About a 16th of a turn. You want to creep up to your final setting. When you find your final setting, richen it a little. This will insure you have enough lube flowing through the engine. Also, read your spark plug while you tune. To do this, do a high speed run and kill the engine before it has time to load up on fuel. This will give you an accurate reading. Here's some info that'll help with reading the spark plug.Spark Plugs

You know Deluge, you make alot of sense... and that's exactly what I did to my engine besides spark plug reading. Don't know how the way I tune it could damage my engine?

 

[Guest]

The only thing you can hurt from being too rich is the performance and spark plug fouling. When you run rich you have more lubrication and the unburnt fuel helps cool the engine. The goal is to find the happy medium. The spark plug check is great. I also use a laser temp gun on mine. Here in AZ it is easy to get too hot. The leaner you go the hotter it runs. I try to not get too much over 200 deg.

 

[ChuenouXiao]

The only thing you can hurt from being too rich is the performance and spark plug fouling. When you run rich you have more lubrication and the unburnt fuel helps cool the engine. The goal is to find the happy medium. The spark plug check is great. I also use a laser temp gun on mine. Here in AZ it is easy to get too hot. The leaner you go the hotter it runs. I try to not get too much over 200 deg.

Yes.... I agree.... I have a laser gun too but gave it away when I gave my nitro away. Going to buy me another one for my 1/5 scale. Which one is the best that you know of?

 

[Guest]

I use a cheap one I bought from harbor freight. I works just fine. I think it was on sale for like 29 bucks or something.

 

[ChuenouXiao]

I use a cheap one I bought from harbor freight. I works just fine. I think it was on sale for like 29 bucks or something.

Do you know if these engines are design to not start when they are too hot? I assume they are?

 

[Deluge]

Some people tune by ear, and some people tune by reading the spark plug. I've always tuned by reading the spark plug. The plug will show if you're running too rich, or too lean. The link I provided in the first post shows the differences between lean, rich and what you want to aim for. If you want clarification on tuning procedures, everyone has a different angle on it. Here are a few examples.

New carb tuning instructions, ESP

My Carb and Me. How your Carb works and Tuning Guide

Scroll down to "How should I adjust the jets on a Walbro Carburetor (WA-167 / WT-603 / WT-668 / WT-257 / WT-813, etc)?"

 

[ChuenouXiao]

Some people tune by ear, and some people tune by reading the spark plug. I've always tuned by reading the spark plug. The plug will show if you're running too rich, or too lean. The link I provided in the first post shows the differences between lean, rich and what you want to aim for. If you want clarification on tuning procedures, everyone has a different angle on it. Here are a few examples.New carb tuning instructions, ESP

My Carb and Me. How your Carb works and Tuning Guide

Scroll down to "How should I adjust the jets on a Walbro Carburetor (WA-167 / WT-603 / WT-668 / WT-257 / WT-813, etc)?"

The tune by spark plug make a lot of sense because it's the spark plug giving you feedback of your engine's performance wither its too hot or too cool.... I like the spark plug reading.....

 

[Guest]

Do you know if these engines are design to not start when they are too hot? I assume they are?

There is no temp failsafe. If it won't start because of over temp it might be too late

 

[ChuenouXiao]

There is no temp failsafe. If it won't start because of over temp it might be too late

So base on my understanding, better to run rich then lean and tune for great performance but to where the engine is properly cooled also... ? Quite complicated but seems like you always have to double check needle to maintain sweet spot for proper engine cooling and for it to not seize. Oh... and read your spark plug

 

[ImminentFailure]

What was your break in procedure? A lot of this fine tuning is after you break it in, and you are 'tuning' in the engine for its sweet spot. Before that you have break in, which I usually go about 5 tanks on for the overall procedure. I do all this while on the rich+ side. There's several threads already about that key first two tanks. Some just run it, some treat it like nitro with little 1/4 on / off throttle figure eights. Can read up on them. Getting a stock CY/HY is recommended if this is your first 2 stroke RC.

Also, what ratio oil/gas are you running? Is it synthetic or no? Every poll you read on HPI baja forums and such is 25:1.

 

[ChuenouXiao]

What was your break in procedure? A lot of this fine tuning is after you break it in, and you are 'tuning' in the engine for its sweet spot. Before that you have break in, which I usually go about 5 tanks on for the overall procedure. I do all this while on the rich+ side. There's several threads already about that key first two tanks. Some just run it, some treat it like nitro with little 1/4 on / off throttle figure eights. Can read up on them. Getting a stock CY/HY is recommended if this is your first 2 stroke RC. Also, what ratio oil/gas are you running? Is it synthetic or no? Every poll you read on HPI baja forums and such is 25:1.

I break in 1 full tank with my XB elevated. I vary my throttle a little every 5 min but never full throttle. My mixture is 25:1 and I'm running synthetic oil.