Beginner mods?

[Kpi890]

I have a completely stock China chick I ordered and built from Amazon and so far all has been well! I’ve got tank and a half of 16:1 through her already mixing Maxima pro scooter oil. What I’m wondering is right now what am I able to do easily to improve this engine/system to get a little more out of it? I bought a NGK iridium BPR6HIX because I saw a few other posts saying that may improve some things a little bit but I’m not sure. As of right now the top speed maxes out at about 26mph on a flat level surface. I have yet to put the new spark plug in there so just looking for any simple mods that may improve the low end or WOT of this engine without spending a whole lot of money. Thanks!

 

[6blueoval9]

The NGK plug may or may not be an improvement...Plug choice as far as heat range should be determined based on your particular climate...being an iridium plug can be a plus but more so with longevity of the plug.

I would consider you tune the motor to it's best ability before doing anything to it...Simply adding bolts on don't mean you'll get all that much more from your motor.

In all honesty, a little bit of Dremel tool work can do far more to improve performance than many bolt ons will.

Just a simple cleaning of the cylinder ports casting flash is a great start...you really only need a simple file to do this with...How big of a gain in performance will determine how bad the cylinders were to begin with.

Don't get caught up in bolt ons and learn more on how to improve what you already have..once that is done bolt ons can be a more dramatic improvement and more worth the money.

If you just want a simple answer with what to buy then I would recommend the following.

1.) Upgraded air filter.$10
2.) Jetting kit for your carburetor to tune properly.$15-$20
3.) NGK plug wire, boot and, plug upgrade.$15-$20 minus plug.
4.) OZ super magneto.$13-$15

These are about the least expensive upgrades you can do that should make a difference on a bone stock motor...An upgrade exhaust is a big help but I would save that for last.

If you can do some Dremel work, depending on what intake manifold you have I would add an upgrade carburetor to the list.

If you have the aluminum intake manifold, bore the inlet out to 16mm and pick up the "speed" version of your stock NT carburetor. $20

Or, if you have the steel manifold then you shouldn't need to do any work on it but still pick up the speed carburetor. $20

Prices are ball park figures or maybe an average price which may or may not include shipping....shop around.

 

[Kpi890]

The NGK plug may or may not be an improvement...Plug choice as far as heat range should be determined based on your particular climate...being an iridium plug can be a plus but more so with longevity of the plug.

I would consider you tune the motor to it's best ability before doing anything to it...Simply adding bolts on don't mean you'll get all that much more from your motor.

In all honesty, a little bit of Dremel tool work can do far more to improve performance than many bolt ons will.

Just a simple cleaning of the cylinder ports casting flash is a great start...you really only need a simple file to do this with...How big of a gain in performance will determine how bad the cylinders were to begin with.

Don't get caught up in bolt ons and learn more on how to improve what you already have..once that is done bolt ons can be a more dramatic improvement and more worth the money.

If you just want a simple answer with what to buy then I would recommend the following.

1.) Upgraded air filter.$10
2.) Jetting kit for your carburetor to tune properly.$15-$20
3.) NGK plug wire, boot and, plug upgrade.$15-$20
4.) OZ super magneto.$13-$15

These are about the least expensive upgrades you can do that should make a difference on a stock motor.

If you can do some Dremel work, depending on what intake manifold you have I would add an upgrade carburetor to the list.

If you have the aluminum intake manifold, bore the inlet out to 16mm and pick up the "speed" version of your stock NT carburetor. $20

Or, if you have the steel manifold then you shouldn't need to do any work on it and still pick up the speed carburetor. $20

Prices are ball park figures or maybe an average price which may or may not include shipping.

The carburetor on my current setup has “speed” cast into the metal if that’s what you’re talking about? And which air filter do you recommend? And yea this is kinda what I was looking for right now not spending money on new parts but trying to tune/modify the engine right now to get the most out of it before I add any other parts. I’m just nervous about trying out jetting it because it’s only had a tank and a half through it and I don’t want to accidentally run it too lean and burn it all up! And when you talk about boring the intake manifold are you talking about the offset pipe that leads to the carb or the actual port going into the cylinder to 16mm?

 

[Kpi890]

Also I have seen people on here remove the end cap of the stock exhaust and leave it off claiming they get a bit more low end power... is this true? If I were to do that do I need to change the richness of the e clip on the carb to accommodate for more air moving through the exhaust? Or will this cause issues such as not having enough back pressure?

 

[6blueoval9]

The carburetor on my current setup has “speed” cast into the metal if that’s what you’re talking about? And which air filter do you recommend? And yea this is kinda what I was looking for right now not spending money on new parts but trying to tune/modify the engine right now to get the most out of it before I add any other parts. I’m just nervous about trying out jetting it because it’s only had a tank and a half through it and I don’t want to accidentally run it too lean and burn it all up! And when you talk about boring the intake manifold are you talking about the offset pipe that leads to the carb or the actual port going into the cylinder to 16mm?

Yea, the speed carburetor is a 16mm version of the stock 14mm carburetor.

If you have the aluminum intake it's not really going to be much of an upgrade however as the inlet tube is only 13.5mm so that's why I say it should be bored out.

I'm talking about the inlet tube your carburetor attaches to...not the cylinder where the manifold bolts on to...only the tube part..not the opening on the other end of the manifold.

 

[6blueoval9]

Removing the end cap will make it quite loud and it's not really going to do much to help with back pressure... some claim more top end some claim a loss.

If you want to gain more from an exhaust I would try the new Zeda66 pipe you can get for less than $40...I haven't tried it yet personally but it's said to be designed for such a motor as yours with mild hop ups.

 

[6blueoval9]

And yes it's possible the tuning will be different with more air flow and a better exhaust...more air in needs more fuel in so I'm sure the tune would be different.

Rather it's at the needle or the jet only you'll have to determine.

 

[6blueoval9]

Porting at the cylinder and what is called port matching is a different ball game so be sure to ask around before diving in on that..it's too easy to destroy a cylinder and actually lose performance.

 

[6blueoval9]

I suggest finish breaking in your motor before doing anything and at this point you want the carburetor on the rich side for now.

 

[FurryOnTheInside]

Your engine is still in the break-in stage, so I wouldn't expect it to be running at full power yet. You're using (more than) break-in gas/oil ratio, and your carb is presumably still mixing the fuel/air very rich which is fine for break-in stage.

I'm sure I have told you this before, but my photo album shows mostly the really cheap and easy "coffee table" (no machine shop) mods for the basic cheapo generic no-name engines.
You can modify the engine, mostly with small, hand held, inexpensive tools and get quite a bit more out of it. If you're going to do cylinder work or balancing, you should probably get that done before you finish break-in.
You should try retarding the timing at the magnet key, as this is a very cheap modification that is totally reversible.