?? Do performance Cdi's and h.o. coils help ??

[rebellinredneck]

I have a gs moon 150cc buggy. It uses a dc fired cdi, i was wandering if the a performance cdi and h.o. coil would help the overall performance. Here is a list of what I've done so far. Opened up the exhaust to around 1.5 inch, I'm running a spectre pod filter with 3 inch outlet, koso clutch and variator with the stock main spring and 10 gram rollers.

[xlint89]

Personally, mine starts easier and runs smoother with both installed.

[rebellinredneck]

@xlint89 I was sure the ac ones are worth it because they advance the timing at a certain rpm, but the dc don't say they do. Have you saw the efi kit for small engines, i hope to try it out sometime, some company out of Canada sells it for around $300.

[bear]

I'd like to see someone come up with a carb that works even when your buggy is at some wild and twisted angle, like they have for the rock crawlers! It would insure you had supply, but not overload it.

[SLESTAK75]

250 Ninja with carburetor smokes Honda CBR 250 with EFI.......

http://www.google.com/url?sa=t&rct=j...,d.dmQ&cad=rja

[300cpilot]

The fancy rock crawlers I have seen us propane instead of gas so they would work in all angles, including upside down.

The CDI's that I have used do work. But it is the little things they help on, like hot starts, cold starts and the starts that don't make you walk to the truck!

[SYCARMS]

A cdi has several functions. From signals it receives from the trigger switch it tells the coil when to discharge its spark and for how long, adjusts timming and controls rpm's. This is called a map. A performance cdi does the same but with a different map. Your stock cdi advances timming just as the perf cdi does. The perf cdi just uses a different map for where and how much timming is used. There is only so much timming built into our engines so to say this cdi will advance timming more then stock is not correct. All the perf cdi does is apply the timming at different points as mapped. Todays stock engines will see very little if any bennefit from a performance cdi. Many have been sold that a no rev cdi will unleash all kinds of power, another falsehood. The stock GY6 powerband limit is around 7400 rpm . The stock cdi rev limit is 7800rpm. The engine has peaked the powerband at 7400rpm so pushing the engine above that rpm range only aids in premature wear and overheating of the engine. So is a cdi and hot coil an unnecessary item? When this engine was designed its components were designed for top efficiency. Now when one starts to mod an engine making it capable to suck more air and fuel then you will need an upgraded ignition system to aid in efficiently burning the added mixture. Also depending on how you build your engine will determine your power curve, and may require a cdi with a higher rev limit. The coil is the same thing. Stock coils are designed around a stock engine and work efficiently. Building your motor is the only way to make more power. True you will gain power by removing restrictions such in the air box and exhaust plus a rejet but these will be minimal gains at best but still a felt power increase. After that one has to build the engine so as to pull in and fill the cylinder more completely with a/f mixture, this is the time you will need to upgrade the ignition, for now you will need a stronger and longer spark to efficiently burn more fuel for more power. Now so I don't contradict myself, this hasn't always been the case for when these buggies first come to market the Chinese had taken a 125cc engine and made it into a 150cc engine plus they put them in a vehicle 200lbs. heavier then the scooters they were designed for. Since that time the epa has regulated the emissions which forced the chinese to use improved electrical designs more suited for the heavier buggy which was the main reason for going to the DC volt systems over the old AC volt systems.

[bear]

I swear, sometimes it's like lokking into an encyclopedia!!! wish I where so well informed on these little buggy's!!! kudos Tom

[rebellinredneck]

Tom you always amaze me with tour answers and replies. Sounds to me like it may be time for me to make the change. I pulled the plug to read it last night and it was black and oily, so i put the iridium one in, so maybe this mod will help me burn the fuel more efficiently. Thanks for all the input. Now the question is what brand. Kidnme has a dc cdi and h.o. coil for $70. My first choice is usually Tom Syc but his site dont list a dc coil correct me if I'm wrong.

[SYCARMS]

Black and oily indicates oil consumption. A rich mix would be black and chaulky and would be due to too rich mixture caused by inop choke, stuck float, leaky needle va;lve or too rich jetting. CDI and coil will not correct the problem.

[rebellinredneck]

What could be my issue?

[SYCARMS]

If your plug has oil on it it's due to either crankcase vent is plugged or oil is getting past worn rings.

[rebellinredneck]

I'll check the crankcase vent asap. Do you stock rings, how do i know what size rings i need, how do you change them, how hard is it.

[rebellinredneck]

With the engine off i can't suck or blow thru it. With it idleing air comes out and it has a gas smell to it. The crankcase vent is the vent off the valve cover right.

[SLESTAK75]

That's right. If you feel air flow when idling then it is working. Rev the engine up some and make sure the flow from the vent increases with the rpms.

[rebellinredneck]

Sounds like rings worn rings may be my issue then, how hard are they to change and how much. Other than size are they all the same.

[SYCARMS]

You should not have a fuel smell, this tells you your getting too much fuel and it could have washed the rings. Pull the dip stick and smell the oil, if it has a fuel to it then you will have to drain and put fresh oil in. But your going to have to find the problem of too much fuel, or the same will happen. Is the choke working, is the needle leaking , is float to high or stuck.

[SLESTAK75]

2nd that. I flooded a carb in my old trans am once and a lot of fuel washed passed my rings and into the oil. It wouldn't even run until I changed the oil. Once the fuel gets into the oil the rings will stop sealing and the oil will continue to blow by and fuel will continue washing down into the oil. When I changed my oil I also put about a teaspoon of oil into the cylinder as well to help reseal the top of the cylinder.

[rebellinredneck]

When i first got the buggy i changed the oil and put a full quart in it and had a bunch of blow by it completely soaked my air filter. I changed it again with synthetic, put in the correct amount of oil that was about 6 months ago. Could that still be showing up on my plug. The buggy actually runs great, starts easy, idles great, and top speed is around 37 mph, it also climbs pretty good too. I looked at the plug again and it does kinda look chalky on the end where it sparks at.

[SLESTAK75]

A new plug would tell for sure. If it gets oil soaked. Probably bad rings. Still smell the oil on the dipstick and see if it smells like gas. Either way an oil change is advised. Tom can help you out on the rings. You will need a gasket set and rings. Remove valve cover head and cylinder. Remove piston pin and piston. Replace rings making sure the groove they go in is cleaned out. Look inside cylinder for obvious damage. It would be a good idea to hone the cylinder wall. You get a honer from auto parts store. It hooks into a drill and then run it up and down the cylinder wall till all looks even.