Turbo ATC200X... Go-Kart

[ARJ0019]

I'm a new member here. If you would like to read a bit about me, my intro post is here (http://www.3wheelerworld.com/showthr...t-you-expected).

As stated in the post above, I am building a Turbo 85' ATC200x Go-Kart; the engine received a complete rebuild, race cam, high-comp piston, and yes... a turbo. Don't bother warning of the knock that will most definitely occur without using an ECU, I'm well aware of it. I really want to try running a CDI system. Even if the CDI ends up needing to be replaced with an ECU, I just want to try it. So I'm here to ask for any advice you have in designing a custom CDI wiring harness. Below are a few things I am a bit fuzzy on and I know I could use some guidance with, but feel free to post anything you feel will be helpful to know.

1) From what I have read there are a few different versions of alternators used on small engines like these. Each has slightly different working principles, and hence a slightly different implementation. Is this true? If it is, how do I know what I have?

2) I need to run a fuel pump (I'm aware of problems with the turbo pressure, I am using the turbo to pressurize the fuel tank and equalize the carb to inlet air pressure. The pump is for lifting the fuel to the carb, and a few extra psi to pressurize it over the inlet air pressure). Unless my alternator magically outputs DC then I need a regulator/rectifier. What regulator/rectifier would you suggest buying? Is this dependent on my alternator?

3) What CDI box would you recommend? Are there features of my 85' ATC200X engine that affect which CDI I can use? Is something like a programmable MSI CDI box really worth the money?

4) I would like to run a battery so that I can prime the pump, but I have work around depending on the pros/cons of implementing a battery. What are some possibly unknown pros/cons of running/not running a battery? Would you recommend using a battery in my circuit? What battery would you recommend?

As an additional note, being able to find all the components for this wiring harness in a single kit would be a huge plus. If your aware of any good full CDI kits, please let me know. Thanks for any help you can provide.

[ps2fixer]

Wiring is somewhat simple, the CDI and the alternator are the main two things that change, everything else is based off those mainly.

Since this is a go-go type of machine, are you planning to run lights? No lights makes the wiring quite a lot simpler. When I make "race" harnesses with no lighting, they tend to run about 1/2 the cost of the full OEM style harness.

Alternator designs are mainly single phase (1 wire + internal ground like the 200x engine, or 2 dedicated wires like the 200s,200m, 185s, etc use), and the larger older machines, or the newer machines generally run 3 phase which has 3 wires from the stator. The physical way the power is generated is slightly different, but the only thing that really cares about that is the voltage regulator/rectifier if the machine even runs one. Like the 200x, there is no regulator, the lights use 100% of the power from the alternator which is about 70w. You can convert to LED to get more light, or buy a high output stator that has more windings than factory. Either case, if your lights draw less than max output, you'll have to atleast have a voltage regulator (2 wire like the 350x, 250r, etc), or a single phase voltage regulator/rectifier (generally 4 wire, 2 for AC in, and 2 for DC out, the AC and DC can't share the same ground so the 200x would require the battery and everything DC to never be frame grounded (floated ground)).

I'm not familiar with the turbo setups with carbs, but isn't the tank still physically above the carb, and with equal pressure on both sides of the fluid, shouldn't it natrually go down to the carb via gravity? You mention up to the carb, but I doubt you're mounting the tank below the engine. For the alternator, as the name suggests, it creates alternating current, aka AC. Very few machines generate actual DC power, it's effectively an electric motor that is being spun to create a charge normally called a generator on old car engines. Anyway, 100% you'll need a rectifier in the system if you plan to use 12v stuff which also means you should have a battery too. The simplest way is probably the single phase regulator/rectifier route and float the DC side of things, which means the fuel pump can't ground through the housing, it needs 2 dedicated wires. I have a couple regulator/rectifiers I've found, but haven't had a chance to test (I don't like bare hands in the cold and I'm in Michigan lol). One is an OE branded voltage regulator (no rectifier for AC to rectified DC), and the other is aftermarket designed for motorcycles. Both rate 200w+ so on paper they should work fine.

Again, I don't know the ignition timing requirements for turbos, but the stock CDI has a conservative but solid timing curve designed exactly for that engine. You can adjust the pulse generator (pickup coil in the automotive world) to advance the ignition timing as a whole to push the limits a little more or pull back the timing. Personally I'd stick with stock unless you really need to push the limits and know what you're doing. The basic concept of a CDI is basically it gets it's power from somewhere which on the 200x is the exciter coil (another coil on the stator that's high voltage), it has wiring for the pickup coil to know when to spark, also of course the output to the ignition coil to create the spark, and a kill wire to stop ignition. The timing in them is based 100% off the rpm of the engine. I haven't used a programmable CDI yet, but I suspect you'll get x number of points you can program, so like less than 500 rpm you have super retarded timing for easier starts, 500-1200 for your idle timing, etc till the max advancement at max rpm. Some likely have a rev limiter that can be enabled, I don't think the stock one does.

For a battery, you don't need much, it's basically just a voltage stabilizer. In theory a large capacitor would be possible too, but that gets a bit more advanced. For which battery to get, I'd stick with Honda stock brand Yuasa. For the size, it depends on the space you have, but here's the stock size for an atc200es - YB14A

https://www.yuasabatteries.com/battery/yb14a-a2/

If you're building the harness yourself, I'd 100% suggest getting the "B" crimp style crimpers and OE style terminals that are quality, not the cheapest ones around that are made in china on Ebay. When I first started out, my main source for tools, terminals, etc was here.

http://cycleterminal.com/

The individual connectors and such add up pretty fast. Good news is, you won't need any battery cables since you don't have electric start (or are you planning to get the Goki starter for it?). The 6mm ring terminal fits the battery well.



On the whole knock thing, are you talking about predestination (pinging), or a knock like a rod knock? Besides the extra heat and more power, I don't see how the turbo is any different from a well built engine. You'll need high enough octane fuel to handle the compression + extra air from the turbo plus the heat etc. You might need to upgrade the rod if anything is made, I don't really know the weak points of the 200x engine. Generally speaking, turbos respond well to lower compression (more air/fuel can be crammed in the same area), atleast that's what the diesel guys do. You can put an ATC200S piston in the 200x to lower compression from 9.6:1 down to 7.8:1. If I remember right, low compression also offsets some of the extra heat from running the turbo. Again, not really my specialty, just observations.

200s specs - https://atvmanual.com/honda/atc200s/1986-specs

200x specs (you didn't say year, but assuming 83-85, the most common years. If it's 86-87, then it's a completely different designed engine) - https://atvmanual.com/honda/atc200x/1985-specs

If you don't know the year of the engine, you can type the engine serial number in my vin/serial number decoder. Pretty sure it's lower left side of the engine below the sprocket.

https://atvmanual.com/honda/interact...er-atv-and-atc



Hopefully I didn't go too crazy with the electrical talk, if something doesn't make sense, let me know and I'll try to clear it up.


My site is somewhat new (about a year old), but I do plan to add the alternator types to the spec pages and maybe a quick reference table. My data source that has been quite accurate is the wire diagram in the Honda service manuals. They show good details like if it's internally grounded and such. I'm always open to ideas, I'm currently in a redesign of the back end of the site to make it more flexible. I built everything from scratch, no privacy stealing code and such except what google does with google analytics/adsense and such. Also very little java script, so the pages load fast and process fast.

One thing you'll need is a wire source. There's a few guys on ebay that sells wire that's not bad quality. I personally use wire rated for fuel injector harnesses (high temp) which makes it a bit stiffer than the other stuff, but the insulation doesn't melt so very friendly for soldering and such. I should have all colors you'd need on hand if you wanted me to put together some type of kit, just not sure how long you'd need for each color. Green (ground) will likely be the longest you'd need since it goes to nearly every part. Another route you could do is use the stock harness if it's long enough and add the extra wiring to the harness. That would solve the CDI/engine wiring, you'd just have to tap into the lighting coil wire and run that to the regulator/rectifier and add that stuff all external to the main harness.


Anyway, good luck with the project, welcome to the site, and we always love photos =).

[knappyfeet]

I admire you using the cdi......for this setup a computer is great.

ecotrons.com

Now that EFI systems are a norm...... for a turbo setup I would still go digital.

Good luck

[ARJ0019]

Big thanks to ps2fixer. I really appreciate the help and it has cleared up some things. I'm not planning to run a light, so hopefully that does make this easier. The only accessory I'm running is a fuel pump. The tank is between my legs, so I do have to pressurize the tank with the turbo and use the pump to lift the fuel. I'll keep this thread updated, or possibly make another for the project in general, and I'll get some pics up soon.

As knappyfeet mentioned, a computer is ideal for the turbo situation and it is actually what I'm use to. I have done significant engine tuning with Motec systems. However, if I can use a CDI I would really like to. There are advantages to and ECU that I need to consider. For example I wont have to pressurize the fuel tank with the turbo. I also would have more control over the fuel and timing which will allow me to ensure the engine runs well. The big downside to an ECU is cost, but with a microsquirt and some spare parts I have laying around it might not be any more expensive than a programmable CDI system.

Regardless of the way I go on this, thanks for all the help. More knowledge makes the decision process better defined.

[ps2fixer]

No problem. Pretty much of my understanding, the CDI route will work, just have to be a little more on the safe side with the timing, and and ECU you can push things further to eek out a little more performance. Back around the 70's Oldsmobile made an experimental 455 v8 that they twin turbo'ed and tested EFI as well as Carb'ed. If I recall correctly, both ended up roughly 700hp. I guess the performance for EFI wasn't good enough so GM didn't use EFI for quite a long time. I think around the mid 80's is when they started making it main stream. My dad was a big Oldsmobile fan, he used the 350/455 engines in trucks because they were known as the king of torque back then.

Anyway, this should be a pretty interesting project to follow. Small engine turbos aren't super mainstream except in the side by side world of what I'm aware of atleast. Would be pretty interesting to turbo an ATC350X, but at the same time it would probably be better for drag racing and such with that type of setup, not so sure if a trail rider machine would benefit much vs a high compression build.

I guess another thing you could really use is a wire diagram to visualize how things interconnect. This diagram is from the 83-85 Honda service manual. For the left handle bar controls, the only two wires you'd have to worry about is the kill and ground (E/IG, or G and Bl wires). Ignore the light wires (blue, white, brown, and the green sections not used which is ground). Yellow wire is the AC power source directly from the engine, that plus a wire to ground would be needed for a voltage regulator/rectifier's AC input.




Here's a wire diagram for the 82-83 ATC200E (simplest machine I can think of with a battery factory). Pretty much everything is the same + the battery and electric start wiring. Main focus points for your project is how the alternator is wired to the regulator. The stator doesn't ground on that machine so it actually has 2 dedicated wires. Red wire would be the charging/rectified DC+ out and the green is the neg (don't ground on your machine). A fuse is suggested near the battery so if any wire shorts out, the fuse blows instead of having an electrical fire. Besides that, it's as simple as wiring up the fuel pump to the battery with a switch inline to turn it on/off. Most atv ignition switches from that era are 4 wire, off shorts the ignition wires out, and on shorts the power supply wires, so that kind of switch would work for your machine to control ignition + fuel pump at one time. If you do end up using the stock CDI for the 200x, let me know which year and I can get a pin out, there were 3 CDI's possible, 83 rectangle 6 pin, 84-85 round 6 pin, and 86-87 4+2 pin.



Here's a quick reference guide for wire colors on the 200x

Green - Frame ground
Yellow - Power source (AC)
Black/red - CDI power source (exciter coil, high voltage AC)
Blue/yellow - pulse generator signal wire
Black/yellow - ignition coil signal wire
Black - kill wire (short to ground to kill ignition)


Lighting wires

Brown - Tail light
Blue - brights
White - dims

[Dirtcrasher]

No problem. Pretty much of my understanding, the CDI route will work, just have to be a little more on the safe side with the timing, and and ECU you can push things further to eek out a little more performance. Back around the 70's Oldsmobile made an experimental 455 v8 that they twin turbo'ed and tested EFI as well as Carb'ed. If I recall correctly, both ended up roughly 700hp. I guess the performance for EFI wasn't good enough so GM didn't use EFI for quite a long time. I think around the mid 80's is when they started making it main stream. My dad was a big Oldsmobile fan, he used the 350/455 engines in trucks because they were known as the king of torque back then.

Anyway, this should be a pretty interesting project to follow. Small engine turbos aren't super mainstream except in the side by side world of what I'm aware of atleast. Would be pretty interesting to turbo an ATC350X, but at the same time it would probably be better for drag racing and such with that type of setup, not so sure if a trail rider machine would benefit much vs a high compression build.

I guess another thing you could really use is a wire diagram to visualize how things interconnect. This diagram is from the 83-85 Honda service manual. For the left handle bar controls, the only two wires you'd have to worry about is the kill and ground (E/IG, or G and Bl wires). Ignore the light wires (blue, white, brown, and the green sections not used which is ground). Yellow wire is the AC power source directly from the engine, that plus a wire to ground would be needed for a voltage regulator/rectifier's AC input.

Here's a wire diagram for the 82-83 ATC200E (simplest machine I can think of with a battery factory). Pretty much everything is the same + the battery and electric start wiring. Main focus points for your project is how the alternator is wired to the regulator. The stator doesn't ground on that machine so it actually has 2 dedicated wires. Red wire would be the charging/rectified DC+ out and the green is the neg (don't ground on your machine). A fuse is suggested near the battery so if any wire shorts out, the fuse blows instead of having an electrical fire. Besides that, it's as simple as wiring up the fuel pump to the battery with a switch inline to turn it on/off. Most atv ignition switches from that era are 4 wire, off shorts the ignition wires out, and on shorts the power supply wires, so that kind of switch would work for your machine to control ignition + fuel pump at one time. If you do end up using the stock CDI for the 200x, let me know which year and I can get a pin out, there were 3 CDI's possible, 83 rectangle 6 pin, 84-85 round 6 pin, and 86-87 4+2 pin.

Here's a quick reference guide for wire colors on the 200x

Green - Frame ground
Yellow - Power source (AC)
Black/red - CDI power source (exciter coil, high voltage AC)
Blue/yellow - pulse generator signal wire
Black/yellow - ignition coil signal wire
Black - kill wire (short to ground to kill ignition)


Lighting wires

Brown - Tail light
Blue - brights
White - dims

Glad to see you around, you're always a wealth of excellent information!!

[ps2fixer]

Thanks, I haven't gone out of my way too much to get in on new topics, but if I get an email from an old thread, I normally reply if I can add something to the discussion =).

This kind of gives me an idea, like an app to "stream" you content from forums in the modern infinite scroll style. There's probably legal issues with that scraping the info and resending it since it would strip ads and such too. Would be neat to have one site/app to go to for all your forum topic needs though, I mean that's why facebook is so big, everything is in one location, general people are lazy, and it's the way to meet most people's needs. I have way too many projects to pick something like this up, but is an interesting idea/concept xD.

Funny little thing, it's been exactly 1 year since my last reply on this thread, to the day and an hour later, if you changed the 2021 to 2022 it could pass as a modern reply lol.