set up question for Helix 150cc

[COLDSTEEL]

Wish this was a chat to ask this will try to word it right.

Start of by saying, I have a Helix 150cc. I replaced CVT with 10gram rollers and just 1k spring. I replaced stocked carb with 28mm and came with manifold. I purchased a K & N style cold air intake and using the existing hose to raise it up. I purchased the stock muffler. So, my question is I did my research and found best to change my main jet. I purchased a set of 10 ranging from #107-#140. I plan to use #130 would that be ideal for my setup? If there is any other suggestions beside purchasing what I already have I would like to learn. My goal is not to race but want a reliable kart with reliable performance. I also purchased "other than stock" CDI and Ignition. Coil. It was a kit claiming "performance" but I am sure better than the stock one that was on there.

[neo71665]

Jet sizing depends on your elevation. First you need to do a plug reading to find out where you are now. If for some reason it's rich (highly doubtful but will come out black) you need to go down in jetting. If it's lean (white) you need to go up. Keep changing jets until the plug comes out a nice tan color. It's a trial and error that can take awhile until it's right.

[SYCARMS]

Where are you located? If you have a newer buggy using the DC volt CDI than the stock CDI will be the best since the mapping of the timing is set up for the heavier buggy the performance CDI's are all designed for the much lighter scooter. AC volt CDI were another story since all were designed around the scooter even the ones that come in the buggy.The hot coil will do nothing over the stock coil. If you were using the stock carb I would say a 122 jet but you are using a larger carb which may hurt your performance. Unless you have the test equipment for A/F mixture you will need to do a full throttle run. You will need 600-900 ft strait somewhat level road. From a dead stop go full throttle for 600-900 ft. With throttle at full throttle cut ignition off keeping full throttle until engine stops than pull over , pull plug and check color. It is important this is done just as I say, full throttle. If you coast for just a few seconds at closed throttle your test will show color of main and idle circuit. You do not want the idle circuit to come into play for you only want results of the main circuit which is at full throttle. You want the plug to be a tan to brown in color. Do not use a new plug for this test use an old already colored plug.

[COLDSTEEL]

OK. For both, I live in Pittsburgh, Pennsylvania. It is currently for sue "lean" (white and brown). Was reasoning being when I press throttle it does not have good response or it seems "delayed". Was not reason I replaced everything stated. Since I got a bigger carb I wanted to follow suite with air and spark. Sycarms I have DC. It is Helix 150cc (6150). I was only suggested to use #125 due to K&N type air filter. Then someone said #130. I am getting 10 of them from variety of sizes.

[neo71665]

I'm gonna bet you are gonna have to run something down in the 1-teens before you run in the 120s since you have the factory exhaust. Even with the opened up intake the exhaust is still pretty restrictive.

I'll second don't bother with the scooter CDI's. I was hard headed didn't listen when they told me, and still tried one. Ran it for about 2 hours before it found a home on the shelf. A coil is a coil. There is one on mine right now that actually was on a yamaha 350 big bear, it should be hotter if any of them are. I thought the buggy one was acting up and swapped it to test. Just haven't swapped back yet. The biggest gains on these (besides big bore) is opening the exhaust, opening the intake, and fine tuning the trans. I'm sure there might be some gains with playing with timing but I've yet to see an easy and cheap way to do it short of building and tuning a one off cdi system.

I will make a suggestion and quit swapping multiple parts at once. These small engines are so finicky small changes get pretty big results good or bad. It's a headache looking at parts waiting to be installed but it's way bigger headache tracing what exactly is wrong when you throw 2 - 3 things at it at once. Esp when it comes to a point you have to swap all those parts back out with stock to start troubleshooting.

[COLDSTEEL]

Gotcha on the multiple swap. I was told that once. Guess have to come here to be told right. It was told to me that these run at #117. I have a measure tool but havent got to that. "dont bother with CDI". I do understand that those are for "igniting" issues and it starts fine.I will follow thru on that. I got the "kit" so came with ignition coil and CDI. It currently runs now with the exception of the slow acceleration as stated. I plan to put all back together tonight and do a test run. Of course will return og any issues I know can be assist to be resolved here. Thanks brothers in advance!

[SYCARMS]

You have to get the jetting right. First as explained in previous post the main jet. Once the main jet is proper you can then look at the pilot or idle jet. If you need to adjust a/f mix screw more than 1 1/2 turns out than you will up that jet one size up. But first make sure you have no vacuum leak at intake, valves are properly adjusted and you have good compression. These 3 are a must to get a good tune on the engine. Download the service manual at americanlandmaster.com and go through all the checks, don't get into any hurry. Once you get it running great than you determine what it is lacking then that is when you buy the performance parts to enhance the power. You can contact me anytime with questions via this forum, e-mail or many times best to call 662-301-1563.

[COLDSTEEL]

Copy sycarms. Do u have a Facebook? I work from there so if u do just add me https://m.facebook.com/technologytranslated
yea, I did everything by the book and specs. I will put together and fire it up tomorrow and offer SITREP.

[COLDSTEEL]

So, it seems #125 is not right. With all stated parts. Started right up, then took it for a spin, first thing I noticed was terrible acceleration. I had better before. Then full throttle was worse and heard small backfiring and a few "hiccups" from possible the air intake. Before going with new main jet I completely closed air/fuel mixture screw and did a few turn in increments of 1/4. Adjusted the idle screw. All this after letting engine idle for 10min. Tomorrow plan to drop it to #120. Tomorrow will measure what size was in it and may find I shouldn't have messed with it. Did I miss any other adjustments?

[SYCARMS]

What was the plug color after your full throttle run?

[COLDSTEEL]

Light brown and white. Assuming I was lean. God damn. So I replaced with it #125. Swear to u no lie. I checked and rechecked everything. Niow no spark issues. Like this guy.http://www.buggymasters.com/forum/showthread.php?t=3052
Now tomorrow I do plan to check his solution but I know next will go back to original issues. (No wood to knock on). You know I build computers. Troubleshooting is same. But for god sake. Why no step by steps?
Can u give me the ignition components? The only question is that I have the ground wire that went to battery located behind seat. Since now I have battery on top. I used a 2nd wire connected via a but and bold for extension. I did NOT do this to positive (1 wire). I would check that but as stated the damn thing ran and started right up. The only thing I did was change the main jet! I am follow rule. Gas, Air and Spark. I have both but spark. I found if I stay on one it is easier. So just trying to figure out the ignition. BTW I removed both kill switches and completely cut them.

[COLDSTEEL]

OK. I will edit my last reply when at PC. I am on tablet. I may have found the solution. I will explain being I myself hate unsolved forums. So while doing my cdi and ignition coil replacement I cut and taped up the REAR kill switch wires. The front 2 wires (assuming they are kill switch wires) I assumed were the OTHER end of the 2 wires in rear I cut and taped. They are NOT. was reading that both 2 ends go different places. Initially I twisted the 2 in front together being that I thought the rear ones were the other end. Correct me if I am wrong. I just went out there snipped both wires completely. Low and behold, turn key and started right up! Tomorrow will hopefully be better and will allow me to finish this OP as SOLVED. Until then hopefully another person like me that reads EVERYTHING may find this as a solution. I am not good at forums. Stay tuned sycarms! Btw send me a pm to link to ur store. The time u all have gave me I would be willing to "invest" in yours!

[BuggyMaster]

After a lot experience with Helix machines my vote is you will be going up on that main. Not one time with bolt ins did I ever have to change the pilot jet. Don’t know where American sport works sources their carbs but they are unique. The factory main is way too small on it in stock form. With aftermarket air filter setup and an FMF exhaust we were at 140 if I remember right and I used a wideband sensor in the exhaust to tune it. I’ve got a thread somewhere detailing our trials and errors on our helix machines.

[BuggyMaster]

Here is an old but good thread. There’s a pic of what my spark plug looked like with a perfect tune (not the first spark plug pic)

http://www.buggymasters.com/forum/showthread.php?t=76