Roketa GK28 No fire after all parts change out

[lwmatch]

Greetings:
Great site with a lot of info, but hadn't found 'the answer'.
Bought a non- running GK-28 last week that was parked, running, and when to use again a couple of weeks later wouldn't start. Owner let it set because son had grown tired of it, so took it off his hands for my Grandkids. Anyway reading the 'no spark' chinese manual, bought a cdi, coil and magneto.
Went thru the steps of disconnecting the kill wire, and then changing out cdi, then coil, then magneto. Still no spark. I get to reading on this forum about ac or dc cdi's and wonder, if possible that the power rev cdi box pt#42, I bought, could possibly be an ac and not a dc box. Oh, and yes using new sparkplug with a good engine ground. Please help, got Kids waiting!! Thanks, Larry

[SYCARMS]

Usually when you use an AC cdi on a dc system you will hear a fairly loud pop as you blow the cdi. I would start at the switch and make sure the switch is supplying power to ignition. Look really good for loose wires and trace using a volt ohm meater. If your manual is a service manual it will give you all the numbers needed to check the components. Also make sure all grounds are made and check the fuse. Some wire the fuse in the ign switch supply and others wire it to the ignition to where it will turn over but have no spark.

TOM

[lwmatch]

Thanks Tom
As I see it, my system fires as a magneto, not requiring a voltage source supplied. The key switch only function looks to be to spin it over and close the circuit on the b/w wire to ground it in the off position. Same simple system as my pull start lawnmower.
I just don't know if that fancy max rev. CDI I bought SUPPOSED to have a 12 volt feed or not. It has the same 4 pin 2 pin connector, but no instructions. In the old days when the lawnmower wouldn't fire, the flywheel key would be slightly sheared. [Showing my age on this one]. Should have bought the simple replacement but trying to do one better and may have bit me. This buggy, the lights etc. don't work unless the buggy is running. Wish I had another factory stye CDI to try without the 7 day wait to get one thru the mail. Thanks again, Tom, I'll look somemore.

[SYCARMS]

Your correct about the stator suppling power to the ignition, however the reason I mentioned to check the ign. switch is that if bad it either grounds out the ignition to where you will get no spark or you loose voltage to the coil. The stator only fires the trigger switch to tell the coil to send the spark to the plug. I have seen more than once the ignition switch causing a no spark condition. I would recomend to check the switch which is the start of the circuit. To determine if you need an AC or DC cdi look at the small plug in at the cdi. If it has one wire your wired for a DC cdi if 2 wires are used its wired for AC. The DC cdi will be larger then the AC cdi. Other than that the person selling the product should know if it is a DC or an AC cdi he is selling you. You have no way of knowing since a writting is in Chinese. If I can be of further assistance feel free to give me a call @ 662-301-1563

TOM

[lwmatch]

Originally Posted by SYCARMS

Your correct about the stator suppling power to the ignition, however the reason I mentioned to check the ign. switch is that if bad it either grounds out the ignition to where you will get no spark or you loose voltage to the coil. The stator only fires the trigger switch to tell the coil to send the spark to the plug. I have seen more than once the ignition switch causing a no spark condition. I would recomend to check the switch which is the start of the circuit. To determine if you need an AC or DC cdi look at the small plug in at the cdi. If it has one wire your wired for a DC cdi if 2 wires are used its wired for AC. The DC cdi will be larger then the AC cdi. Other than that the person selling the product should know if it is a DC or an AC cdi he is selling you. You have no way of knowing since a writting is in Chinese. If I can be of further assistance feel free to give me a call @ 662-301-1563

TOM

First, Thanks, Tom, for taking the time to talk to me on the phone!
Quick question : What are the wires on the carb. for? Not getting fuel, getting fuel thru vac. bowl switch to carb., but not going thru carb. yet. Will run when spraying fuel into the carb. inlet. Will pull off tomorrow.
Update on the electrical. Roketa GK-28 I have is a magneto powered ignition system, not using an external 12 volt power source. My firing issue was a cluster, replaced the CDI with a performance 6 pin cdi that didn't fire, coil didn't, new mag didn't, my mag trigger voltage was not a constant 1.2 volts, so pulled mag back out, ohm checked my mag and my b/r wire that powers the cdi from the mag was showing continuity to the 3 wires that go to the charging rectifier. Basically grounded out. Put in the old mag. and the old cdi box and got fire. The performance CDI box, which is also 6 pin like my old one, requires a ground wire to the 4th port in the 4 wire connector, unlike the factory one. Moral of story, throwing on new parts sucks if [1] takes an added wire you don't know about, and [2] just because a magneto / stator is new, doesn't mean it will work!

[SYCARMS]

The wires to the carb are for the enrichment valve. When the engine is cold the fuel needle in the valve is retracted, as the engine runs a reduced voltage is applied to the valve heating it and expanding the fuel needle until enrichment jet is blocked. So unlike a choke where it cuts air supply to enrich the mixture, the enrichment valve allows more fuel to flow through it's own circuit when engine is cold. I would go to napa and purchase a gallon of Barryman B-9 chem dip. Totally tear down the carb making sure all rubber and plastic is removed. Set the carb pieces including jets in the provided basket and let soak for several hours. Remove basket and let drain, hose off parts with water then blow off with compressed air paying attention to all orrifices and jets. It sounds as if you have a blocked jet and or passage due to setting up with the garbage fuel available with ethanol. Give me a call tomorrow if you have any questions.

TOM