Savage3

Check inline fuel filter as well, make sure you have good flow to carb by removing fuel line and letting it flow into safe container.

FUEL SYSTEM TROUBLESHOOTING Engine cranks but won’t start • No fuel in tank • No fuel to carburetor • Too much fuel getting to cylinder • No spark at plug (ignition malfunction) • Air cleaner clogged Engine idles roughly, stalls, or runs poorly • Idle speed incorrect • Ignition malfunction • Rich mixture • Lean mixture • Air cleaner dirty • Insulator leaks Lean mixture • Carburetor fuel jet clogged • Fuel filler cap vent hole blocked • Fuel filter clogged • Fuel line kinked or restricted • Float valve faulty • Float level too low • Intake air leak Rich mixture • Starter valve stuck open or damaged • Float valve faulty • Float level too high • Carburetor air jet clogged • Air cleaner dirty

You need to determine which carb was installed, i believe the early models had a variant with a second bypass screw. The pilot screw is generally set at 2 1/4 turns from the factory. Good starting point Bud. Generally speaking, if the screw is on engine side of carb, it usually adjusts fuel. If on air cleaner side of carb, it adjusts air. Many times, ( you can tell by reading plugs) if it is lean or rich. Most common problems i see are lean, the idle circuit gets varnish from ethanol and sitting.

https://www.aservicemanualpdf.com/Samplepages/SM-1986-1989 Honda TRX350 TRX350D Repair Manual.pdf?utm_source=copilot.com

The preferred method would be a scope. Dvom with peak voltage adapter works fine as well. Resistor, diode, and led in series will also work. Main point is, we find out if the cdi has both input and output signal, hopefully, eliminating that component as the problem. We are hoping for a poor ground or open circuit.

You can also disconnect kill wire from cdi. If spark returns, then you have faulty kill switch or short in wire.

Don't forget to check that kill switch as well if you haven't already done so. Check to make sure the signal is getting from trigger coil to cdi as well. We know you had signal from trigger, but, is it making it to the cdi. If not, cdi will not send signal to ignition coil.

So, you're not getting signal from cdi to coil. Possibilities: can you trace that wire back to where it attaches to cdi? See if you have signal at the pin on cdi. Test the wire itself at both ends, ensure you have continuity on the wire itself. Your meter may simply not be fast enough to read signal without adapter.

Unhook the wire from coil. Put black lead on good ground. Red lead on wire that attaches to coil. Make sure it is in neutral, brake pulled. (in short, safety requirements met) What is the voltage reading? I believe yours is ac cdi and you should receive an ac pulse. Hopefully your meter can catch it without a peak voltage adapter. It may not be accurate, but, at least we will know you have signal and the cdi is working.

OK sir, got it. Sorry, I misunderstood. Now can you get a reading while cranking on the hot wire that attaches to the coil?

No sir.......im referring to your ignition coil. The one that has a spark plug wire. It attaches to your spark plug. This coil has two separate coils inside. Please see the video I've attached above. I need you to test this coil, both primary and secondary.

Can we revisit the main coil again? Please watch video posted above and provide resistance readings on both primary and secondary. Get specs from your manual and compare sir. Disconnect coil from circuit when testing Boss. The main coil that attaches to the spark plugs is comprised of 2 separate coils. A primary and secondary. Please make sure both meet specifications. Thanks.

I found the diagram. Check the engine stop switch. That goes straight to cdi and could be the culprit of no signal coming out on orange wire from cdi. The two wires coming out of switch should show continuity with switch in on position. No continuity in off position. Between R/W and R/B

If ya can, put stator back on, crank it, post reading coming out of trigger coil. Should be low AC reading. Please post results

Is the battery fully charged? No problem cranking? What is the exact model number? 2002 BT? 250? Etc.....

Slim sir, I suspect you could have an issue with your safety circuit blocking spark. Example: the hand brake switch may not be working properly, neutral switch, on/off switch etc. Look in your manual at starting circuit. Follow troubleshooting steps. Ensure all conditions are met and signal is making it to your components. Ie....the orange wire. Meanwhile, I'll look for a wiring diagram and identify possible specific testing points that may resolve the problem. Post any diagrams or manuals you have that would be helpful. Im not sure when they would be visible, but, worth a shot.

Example of coil testing results

https://www.manualslib.com/manual/826392/Yamaha-Yfm250xl-C.html?page=43#manual

You also have a trigger coil that you can check air gap, some are permanently mounted and cannot be adjusted. You could also check the trigger coil for resistance. Once again, dynamic testing is much more effective. You would need a peak voltage adapter for your meter to produce accurate results during dynamic testing. The multimeter is not fast enough to capture cdi and pulse coil readings. The resistance testing will let you know if the components have a ground fault or the ability to carry current. Worth checking out while you have it apart. Go to manuals lib. and download a service manual to obtain accurate specifications. Otherwise, no sense performing the test. You need to know what the readings should be. Also, RM Stator has accurate you tube videos on how to perform all these tests. Rocky mountain atv does as well. Lets us know the results of your testing. Hope this helps Boss

OK sir, let's start at the beginning. The coil, actually has 2 coils inside. Primary and secondary, let's start with that. Keep in mind, resistance testing or static testing oftentimes produces inaccurate results. Ill post a video highlighting how to perform tests.

The ATV fuel petcock with ON, RES, and PRI (Prime) positions is a vacuum-operated valve that controls fuel flow from the tank to the carburetor. Here's how each setting works: ON | Fuel flows only when engine vacuum is present | Normal operation | Prevents flooding when engine is off. RES (Reserve) | Draws fuel from the bottom of the tank | When fuel is low and ON stops supplying | Gives access to remaining fuel before refill. PRI (Prime) | Bypasses vacuum system; fuel flows freely | After carb maintenance, dry starts, or vacuum issues | Must be turned off after use to avoid flooding or oil contamination: - ON is your go-to setting for everyday riding. - RES is a backup when you're running low—switch to it only when needed. - PRI should be used sparingly: - To fill the carb bowl after it's been drained. - If the engine won’t start due to lack of fuel. - Never leave it in PRI when the engine is off—it can cause fuel to leak or flood the engine. One things is certain, you don't want to continue making adjustments to carb until you have solved fuel flow issue. Hope this helps sir.

Exactly sir! Or run a jumper wire......the neutral switch has a bad chassis ground. The switch is wired into cdi, no ground equals incomplete circuit. Incomplete circuit = no start. The cdi is shorting the ignition circuit because it thinks the bike is not in neutral. Therefore, the ground fault is the problem. Test circuit and switch. Test from negative battery terminal to neutral switch for good ground. Key on, run switch on....etc Test switch itself as well, keep testing until you find the bad ground. Read no spark thread I listed above, most likely testing procedures in that thread.

Check the neutral switch. The switch may have failed and is grounding the spark. In your case, I'd look at starter button as well on handle bar. If I remember correctly, I believe the neutral switch is wired to the button and a cut off relay as well. Check the wiring diagram first. I believe Mech is on the right track.