20 Most Recent 2004 KTM 640 Duke 2 Questions & Answers

Is the bike at stock condition?
Check the carb and the charging system.
You should measure 13,5-14V at your battery in 3000rpm with your high beams on.

any maintance tips?Piston seizures are due to lack of lubrication and/or a way too lean mixture - incorrect ignition timing unless it is a mechanical failure of the rings bearings or rod. Just like a car engine, there should be a thermostat in the cooling system, so that the engine can warm up quickly and maintain an even engine temperature. If the crank and rod is still okay, then check the mating surfaces of the crankcase to cylinder and cylinder to cylinder head. Be sure that the cooling system is clean and that the water pump is working okay. Bleed all the air out of the cooling system before you start the motor again. 2 strokes get all kinds of mods done to them, so it is hard to determine what the correct jetting should be unless the entire intake, exhaust and port timing are all OEM standard. Go with a richer jet and some non-synthetic oil in somewhat heavier ratios, to help break in the new parts. Adding more oil actually can cause the jetting to lean down, due to added weight of the fluid mixture slowing the flow through the jets. There are several Honda Elsinore MX websites out there to help guide you through the setup process, once the type and make of parts are known. Each manufacturer of exhaust and intake systems will have different setup suggestions. Always warm the engines up slowly, until the cooling system is circulating properly. Inspect the carburetor for any kinds of debris or contamination that could cause lean running and verify ignition timing specs. Intake manifolding and/or reed valves need to be checked carefully for air leaks/damage. If the bike was run HOT with failing cooling system, the damage to the crankshaft rod may not be visually apparent, so a crank rebuild may be in order, so you know that the bearings are not damaged. Considering that there was coolant in the crankcase, a crank rebuild really is a necessity, as old coolant will etch and damage ball and needle bearings, as well as the crankpin and rod end. If gasket failure isn't apparent, then you may have to have the cylinder and head pressure checked to identify any hairline cracks that may open up under heat and pressure. Use OEM Honda gaskets to prevent material failures, which can occur with after-market parts.,,,

your throttle cable is improperly routed and is being pulled on!

A worn wrist pin that attaches the piston to the piston's connecting rod

That would be like riding a fixed wheel bike.Think about how you will stop and start. Only hydraulic fluid will leak. Bad idea!

Question edited for clarity. That sounds like it is just a bad connection somewhere or possibly a bad switch. Remove the battery leads and clean the lead contacts and battery posts with a wire brush. Smear with Vaseline and reconnect. Remove the starter leads and do the same. Then it could be the Starter Relay https://www.google.com/search?q=ktm+450+sx-f+starter+relay+location Or Starter Button https://www.google.com/search?q=ktm+450+sx-f+starter+button+replacement ..

personnaly I would replace cylinder with new OEM

All dirt bikes have a VIN. It is on the steering neck. https://www.google.com/search?q=vin+on+my+ktm+300 ..

Have you checked battery connections. Run switch in the correct position? Checked spark plug for debris? Just thinking out loud..

Drain oil. Use degreaser to clean area. Use JB Weld & allow to set up properly before adding oil.

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Hi, try to see this link and looking for the manual that you need. https://www.pdfmotomanual.com/manuales/ktm/eng I hope to give you an help. Luca

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Hi, most likely your cdi unit or ignition coil needs replacing.

took me a min or two of WTF-ing to see pic and realize you meant a 2-stroke motorcycle..

try replace spark plugs

It's a bad seal of the head gasket. You need a new head gasket and to scrape every particle of debris from the cylinder head and cylinder surfaces that mate with the head gasket. Use the factory specified gasket sealing compound and do a clean job - no blobs or pools of the stuff. The head gasket should lay flat on the surface of the top of the cylinder, and you have to make this surface free of grit, leftover sealant and any other foreign matter before you put the head in place and torque it down. Start with the head bolts just finger tight and then go by the manufacturer's specs for the pattern and amount of torque to be applied. Usually it is recommended that you get to the specified torque amount in stages, going around several times and repeating the torque pattern until you get that maximum rated amount. This will prevent the seal from shifting or warping and should make the gasket seal perfectly. This is the old school method of doing this job. and I have never seen this fail to produce good results. Take your time, be clean, and you will have the results you want.

Check the clutch, adjust, clean, or replace

over full sump fuel getting into sump badly worn rings allowing excessive blow by

Worn out shift dogs.

Make sure cables are working . Follow it down to clutch and make sure clutch lever is actually moving. It is does then pull clutch in and pushbike backwards. Should release If not , plates are probably frozen through excessive heat. Replace them. If lever does not move when clutch handle pulled, then adjust or broken cable. hope that' it, easier and cheaper!