Set timing on a 2002 xr250r

The CDI timing is locked in by the key in the flywheel (or so I just read). The valve setting is as such:

how do you set timing on a lifan 200cc trail bike? the bike does not have a timing chain it have pushrod how do set the timing do any one know

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Set the piston at top dead center (TDC), position the cam so that both valves are closed then assemble.
That engine is based on a Honda engine. The Honda has an overhead cam that is driven by a cam chain. The cam drives rocker arms that open the valves. So your statement about push rods sounds fishy.

Finding TOP DEAD CENTER (TDC) Casually

mgaguru.com/mgtech/engine/cs111a.htm

Other times it needs to be a bit more accurate, like setting the crankshaft straight ... assembled engine, and you can use the timing mark on the crankshaft pulley to ... are 360 degrees apart, or offset by one complete rotation of the crankshaft. With TDC on the compression stroke the intake and exhaust valves are both closed.

Finding top dead center on No.1 cylinder when timing marks ...

answers.edmunds.com > Edmunds Answers

Feb 21, 2010 - The crankshaft on a 4 cycle motor in never 180 degrees off between ... Because of this; the timing mark on the crankshaft pulley will be in exactly the same ... So it isn't necessary to know that distinction when setting ignition timing. ... If the exhaust valve spring is about to become fully relaxed, while the ...

Here are the 3 engines listed for this year. IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 2.4L SFI 4cyl

The Ignition Timing

18-22 DegreesBefore top dead center - When throttle positionsensor disconnected and using suitably programmedscan tool.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (750-850 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (700-800 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI SC 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chockdrive wheels, curb idle speed (700-800 RPM)transmission in neutral.

Check the timing it should be set at top dead center or a hair before top dead center, the other issue could be it's not pulling fuel which would mean it needs a good carb cleaning

set your piston to top dead center (tdc) then set the timing sprocket, their is 0 written on the timing sprocket and arrow of the cylinder head just make it center the 0 and the arrow.

you need to set it up on your fire mark not tdc and a simply rule of thumb take a card and use that to set the gap. some times you'll get lucky and they have the gap and valve specs on a sticker somewhere on the bike

owww,,, was the bike running when the chain broke?? There is usually some valve to piston contact when this happens - BENT valves will NOT SEAT or SEAL!! Time to disassemble the top end!! Especially if you heard noises coming from the engine when it broke? You need to set the piston at TDC (Top Dead Center) and like the cam up with the marks on the head and cam chain gear,---- Make sure the timing marks on the flywheel are lining up..if not rotate the engine another 360 degrees until they do before starting this..You MUST CHECK THE COMPRESSION before attempting to start this engine.

line the second mark on the flywheel up in the hole on the left cover that is top dead center, that tensioner i believe you have to prewind to bring it back take the bolt out and use a small screw driver and wind it back in and leave it in there untill you put the cam back in and bolt it down. make sure you use caution when removing the bollt from the tensioner it is spring loaded. the cam sprocket has lines or dots they will need to line those up with the gasket surface make sure there is no press on the valves that will be top dead center comp