Honda CRF 450 R - Answered Questions & Fixed Issues

Is this a CRF450 single-cylinder off-road bike? If so: If it's coming out an overflow, it may be overfull. Not sure on that--haven't seen it before.To check engine/trans, drain, refill with (670cc w/o filter change; 690cc with filter change), start engine, shut off engine, check sight glass on side of engine. If it's low, add oil and repeat start/shutoff/sight glass routine until it's full. Engine and trans share oil.If it's still pumping oil out the overflow after you're sure it has the correct amount in it, be sure it's oil and not coolant, battery acid, or gasoline (there is a gas overflow tube on the carb for when the float sticks).

maybe get a new spark plug.make sure your grounded(earthed). did you take the plug out and check for spark against the motor while you cranked the bike over?

Damage to the spark plug is surely related and caused by a more specific problem , if you could repost a new question with a bit more details on your Honda is running what fuel or mixture your using and exactly which spark plug you are using, or better a photo or video of this burned up plug we could help more. Would you say you are experiencing any of these scenarios https://e3sparkplugs.com/blog/are-your-spark-plugs-trying-to-tell-you-something/ https://www.6ya.com/jacobsmith

if it has a battery fit a good battery as the system may require 12 volts to energize the ignition system properly

Check the water pump impeller .. the sound may have been the overflow... check your compression..just to be on the safe side..

Classic valve train issues. Sounds like the valves are tight. One thing that concerns me is the "sudden onset". Valves usually tighten over time.
Make sure you also tighten the cam chain as well.

did u try to disconect the cut off switch to see if it is doing the same . and if u keep the starting button in does the starter keep running along

Fifty something I'm nearly sure...

???

Engine after draining: 660cc Engine after draining and filter change:690cc Honda HP4 Synthetic 10/40

hope this helps good luck.......

A cracked head or blown gasket ether one has to be replaced. Good luck........

None. This is a very reliable bike and I don't sell them.

3rd from top unless your in high elevation then 2nd.

if it is a two stroke it will be in the crank area and not gearbox but as this is a 4 stroke the crank oil and gearbox oil are all in one ,you will need to change the oil and filter as well cheers pete

check your ignition switch.

May need new valves or valves clearance are not correct

Cylinder head mounting bolt 9.8n.m

There's two drain bolts near the gear lever ones engine oil and ones tranny oil

Engine oil 0.69liter at oil and filter change and transmission oil is 0.59 liter