I have a 6.5hp honda engine on a Gemini navigator kart that will not start and run. It seems to overfuel. I have checked Spark Plug and leads ok Oil change Fuel Change Cleaned Carb bowl Cleaned lines to Fuel carb bowl Engine Turns freely Any suggestions greatfully accepted

if it is electric start
you need a new starter solenoid
if it will not turn over on the kick start
then your engine is seized to solve the problem for this
remove you spark plug and put some thin oil down there and let it soak
for a day or two
remove the side casing and turn it over on the flywheel nut
until it is free
give it a few more turns and get the old oil out then
put your spark plug back in and start it

it could be a number of things. First check your engine oil level. Turn the engine switch to on and give her a pull over. No spark, disconnect the low oil level sensor - (yellow wire) and give her a pull over again.
If you get spark, and did fill your oil, you have a bad sensor. If still no spark, try another plug. Otherwise it is a bad coil or a bad high tension wire or connection from the coil to ground

i had the same problem with a go kart i had it could be your spark plug or fuel with the spark plug just pull it out put a metal screwdriver in there and try and kick it it should spark if it dont then theres your ploblem or check the fuel to see if its running thru to the engine.

At full throttle does it sound like the rpms are up enough? There is a good chance that the govener is not set properly.

Karcher Model G2650 OH with Honda 6.0 HP, GC 190 Engine. Engine won't start. New gas, has spark. Seems to flood instantly. Much gas in cylinder. Spark plug wet. Choke pulled out, power on. Oil OK. released pressure in line. Where can I down load a Honda Engine manual! Thank you !

Target your inspection towards the 'spark arrestor screen' in the outlet of the muffler.

Overfuel or 'rich' condition
Basics to check:
1) Spark plug - brown or dark brown - OK
a) is it carbon or fuel fouled
b) is there spark

2) Muffler remove for inspection
a) exhaust screen clean or plugged
b) inspect cylinder wall/piston as the flywheel is slowly rotated
3) Check Air filter for fuel saturation
4) Allow engine to run for 5 minutes to excess fuel from muffler
5) Fuel mixture ratio: Make sure the oil mix is per your manufactures recommendations
6) If after the above the engine is still smoking and blubbering:
Adjust carb mixture screws to a 'less rich' setting
*NOTE: only move mixture screws 1/8 of a turn at a time,
and try operation before any more adjustment

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

There should'nt be any fuel in your oil, it sounds like you might have a blown head gasket. If you think it might be overfuelling then remove the injector clips (don't mess up the order) and pour some fuel down the manifold and try start it. If it does'nt give a good effort at starting then I'd say you need to run a compression test. Sounds like you have a cracked block, warped head or bad head gasket.

When you turn the key to start, the engine cranks over? You must check for spark and fuel, if one is missing, the car won't run. Pull a spark plug, with plug wire connected and plug on a metal surface of the engine, have someone turn the key to start, while you watch for spark at the plug. It is easiest to see spark with car out of direct or bright light. If you have spark, attempt to start several times, pull a spark plug and check for evidence of fuel (wet) on plug. Let me know what you find, we can then continue.

sounds like you have a problem with the spark the coil may be on its way out or there may be oil in the spark plug holls shorting out the spark.
your best bet is to pull the leads out 1 at a time and and look down and check for oil if there is oil there get a new rocker cover gasket.
if no oil refit plug leads loosely and start the car remove one lead at a time slowly and look at the spark cumming out the end off the lead is it blue? if so it is ok if it is yellow and dull you have a coil problem. also check that the spark is only comming out the end of the lead as it may be comming ou the side of the lead and shorting to earth,
you can do this by slowly moving the lead around the top of the sparkl plug holl and see were the spark is comming from

be carfull no to shock your self as it herts like hell

good luck

call up karcher and tell them your problem