Topic: Kick feels jerky after oil change

[mathias2803]

Hello! After changing oil, filter and cleaning the pan the kick feels different, feels jerky and dry ish.. I have kicked it over many times and used the starter to make sure oil has had time to circulate. I think its quite some time since the oil was changed last time. When using the starter and trying to start some smoke is coming out of the pipe.

Have not been able to start after the change. If I open the chocke fully and hold the throttle fully open it will start, but dies immediately.
Gas has also been spotted on the sparkplug and in the oil and black plugs.
Going to change the float valves to new 2.5 ones I just ordered for 80$ since I suspect the aftermarket ones may be leaking.
The bike was not running perfectly before this.. The idle was not good, but it was running great when riding.

Checked the spark on the plugs and the spark seemed to be all over the place. Going to switch from the NGK iridium my old denso U, tho I understand this won't help much. Also have NGK caps with resistors built-in.

Sent fra min E5823 via Tapatalk

[bryanj]

What bike

[mathias2803]

What bike

Sorry cb750 73 sohc.
Stock airfilter,
exhaust 4-1 with baffle,
5ohm coils,
stock jets 40 110.
Lithium 4Ah battery.
Tried again after cleaning and replacing plugs. Had to fully chocke and give some throttle, it started but died again and won't fire up. Screws turned out 1x 360* rotation
Spark on plug is all over the place and spark between ignition points seem weak?

[Don R]

 It sounds flooded, have you checked the float levels?

[mathias2803]

It sounds flooded, have you checked the float levels?

So far I just checked the bowls while mounted on the bike.. The bowls were maybe half full or less.

Sent fra min E5823 via Tapatalk

[evinrude7]

have you done the 3000 mile maintenance? 

[mathias2803]

have you done the 3000 mile maintenance?

I have done alot of maintenance and VERY little riding.
Changed ignition points and con
Coils
Sparkplug wire and plugs
Timing chain
Cleaned and rebuilt carbs
Oil
Replaced gaskets and some seals
Intake boots
Airfilter

Going to do a compression test when I get the tool. Last one I bought were for two different sizes and both were to big to fit the sparkplug hole.


Sent fra min E5823 via Tapatalk

[beemerbum]

I had a similar situation after rebuilding a K1 750. After the first oil change, the problem gradually diminished

[evinrude7]

have you done the 3000 mile maintenance?

I have done alot of maintenance and VERY little riding.
Changed ignition points and con
Coils
Sparkplug wire and plugs
Timing chain
Cleaned and rebuilt carbs
Oil
Replaced gaskets and some seals
Intake boots
Airfilter

Going to do a compression test when I get the tool. Last one I bought were for two different sizes and both were to big to fit the sparkplug hole.


Sent fra min E5823 via Tapatalk

so you've set the valve lash and have the timing set correctly?  what brand points? 

[SohcCBs]

Why it's not starting is either spark or fuel...from your description it sounds more like a fuel problem.  That does not however address your original question.  I think you've got to look at oil pressure or circulation, before trying to start it.  Keep kicking it over and see if it changes or feels more normal....kicking.  If it starts very briefly, that might get the oil where it needs to be, but I wouldn't start and run it until you know the oil is circulating properly.

[mathias2803]

Why it's not starting is either spark or fuel...from your description it sounds more like a fuel problem.  That does not however address your original question.  I think you've got to look at oil pressure or circulation, before trying to start it.  Keep kicking it over and see if it changes or feels more normal....kicking.  If it starts very briefly, that might get the oil where it needs to be, but I wouldn't start and run it until you know the oil is circulating properly.

I got it running after some fiddling. It's been very back and forward with the problems... It started up nice and keept on running. The idle was uneven as it got hotter and I had to adjust the idle screw alot to keep it from dying. But after a while it died. I checked the plugs and they were all clean. Now it starts when the chocke is fully on and the throttle fully open but dies out again immediately.
The oil lamp is turning off after a few kicks.
I think fuel might be the issue too at this moment. The problem gets worse when the bike is hot

[SohcCBs]

See carb tuning and some other info.  Consider a compression check.  Valve adjustment....timing.....

https://salocal.com/sohc/tech/tech.htm

[mathias2803]

See carb tuning and some other info.  Consider a compression check.  Valve adjustment....timing.....

https://salocal.com/sohc/tech/tech.htm

Thanks will do!

Sent fra min E5823 via Tapatalk

[SohcCBs]

If you're having to open the throttle and close the chock to get anywhere, it's probably running lean, considering the plugs are still clean under those conditions.  Check the gas tank vent too.  Make sure it's clear....has air going thru.

[mathias2803]

Apparently I have 135# main jets in the carb which is wierd since the bike was stock when I got it and ran good as far as I know..



Sent fra min E5823 via Tapatalk

[SohcCBs]

An F or K model?  4 to 1 wouldn't be stock on a K of course....and some one might've changed the jets.  The previous owner stated it was running or were you riding it?

[mathias2803]

An F or K model?  4 to 1 wouldn't be stock on a K of course....and some one might've changed the jets.  The previous owner stated it was running or were you riding it?

K model. The bike was stock and ran good back then with 135..?  I mounted the 4-1 later.

Float bladders show different measurements, one is 26 while the other is 28. Bend it?

[MauiK3]

I know there is much debate around this but I'm a fan of the clear tube method of checking actual float level. I feel it reveals, for reference, the static level of fuel in the bowl with the bike on the center stand. It's a good place to start.