starting problem

gregjo1948

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Kohler CV750--When starting cold engine, I have to pour a splash of gas into the carb to get it to fire up. After it's starts, it runs great at idle all the way to full throttle and if I shut it down, it will start right back up. I installed a new fuel pump and cleaned the carb which didn't help. Any ideas????? Thanks, gregjo1948
 

EngineMan

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Yes I have one.......does the choke work..?
 

EngineMan

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If it runs well after you have put some petrol in the cab, I would still looking at faulty or misadjusted choke, did you remove the cab when you cleaned it, if so check for air leaks around the gasket. you can also check the fuel solenoid is working, you should feel or hear a click when you turn the key.
 

gregjo1948

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If it runs well after you have put some petrol in the cab, I would still looking at faulty or misadjusted choke, did you remove the cab when you cleaned it, if so check for air leaks around the gasket. you can also check the fuel solenoid is working, you should feel or hear a click when you turn the key.

The choke closes and opens completely. I removed the carb to clean it. I removed the fuel solenoid to be sure it was working as it should.
 

bertsmobile1

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provided the valve lash is adjusted properly, if it starts and runs good with fuel down the throat then it has to be the idle circuit in the carb.
With most carbs you can not clean the idle fuel passageways because after they are drilled the access holes are blocked off.
Some have removable blanking plugs some do not
There is carb cleaning , and carb CLEANING and Carb CLEANING
 

gregjo1948

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provided the valve lash is adjusted properly, if it starts and runs good with fuel down the throat then it has to be the idle circuit in the carb.
With most carbs you can not clean the idle fuel passageways because after they are drilled the access holes are blocked off.
Some have removable blanking plugs some do not
There is carb cleaning , and carb CLEANING and Carb CLEANING

I remove any and all jets that I can and soak the carb in carb cleaner then using compress air, I blow it out. I've been cleaning carbs successfully for nearly 60 years.
 

bertsmobile1

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And do you blow out backwards with low pressure air.
You idle circuit is blocked or the float level is too low or the choke is not working.
It has to be one of the 3 or a combination of them and I could throw in a duff plug.

As you say it nuns fine at low idle once hot that really points the finger strongly at either the float level or the choke, assuming that you do not have the idle stop adjusted up too far and are idling on the main jet

Don't mean to sound demeaning but some consider spraying some carb goo down the throat cleaning while others will have removed all blanking plugs, soaked it in a solvent cleaner for a day then finished off with an ultrasonic bath.
The latter is my method for stubborn carbs
 

gregjo1948

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And do you blow out backwards with low pressure air.
You idle circuit is blocked or the float level is too low or the choke is not working.
It has to be one of the 3 or a combination of them and I could throw in a duff plug.

As you say it nuns fine at low idle once hot that really points the finger strongly at either the float level or the choke, assuming that you do not have the idle stop adjusted up too far and are idling on the main jet

Don't mean to sound demeaning but some consider spraying some carb goo down the throat cleaning while others will have removed all blanking plugs, soaked it in a solvent cleaner for a day then finished off with an ultrasonic bath.
The latter is my method for stubborn carbs

Maybe you're not familiar with this carb or you're not reading my post. I "soak" the carb and I said the choke is working as it should. These engines aren't meant to idle at low rpm like a car or farm tractor. I didn't say it idled good once hot. It will idle as it should as soon as it starts and will also run full throttle immediately. As far as float, there is no adjustment. This carb isn't nasty dirty and full of old varnished fuel residue. Maybe instead of trying to imply that I'm stupid and that you're the world's top carb wizard, you might make an educated suggestion how to fix my problem.
 

bertsmobile1

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Kohler CV750--When starting cold engine, I have to pour a splash of gas into the carb to get it to fire up. After it's starts, it runs great at idle all the way to full throttle and if I shut it down, it will start right back up. I installed a new fuel pump and cleaned the carb which didn't help. Any ideas????? Thanks, gregjo1948

This is your first post
You say once started it runs great at idle all the way up to full throttle.
Now from that I read, runs at low idle which is 2200 to 2700 rpm for this engine up to high idle which is 3700 rpm.
You said you removed cleaned the carb but not how you cleaned the carb.

You follow up with once hot it starts fine.

This tells me that the enriching mechanism is not working.
Or the fuel you are using is old and the highly volatile fractions ( also called aromatics ) needed to start a cold engine have evaporated. ( something I neglected to suggest ).
We only know what you have written.
AFAIK your carb has a pressed in brass seat & a vitton tipped needle in which case the seat can be pushed up or down a small amount in the body once it is warm to change the float level
Being it is a CV750 I made the assumption that it is the 2 barrel Keihin which are regular PIA to get parts for as they are virtually exclusive to Kohler & Honda.
I don't have may of them in the service run but there are 27 Cub cadets with CH's in them and all the twins run the same carb in downdraught orientation as distinct to the CV's which are side draught.

AS mentioned it is not uncommon to have to soak a carb in solvent cleaner for a day the follow up with and ultrasound and some times this process done multiple times before I get idle passageways clear.
Normally I would not bother with such intense cleaning but these are really expensive carbs as I am sure you are aware.

We have no idea of you level of competency unless you tell us so responses get pitched to a low level.
Sorry if you find this offensive but unless told otherwise we assume you are not proficient with small engines.

You mentioned you replaced the fuel pump but not that you had tested it and found it wanting which suggest either impatience , which is understandable if you have grass to mow or are not fully conversant with small engines.

It can be very frustrating from this end because we can not hear, see or smell the engine so we are working purely from the given text.
For example you could have a dud valve lifter that does not lift the inlet valve fully untill it gets full oil pressure, something which has a distinctive sound.
Ditto with an exhaust valve choking the engine at cranking speed
A blown head gasket
A stuck inlet valve
They all have distinctive sounds when cranking and/ or when accelerating.

If I get my jollies by demeening people I would be a Farce Book troll.
I am here to learn and to help
 
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