View Full Version : 20 hp kohler trouble


buzzer12
06-29-2007, 06:52 AM
i put new rings in, new lifters, push rods. new cam, new muffler,also new carb. engine starts but but when i throttle up gas shoots up and out of the carb. there is good vaccum in crankcase. did a compression check 90 lbs on each side, it should be at least 120. does anyone think the intake valves need replacing. would this cause gas to come out of the carb. engine is out of my 1999 walker here are the spec's mod# ch 20s spec# 64554 dis# 624 ser# 2922306151 any help would be great thanks (also new head gaskets)

justin3
06-29-2007, 07:36 PM
Did you set the valve lash correct between the rocker arms and valve stem?

buzzer12
06-30-2007, 12:17 AM
could u explain how to do this?

justin3
06-30-2007, 01:45 PM
Set your engine at TDC (top dead center) on the compression stroke so both valves are closed. You need to look up the valve lash specs from Kohler. To set the lash you use a feeler gage and set the distance between the valve stem and rocker arm to its proper lash by loosening the rocker arm.

buzzer12
06-30-2007, 06:21 PM
where do i put the gauge ?

scrench
06-30-2007, 09:55 PM
these valves are not adjustable , also you should run 10-30 in it (hydraulic lifters) depending on the ammount of vapor you are seeing , some is going to be normal , could be a few things causing it , what plugs are in it should have rc12yc (champion plug) # , could be choke setting make sure the choke is opening all the way up , plug gap double check it , is it just vapor ? or does it look like old faithfull , does it just do it when you throw the throttle to wide open , or does it do it when the engine is running at full throttle , some mist is going to be there when it is running , did anyone work on the carburetor (might have put the wrong venturi in it ) rpm can also have an effect on it .90 sounds ok on the compression , has compression relief on the cam) also if it has not ran much might need to give the rings time to seat , did you have it bored , or hone it ,

30yearTech
07-01-2007, 12:25 AM
Buzzer12, I have a service manual for this engine in "PDF" format, pm me if you would like a copy and I will email it to you

justin3
07-01-2007, 01:33 PM
Sorry for misleading you buzzer, I forgot Kohler's Hydraulic lifters are no adjustable. I was thinking of Briggs and Tecumseh engines.

30yearTech
07-01-2007, 02:58 PM
Sorry for misleading you buzzer, I forgot Kohler's Hydraulic lifters are no adjustable. I was thinking of Briggs and Tecumseh engines.

You are not entirely wrong justin3, as some Kohler engines with hydraulic lifters are in fact adjustable. It just depends upon the specific model and spec as to whether it's set up with zero lash or not. :thumbsup:

scrench
07-01-2007, 09:46 PM
You are not entirely wrong justin3, as some Kohler engines with hydraulic lifters are in fact adjustable. It just depends upon the specific model and spec as to whether it's set up with zero lash or not. :thumbsup:


do you know what hp; they are , i have never seen one , with adjustable hydraulic tappets , thank you .

30yearTech
07-02-2007, 12:01 AM
do you know what hp; they are , i have never seen one , with adjustable hydraulic tappets , thank you .

I am not sure how many different models have the adjustable valves, but I have seen them on some of the newer command 15hp single cylinders.


http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=43274&stc=1
Kohler_CV_Adj..pdf

scrench
07-02-2007, 12:26 AM
ill be a monkeys uncle , ive never seen em but they do exist , parts smart don't show em at least not that i could find , might be a kit a guy could put on if he felt the need , i wonder if they are a flat tappet (solid ) kit humm might be , have you seen them b-4 ? i thought all kohler valve in head used non adjustable , i like the first design in the pdf , the one on the top left with the rod through the rocker , seems they would stand up better , have seen them , i did pull my hair out on a kohler 20 one time the thing came in with a dropped valve , i just thought the retainer came loose (governor) set at like 4500 rpm. anyway i done a valve job slapped the motor back on started it and ran for about 2 minn , done it again . so i tore it back down everything looked ok used putty on the pistons turned it over and sure enough interference , turned out the gear on the crank had turned , it was just pressed on , did not like that design , had to change the crank to fix , looked like they would have used the woodruff style , this could be a possibility on "buzzers' " , but i guess it could be the valves . possibly wet dry should tell something shouldn't it ? ,,,,,,,,, you are right man i have seen them on command 15hp yeppers , all that carb spray must be taking its toll on me , aint nothing right on the left side of my brane and on the right there aint nothing left , thanks 30

buzzer12
07-02-2007, 08:27 AM
all i know is that when it does start , at full throttle ,open choke . it spits fuel up and out of the carb . it will run fine at half throttle. now when i put the air filter back on an then try to start it it won;t start. this engine is in my walker and walkers must be at full throttle when cutting grass. it wont start with the choke on . it must be open wide , half throttle then it take a while but it will start . i just git to fix the fuel shooting out of the carb. if i undo the intake valves and crank it it does not shoot fuel out of the carb. is it time to take it to the shop . they want 150 to open the engine and 150 to close it, thats with out fixing any thing please helpppppppppp!!!

30yearTech
07-02-2007, 09:51 AM
It could be possible that the camshaft is out of time, are you sure you got the timing marks lined up when you reassembled the engine?

buzzer12
07-02-2007, 08:25 PM
yes i lined up the timming marks

30yearTech
07-02-2007, 10:01 PM
Perhaps the flywheel key is sheared, double check the key and make sure the ignition timing is not off. It really sounds more like a valve timing issue though.

buzzer12
07-04-2007, 09:40 PM
any more ideas pleasssssssssssssssssssseeeeeeeeeeeee

buzzer12
07-05-2007, 07:24 PM
is it time for a new engine???

30yearTech
07-05-2007, 07:58 PM
I really don't know what else it may be without physically looking at the engine. It sounds from your description like a valve timing problem but I just really can't tell much more with out actually looking at the engine.

Sorry! :(

buzzer12
07-06-2007, 08:59 AM
could u expline maybe what i should to fix this vavle timing problem . i'm going to take the engine out and break it down and start all over again. the engine has new rings, carb , cam. plugs,

30yearTech
07-06-2007, 11:45 PM
I said it sounds like a valve timing issue, but I don't know for sure if this is the problem. I would remove the sump and rotate the engine around and make sure the valve timing marks on the crankshaft and camshaft line up. I would rotate the crankshaft several times and look at the valve operation and the location of the magnets on the flywheel in relation to the ignition modules for each cylinder to make sure they are also in the proper orientation. If this all looks good then I would look at the valves and seats in each of the cylinder heads. Remember I am relying on a description of the problem and I think this indicates a valve timing problem, it could still be something else entirely, just nothing else comes to mind.