QuestionQUESTION: hi, i have a craftsman model no. 917.271022 with a 15.5 horse kohler engine. engine cranks but will not start, it for sure has good spark and fuel delivery i was not able to conduct a compression test because i didn't have the tool at home. the engine is ohv so i pulled the valve cover and found that the exhaust valve didn't seem to be moving as far as the intake valve. With time on my hands i pulled the engine and the pto cover and inspected the camshaft lobes. They seem to be different sizes which might explain the difference in valve movement. The engine has hydraulic lifters. Could it be a bad lifter? when the engine was cranking it would backfire and sputter. new fuel filter, spark plug, fresh gas... not sure where to go from here. ran fine last year and wouldn't start this year. any information would help. thank you.
Seth
ANSWER: HI SETH
A BAD LIFTER THAT HAS NOT PUMPED UP MIGHT EXPLAIN THE EX VALVE NOT OPENING FULLY
USUALLY BOTH CAMSHAFT LOBES ARE SAME SIZE
A BENT PUSH ROD MIGHT DO SAME THING, BUT VALVE CLEARANCE WOULD BE EXTREMELY WIDE
CHECK THE TIMMING KEY MAYBE SHAWN
DOES THE CARBY HAVE A AFTERFIRE SOLENOID ?
MAKE SURE THAT SOLENOID IS OPENING UP WITH 12 VOLTS FROM THE IGNITION SWITCH WHEN TURNED FROM START AND RUN
CAN YOU LET ME KNOW MODEL AND SPEC NUMBER FROM KOHLER WHITE TAG ON ENGINE COVER
IN THE MEAN TIME HERE IS WEB SITE FOR MANUAL
http://www.kohlerplus.com/
login as quest
go to service literiture
select you engine type
down load a service manual
cheers paul
get back to me with model and spec numbers
---------- FOLLOW-UP ----------
QUESTION: Hi Paul, Thank you for your quick answer to my first question. first i will give you more info. on the engine (kohler engine-model number is CV15S, Type number is PS-41567. After further inspection of the engine i found that the exhaust cam lobe has a "compression release?" as far as i can tell. Is it possible this is for ease of starting? Not too sure what this is for, but it explains why the exhaust valve has different movement when cranking. I ordered lifters and gaskets to re-assemble the engine later this week, i also ordered a carb rebuild kit but everything looks ok in carb. This carb does have an afterfire solenoid, with solenoid still in carb i crossed wires over battery terminals and it does click. I also checked the flywheel key and found it to be ok. The spark plug was full of gas everytime i pulled it after trying to start the engine. I will do a proper compression test once i re-assemble the engine. Could the afterfire solenoid be causing engine to flood every time? Thank You Paul.
Seth
Answerhi seth
there are 2 types of valve rockers in these cv units
1 is a separate rocker and push rod for each valve with no bridge and bolt down with a
pivot bolt and have a hydraulic lifter no valve clearance is used and are non adjustable
2 the other is a hydraulic lifter and push rod for each valve and has a guide plate keeping push rods in line with rocker with no bridge between rockers these units have a valve clearance adjuster nut and loc grub screw in the middle and are adjustable
you should see a adjusting nut and a loc grub scew in the middle of it
be sure you have a spark every time on cranking because a faulty coil can make you think you have a fuel flooding problem Have the coils tested at the local shop on a tester
for your info they should be able to jump a 6 - 7 or mm gap no problem if coil is in shape
make sure you compressiion test and also check that you type of engine has not just got a tight valve clearance holding the valve open ( this can be heard back at the carby as a hiss)
a burnd inlet or exhaust valve could cause not to start
1 inlet fuel blow back towards carby when try to compress fuel /air mixture
2 exhuast allowing mixture to exscape along with compression and also a lean out of mixture
if it was running
make sure that fuel pump is not letting fuel flow from stuck open one way valves
make sure the fuel inlet needle valve is free and shutting off fuel flow and that the float hieght is set and float has no fuel inside it ( you can see it if you hold it up to a light )
check for debris in carby and tank unless you have already done it
cheers keep me posted as to what your findings are
paul
