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valve lash check/adjustment
#1
B
Boit4852
B
Boit4852
Being the old persnickety coot that I am, checking and adjusting the valves on my Kawasaki FH580V v-twin has become a routine maintenance task that I actually look forward to performing usually in late October when it's cool outside. The specs are for .004" to .006" on all 4 valves. I've been setting the lash at EXACTLY .004" gap on all the valves for the reason of taking advantage of the maximum lift and duration of the cam lobe profiles thereby allowing maximum power output, plus, I find that this makes the engine mechanically very quiet with quick reliable starting. If it's hot outside, the engine will even start without the choke. It's a 2007 engine on an Exmark with 548 hours of hard usage. I do some repair mower work on the side and I have noticed that so far, every machine I've worked on had never had the valve lash checked. One relative brought me his 3 year old Craftsman lawn tractor with a B&S 24HP V-twin for me to replace both belts. After replacing the belts, I wanted to do a quick test to make sure everything was correct and the engine was hard to start and idled poorly once up to temperature. Without telling him, I checked the lash and found all the valves were out of spec, some worse that others. The lash specs are exactly the same as my Kawasaki so I set all valves at exactly .004" and the engine's issues were completely resolved. When he came to pick of the machine, I deliberately did not mention the valve adjustment. About 3 days later he called me and asked why changing the belts has such a profound affect on making his engine run like new, BETTER THAN NEW. When I told him that I had adjusted the valves, he admitted that he didn't know valves needed adjusting. That seems to be the norm.
#2
B
bertsmobile1
B
bertsmobile1
Singing to the choir with that one.
If I had $ 100 for every "unfixiable" engine that has come in in the last 5 years where the owner had replaced most or even all of the following ;-
1) battery $ 150
2) Starter $ 200 to $ 500
3) Solenoid $ 40
4) Seat switch ( cause they believe the air heads on U tube ) $ 10
5) key switch $ 50
6) oil $ 10
7) Spark plugs $ 7 ( each )
8) magneto coils $ 100 to $ 300
9) Carburettor $ 200
10) Flywheel $ 200-$ 400 ( U-Tube / Face ache experts again )
Then in desperation bring it to me cause all us ,mower repair shops are rip off and overcharge for everything, you would not be reading this & I would be laying in the sun in my Qld holiday house bought from the proceeds.
And yes at least once a year some one comes in having forked out over $ 1000 in unnecessary parts then bitches endlessly at my $ 60 bill.
If I had $ 100 for every "unfixiable" engine that has come in in the last 5 years where the owner had replaced most or even all of the following ;-
1) battery $ 150
2) Starter $ 200 to $ 500
3) Solenoid $ 40
4) Seat switch ( cause they believe the air heads on U tube ) $ 10
5) key switch $ 50
6) oil $ 10
7) Spark plugs $ 7 ( each )
8) magneto coils $ 100 to $ 300
9) Carburettor $ 200
10) Flywheel $ 200-$ 400 ( U-Tube / Face ache experts again )
Then in desperation bring it to me cause all us ,mower repair shops are rip off and overcharge for everything, you would not be reading this & I would be laying in the sun in my Qld holiday house bought from the proceeds.
And yes at least once a year some one comes in having forked out over $ 1000 in unnecessary parts then bitches endlessly at my $ 60 bill.
#3
B
Boit4852
My background with mowers stems from racing motocross when 4-strokes were beginning to take over the 2-strokes. By necessity and aslo my own personal interest< I did my own maintenance along with power improvements/modifications, but not confined to the engine, but to the suspension. After many broken bones, my M/X racing came to an end but my interest in things mechanical has not diminished. If anything, I am more fascinated and my thirst for knowledge has increased. BTW, when I hear people describe an engine as a 4-cycle or 2-cycle, I cringe. Internal combustion engines are ALL 1-cycle. 4-stroke engines take 4 strokes of the piston to complete ONE CYCLE. etc. Sorry. Had to rant. I'm okay now.
B
Boit4852
Singing to the choir with that one.
If I had $ 100 for every "unfixiable" engine that has come in in the last 5 years where the owner had replaced most or even all of the following ;-
1) battery $ 150
2) Starter $ 200 to $ 500
3) Solenoid $ 40
4) Seat switch ( cause they believe the air heads on U tube ) $ 10
5) key switch $ 50
6) oil $ 10
7) Spark plugs $ 7 ( each )
8) magneto coils $ 100 to $ 300
9) Carburettor $ 200
10) Flywheel $ 200-$ 400 ( U-Tube / Face ache experts again )
Then in desperation bring it to me cause all us ,mower repair shops are rip off and overcharge for everything, you would not be reading this & I would be laying in the sun in my Qld holiday house bought from the proceeds.
And yes at least once a year some one comes in having forked out over $ 1000 in unnecessary parts then bitches endlessly at my $ 60 bill.
My background with mowers stems from racing motocross when 4-strokes were beginning to take over the 2-strokes. By necessity and aslo my own personal interest< I did my own maintenance along with power improvements/modifications, but not confined to the engine, but to the suspension. After many broken bones, my M/X racing came to an end but my interest in things mechanical has not diminished. If anything, I am more fascinated and my thirst for knowledge has increased. BTW, when I hear people describe an engine as a 4-cycle or 2-cycle, I cringe. Internal combustion engines are ALL 1-cycle. 4-stroke engines take 4 strokes of the piston to complete ONE CYCLE. etc. Sorry. Had to rant. I'm okay now.
#4
B
bertsmobile1
And I cam in when the 2 strokes were taking over from the 4 strokes.
Had the chance to see Jeff Smith a while back ( world Champ several years running in the late 60's )
So there is a bloke 20 years older that I on a 1969 motorcycle showing 12' of air on the jumps
B
bertsmobile1
My background with mowers stems from racing motocross when 4-strokes were beginning to take over the 2-strokes. By necessity and aslo my own personal interest< I did my own maintenance along with power improvements/modifications, but not confined to the engine, but to the suspension. After many broken bones, my M/X racing came to an end but my interest in things mechanical has not diminished. If anything, I am more fascinated and my thirst for knowledge has increased. BTW, when I hear people describe an engine as a 4-cycle or 2-cycle, I cringe. Internal combustion engines are ALL 1-cycle. 4-stroke engines take 4 strokes of the piston to complete ONE CYCLE. etc. Sorry. Had to rant. I'm okay now.
And I cam in when the 2 strokes were taking over from the 4 strokes.
Had the chance to see Jeff Smith a while back ( world Champ several years running in the late 60's )
So there is a bloke 20 years older that I on a 1969 motorcycle showing 12' of air on the jumps
#5
B
Boit4852
John Banks on a BSA 441 Victor? Whether a 2-stroke or 4, all high performance machines are fascinating to me. Chassis, engines, or suspension. Love it!
B
Boit4852
And I cam in when the 2 strokes were taking over from the 4 strokes.
Had the chance to see Jeff Smith a while back ( world Champ several years running in the late 60's )
So there is a bloke 20 years older that I on a 1969 motorcycle showing 12' of air on the jumps
John Banks on a BSA 441 Victor? Whether a 2-stroke or 4, all high performance machines are fascinating to me. Chassis, engines, or suspension. Love it!
#6
B
Boit4852
B
Boit4852
There are many valve train designs. There are DOHC(Dual Over Head Cams) with shims-under-buckets valve lash adjusters and then all the way to the simple screw-type lash adjusters. Formula 1 has been experimenting with nitrogen filled bladders that replaced conventional valve springs. These F1 designs were designed to allow engines to operate in extremely high RPM reliably. We're talking in the range of 17K and even higher. Some sport motorcycles of today from Japan have engine RPM redlines approaching that limit. These engines have only a short service limit of a few hours, about 2 hours before they fail. What I'm getting at is to get the most reliable service from your engine. Adjust those valves often and perform all the other typical maintenance items. Overkill on your maintenance and you will be rewarded by lower repair and downtime costs. Makes sense?
#7
M
motoman
M
motoman
lve lash check/adjustment
As we try to absorb the electric motor specs of "horsepower @ zero rpm." Strange to us gas users, but I love to watch the fork-lift- motor- powered hatchback lay down the 12 second 1/4 mile time while dusting the muscle cars. The guy built it in his garage.
As we try to absorb the electric motor specs of "horsepower @ zero rpm." Strange to us gas users, but I love to watch the fork-lift- motor- powered hatchback lay down the 12 second 1/4 mile time while dusting the muscle cars. The guy built it in his garage.
#8
cpurvis
cpurvis
Having trouble absorbing that "zero rpm horsepower" concept myself. Zero rpm "torque", yes.
#9
B
bertsmobile1
B
bertsmobile1
But no one understands torque and probably won't for the next 100 years.
Which is funny when you think about it cause it is getting close to 100 years since we started to replace horses with engines so there would be few that actually had ever used a horse to power anything.
I do know some old ( very old ) farmers who still call their impliments things like a 20 horse plow and it is quaint to hear them say things like put the 10 horse harrow on the 554 and run the east paddock.
AS for fork lift motors. I got a towmotor cam for one of our LPG vans and it went from 15k / litre to 25k / litre and we never used 2nd gear again, sort of makes you think twice about conspiracy between engine makers & fuel companies
Which is funny when you think about it cause it is getting close to 100 years since we started to replace horses with engines so there would be few that actually had ever used a horse to power anything.
I do know some old ( very old ) farmers who still call their impliments things like a 20 horse plow and it is quaint to hear them say things like put the 10 horse harrow on the 554 and run the east paddock.
AS for fork lift motors. I got a towmotor cam for one of our LPG vans and it went from 15k / litre to 25k / litre and we never used 2nd gear again, sort of makes you think twice about conspiracy between engine makers & fuel companies
#10
7394
Yes I can relate to this, in the care of my 651V Kawasaki engine. And of course some that live near by.
7394
Being the old persnickety coot that I am, checking and adjusting the valves on my Kawasaki FH580V v-twin has become a routine maintenance task that I actually look forward to performing usually in late October when it's cool outside. The specs are for .004" to .006" on all 4 valves. I've been setting the lash at EXACTLY .004" gap on all the valves for the reason of taking advantage of the maximum lift and duration of the cam lobe profiles thereby allowing maximum power output, plus, I find that this makes the engine mechanically very quiet with quick reliable starting. If it's hot outside, the engine will even start without the choke. It's a 2007 engine on an Exmark with 548 hours of hard usage. I do some repair mower work on the side and I have noticed that so far, every machine I've worked on had never had the valve lash checked. One relative brought me his 3 year old Craftsman lawn tractor with a B&S 24HP V-twin for me to replace both belts. After replacing the belts, I wanted to do a quick test to make sure everything was correct and the engine was hard to start and idled poorly once up to temperature. Without telling him, I checked the lash and found all the valves were out of spec, some worse that others. The lash specs are exactly the same as my Kawasaki so I set all valves at exactly .004" and the engine's issues were completely resolved. When he came to pick of the machine, I deliberately did not mention the valve adjustment. About 3 days later he called me and asked why changing the belts has such a profound affect on making his engine run like new, BETTER THAN NEW. When I told him that I had adjusted the valves, he admitted that he didn't know valves needed adjusting. That seems to be the norm.
Yes I can relate to this, in the care of my 651V Kawasaki engine. And of course some that live near by.
#11
M
motoman
M
motoman
Maybe it is "torque" @ zero rpm. The point is that this sounds very strange, like something for nothing, but these electric motors do put out right at turn on, and before a full revolution. Better?