Engine rebuilds

[Honda_Power]

Why do you people insist on rebuilding your damn motors after ever freakin' ride?  My gawd, these motors can go for probably 100,000 miles easily if taken good care of....... I'm sure there's enough R&D that goes into it to make these dirtbike motors reliable before they release and sell it to the public.  I swear, you people are out of control and out of your minds with your constant rebuilds after every 2-3 hours.

Edited May 14, 2014 by Honda_Power

[Still Bill]

I hear what you are saying; however, replacing a 2-stroke piston BEFORE it goes bad saves money in the long run.

[RLTrail]

Hmmm.

Edited May 14, 2014 by RLTrail

[Tony211]

I aim for 40-50 hours on a piston on my YZ250 smoker. 200$ could save me lots, and why not?

Maybe these people are rich, so what's the big deal?

[Honda_Power]

I aim for 40-50 hours on a piston on my YZ250 smoker. 200$ could save me lots, and why not?

Maybe these people are rich, so what's the big deal?

It's just you guys make it seem like these dirtbike motors are as fragile as the boy in a bubble and can explode at a moments notice like Alec Baldwin around papparazi's. 

 

Like I said, these motors have been R&D'd and well tested (in motocross conditions) before being sold to the masses....... so I'm sure they are more then reliable to last more then 2 outings without your itchy hands wanting to rebuild them.  In fact by "rebuilding" it in your little shack, you probably lessened the life of the motor (no quality control).  

 

Just saying, not trolling.

Edited May 14, 2014 by Honda_Power

[youngztr]

The OP doesn’t know the difference between the engines in his Civic vs lawn mower vs margarita mixer….

 

Or maybe the OP is imbibing in too many home brewed margaritas mix with his lawn mower?

[ktmhunt]

So what you are saying is that you can a dirt bike 100,000s of thousands of miles. If so then you are sadly mistaken. The most i have gotten out of a bike 8,200 miles before i felt like it needed one.

[Fatt_Tones]

 

In fact by "rebuilding" it in your little shack, you probably lessened the life of the motor (no quality control).  

 

 

If that isn't trolling, it's by far one of the most ignorant statements I have read on here...

[Fatt_Tones]

In the interest of quality control, I like to employ the individual with the most vested interest in MY bike.  That's ME, the guy riding it......

[Honda_Power]

If that isn't trolling, it's by far one of the most ignorant statements I have read on here...

How's that trolling?  I'd much rather trust factory building their own motors, having to pass through rigorous inspections and pass specifications......... then "Bubba" putting together my motor while just 'eye-balling' everything and saying to himself, "Hmmm..... looks close enough to me".

[zotis777]

Youre a troll. We're dirt bike enthusiast, you have an ENTIRE rest of the internet to troll.....

[not_again]

You are either a F'in retard or a... well maybe you are just stupid. In that case, let me educate you. There is a well documented amount of run time possible before a rebuild on most bike engines, whether it's a CRF, a YZ, a DRZ, a Ducati, or a Harley. Doesn't matter what kind of bike motor it is. 

 

Let me give you a slightly unrelated analogy to prove my point: One of my friends had a very worn, very tired Kawasaki 636 street bike. It was never raced, just commuted and driven spiritedly. It had every oil change documented at 2,000 miles, air filter cleaned ever 500-1000. No repair work done to it ever, just very basic service. This bike was smoking and losing oil out of the exhaust it was so worn. The timing chain rattled. The pistons slapped. The valves clattered. It had 45,000 miles. This is a bike designed to run many lifetimes longer than a modern dirtbike motor and yet it lasted many lifetimes less than a modern car engine. You need to quit comparing performance bike engines to car engines, they aren't similar at all.

 

What is very different with current high performace 4 stroke engines is the shape of the piston. They have a very short skirt and will flip over in the bore if allowed to wear too much. Obviously this causes complete engine destruction.

Honda recommends a new piston every 15 hours in a CRF250 and 450. You think they designed the motor to run 100,000 miles before major repairs? They designed it to run 500 miles.

 

Now most everyone I know doesn't swap out a piston at 15 hours, 50 to 150 is considered a good range depending on use. Crankshafts at 200-800 also depending. The object here is to not have the engine blow up. Which it will, unless you spend a relatively small amount of $ on service parts.

 

Starting to make sense now?

[youngztr]

So, you were the one giving Baldwin a BJ when he exploded around the Papparazi….  Post up some pics!!!!  Maybe we can get some tips on how to keep our heads from exploding too soon.

[ScootMcGoot]

There is absolutely no way any dirt bike would last 100,000 miles. It just won't. That being said I can agree that some people are a little over zealous with the engine rebuilds. I know a guy who is a 250B woods rider on a 250 smoker. He insisted on getting his engine rebuilt this year before the season started with under 20 hours on the meter. I am all for preventative top ends but under 20 hours!!! Really??? My 4 stroke I do new pistons every 100-130 hours. On the 2 stroke 60-80 will probably be my threshold.

[Honda_Power]

You are either a F'in retard or a... well maybe you are just stupid. In that case, let me educate you. There is a well documented amount of run time possible before a rebuild on most bike engines, whether it's a CRF, a YZ, a DRZ, a Ducati, or a Harley. Doesn't matter what kind of bike motor it is. 

 

Let me give you a slightly unrelated analogy to prove my point: One of my friends had a very worn, very tired Kawasaki 636 street bike. It was never raced, just commuted and driven spiritedly. It had every oil change documented at 2,000 miles, air filter cleaned ever 500-1000. No repair work done to it ever, just very basic service. This bike was smoking and losing oil out of the exhaust it was so worn. The timing chain rattled. The pistons slapped. The valves clattered. It had 45,000 miles. This is a bike designed to run many lifetimes longer than a modern dirtbike motor and yet it lasted many lifetimes less than a modern car engine. You need to quit comparing performance bike engines to car engines, they aren't similar at all.

 

What is very different with current high performace 4 stroke engines is the shape of the piston. They have a very short skirt and will flip over in the bore if allowed to wear too much. Obviously this causes complete engine destruction.

Honda recommends a new piston every 15 hours in a CRF250 and 450. You think they designed the motor to run 100,000 miles before major repairs? They designed it to run 500 miles.

 

Now most everyone I know doesn't swap out a piston at 15 hours, 50 to 150 is considered a good range depending on use. Crankshafts at 200-800 also depending. The object here is to not have the engine blow up. Which it will, unless you spend a relatively small amount of $ on service parts.

 

Starting to make sense now?

Are you saying the Honda S2000 (2.0 Litre, 4 cyclinder, 147 horsepower, 9,200 rpm redline, 11.7:1 compression ratio) is not a 'performance' motor?  It's actually a race inspired motor meant to be driven in the high RPM's..........AND it's a production motor off the assembly line too, and probably capable of going over 300,000 miles easily without a rebuild if taken care of properly with regular maintenance.

 

Honda #1....... over 120 horsepower per litre out of a 4 cylinder naturally aspirated!  Name me who else can do production motors like that?  And mind you.... this was 15 years ago!

 

Honda the best!

Edited May 14, 2014 by Honda_Power

[FUDad]

You are either a F'in retard or a... well maybe you are just stupid. In that case, let me educate you. There is a well documented amount of run time possible before a rebuild on most bike engines, whether it's a CRF, a YZ, a DRZ, a Ducati, or a Harley. Doesn't matter what kind of bike motor it is.

Let me give you a slightly unrelated analogy to prove my point: One of my friends had a very worn, very tired Kawasaki 636 street bike. It was never raced, just commuted and driven spiritedly. It had every oil change documented at 2,000 miles, air filter cleaned ever 500-1000. No repair work done to it ever, just very basic service. This bike was smoking and losing oil out of the exhaust it was so worn. The timing chain rattled. The pistons slapped. The valves clattered. It had 45,000 miles. This is a bike designed to run many lifetimes longer than a modern dirtbike motor and yet it lasted many lifetimes less than a modern car engine. You need to quit comparing performance bike engines to car engines, they aren't similar at all.

What is very different with current high performace 4 stroke engines is the shape of the piston. They have a very short skirt and will flip over in the bore if allowed to wear too much. Obviously this causes complete engine destruction.

Honda recommends a new piston every 15 hours in a CRF250 and 450. You think they designed the motor to run 100,000 miles before major repairs? They designed it to run 500 miles.

Now most everyone I know doesn't swap out a piston at 15 hours, 50 to 150 is considered a good range depending on use. Crankshafts at 200-800 also depending. The object here is to not have the engine blow up. Which it will, unless you spend a relatively small amount of $ on service parts.

Starting to make sense now?

I like you, so I hate to see you fall into this troll trap. This guy started four. different troll threads yesterday, and he's not even funny.

[Wild Alaskan]

Why do you people insist on rebuilding your damn motors after ever freakin' ride?  My gawd, these motors can go for probably 100,000 miles easily if taken good care of....... I'm sure there's enough R&D that goes into it to make these dirtbike motors reliable before they release and sell it to the public.  I swear, you people are out of control and out of your minds with your constant rebuilds after every 2-3 hours.

 

I've got a an entire box of parts that say there is a lot that can go wrong inside a dirt bike motor if its not maintained.

 

Are you saying the Honda S2000 (2.0 Litre, 4 cyclinder, 147 horsepower, 9,200 rpm redline, 11.7:1 compression ratio) is not a 'performance' motor?  It's actually a race inspired motor meant to be driven in the high RPM's..........AND it's a production motor off the assembly line too, and probably capable of going over 300,000 miles easily without a rebuild if taken care of properly with regular maintenance.

 

Honda #1....... over 120 horsepower per litre out of a 4 cylinder naturally aspirated!  Name me who else can do production motors like that?  And mind you.... this was 15 years ago!

 

Honda the best!

 

sure thats a high preformance motor and it gets ridden at a avgerage of maybe 10%of its potential its entire life, no doubt it will last longer than a 125 being held wide open all day. 

 

120hp per liter isn't anything new or insane, even 10 years ago...

[cynicryder]

ok, so 120HP/liter run at 10% and 180-190F water temp in clean air  vs 140HP/liter (CRF250) run at 80% and 240-260F water temp in he dirtiest envrionment.... I wonder which one lasts longer, 

[The Spanky]

Why do you people insist on rebuilding your damn motors after ever freakin' ride?  My gawd, these motors can go for probably 100,000 miles easily if taken good care of....... I'm sure there's enough R&D that goes into it to make these dirtbike motors reliable before they release and sell it to the public.  I swear, you people are out of control and out of your minds with your constant rebuilds after every 2-3 hours.

 

You have no idea what you're talking about.

 

These are competition engines that are designed for performance and light weight, not longevity.

 

Drive your car at redline and full throttle all the time, everywhere you go, and then get back to us with how long the engine lasts. I'll bet you it won't be anywhere near 100,000 miles.

 

Go ahead and try to run whatever bike you ride for 100,000 miles. I dare you.

 

When I replace the piston and rings in my KX250 at around 40-45 hours, the piston will just barely still be in spec.

 

Top Fuel dragster engines run for less than a minute per race, and are completely shot at the end of that time period.

[KJ790]

He's owned a bike for a week, he obviously has figured out everything there is to know...