How to know when to get engine rebuild?

kx100getter
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kx100getter
Edited Date/Time 1/27/2012 4:29pm
Hi,

I have an 04 Kx100. I am just wondering the signs of when I need to replace something in the engine and what to replace. Also, what fails in the 2-stroke engine most often? I always hear like how people replaced the top end or whatever but I am wondering when they knew it was time to do this. Does it just seize up and that is how you know or does performance drop?

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williamsmotowerx 11/7/2010 2:51pm
11/7/2010 2:51pm
Every 25 hours on kx85, 100's piston change. Watch for Nicasil probs on intake bridge.

You can usually let cranks go until failure. More serious riders rebuild cranks once a season atleast.
kx100getter
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kx100getter 11/7/2010 2:54pm
11/7/2010 2:54pm
So, my bike could be only puttin out half power it normally does because I haven't changed anythin in the motor except spark plugs?
RACEGUY
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RACEGUY 11/7/2010 3:59pm
11/7/2010 3:59pm
Do a compression test (with the gauge I know you don't have) Pull the top end apart. Measure the cylinder (with the dial gauge you don't have). Measure the ring end gap (with the feeler gauges you don't have) and using the same non-existant gauge, measure the piston to cylinder wall clearance. Then, (with the vernier caliper you fon't have) measure the piston diameter.

Or....get an hourmeter and rebuild it every 25 to 30 hours like williams said above.
Craze
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Craze 11/8/2010 10:31am
11/8/2010 10:31am Edited Date/Time 11/8/2010 10:34am
LOL...He still hasn't fixed the shock yet !!!. Seriously, get a friggin owner's manual and follow it to a "T".......Then you'll know :p

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buggz
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buggz 11/8/2010 1:12pm
11/8/2010 1:12pm
williamsmotowerx wrote:
Every 25 hours on kx85, 100's piston change. Watch for Nicasil probs on intake bridge. You can usually let cranks go until failure. More serious riders...
Every 25 hours on kx85, 100's piston change. Watch for Nicasil probs on intake bridge.

You can usually let cranks go until failure. More serious riders rebuild cranks once a season atleast.
Is that for casual riding? How bout full on moto where the kid wrings it out quiet a bit
RACEGUY
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RACEGUY 11/8/2010 2:45pm
11/8/2010 2:45pm
buggz wrote:
Is that for casual riding? How bout full on moto where the kid wrings it out quiet a bit
It is a race bike. Therefore, everything is planned around it BEING RACED!! Hence, the term RACE bike. There is no one maintenance schedule for squids and another for real racers.
kx100getter
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kx100getter 11/8/2010 5:02pm
11/8/2010 5:02pm
I am probably not going to service anything until next March (unless something fails of course). Because I just don't have the money now and I still have to pay my dad like 400 dollars he loaned me to buy mx gear. I am going to get the top end rebuilt next March and the shock fixed and whatever needs to be fixed.
RACEGUY
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RACEGUY 11/8/2010 5:26pm
11/8/2010 5:26pm
Yeah, the bike knows you're low on cash, so it will wait until you're a litle better off before it breaks down.

I can see "cause and effect" isn't your strong point, but the whole idea behind regular maintenance is to catch things before they fail.

A worn ring today will catch in a port tomorrow and your simple piston and rings scheduled replacement becomes a cylinder and rod kit along with the piston and rings you could have stopped at in the first place.

Catastrophic failure is not waiting for you to get there...it's silently sneaking up behind you - with its hand out".
kx100getter
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kx100getter 11/8/2010 5:50pm
11/8/2010 5:50pm
No, I am saying the season is winding down and there are only a few more days at the track left till winter snows me in. I will save up over the winter and rebuild top end then. Like I said earlier though, I don't know how long it's been since it has been rebuilt because I have only had the bike 3 months. I may even have a mechanic look it over and check things out soon.
buggz
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buggz 11/8/2010 7:14pm
11/8/2010 7:14pm Edited Date/Time 11/8/2010 7:28pm
buggz wrote:
Is that for casual riding? How bout full on moto where the kid wrings it out quiet a bit
RACEGUY wrote:
It is a race bike. Therefore, everything is planned around it BEING RACED!! Hence, the term RACE bike. There is no one maintenance schedule for squids...
It is a race bike. Therefore, everything is planned around it BEING RACED!! Hence, the term RACE bike. There is no one maintenance schedule for squids and another for real racers.
There is no one maintenance schedule for squids and another for real racers.

Ya wanna Bet? I know 4 kids in the last year on the team that would get no where near 20 hrs out of a top-end


BTW I don't know any squids but there are some guys & girls that can get around on a dirt cycle pretty good. Other than that their just normal pepole
buggz
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buggz 11/8/2010 7:18pm
11/8/2010 7:18pm
kx100getter wrote:
No, I am saying the season is winding down and there are only a few more days at the track left till winter snows me in...
No, I am saying the season is winding down and there are only a few more days at the track left till winter snows me in. I will save up over the winter and rebuild top end then. Like I said earlier though, I don't know how long it's been since it has been rebuilt because I have only had the bike 3 months. I may even have a mechanic look it over and check things out soon.
Good for you ,do what you can afford. Save your money and take care of yer ride the best you can afford. And if the plating is looking bad? (which Kawi's are knowen for) get it sleeved, much more durable and you can bore it out.

Good Luck
kx100getter
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kx100getter 11/8/2010 8:41pm
11/8/2010 8:41pm
Sweet thanks. Wow, need top-end rebuild after less than 20 hrs?

That is like 2 long days at the track and then an engine rebuild???!!!???

Doesn't sound right to me.
nytsmaC
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nytsmaC 11/9/2010 9:50am
11/9/2010 9:50am
Get an hour meter.
xnationalwrench 11/9/2010 12:40pm
11/9/2010 12:40pm Edited Date/Time 11/9/2010 12:41pm
nytsmaC wrote:
Get an hour meter.
Have someone do a compression test (that's almost like a hour meter on a 2 stroke). And go from there, more than likely you will bne good till next year but you might want to freshen it up (new piston & rings) before next season.
Jujji
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Jujji 11/9/2010 2:15pm
11/9/2010 2:15pm
Good rule of thumb with a 2smoker is to do top ends once a year, if racing bump that up to 3 times a year. with a cylinder change every other.
haydos25
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haydos25 11/9/2010 7:04pm
11/9/2010 7:04pm
kx100getter wrote:
Sweet thanks. Wow, need top-end rebuild after less than 20 hrs? That is like 2 long days at the track and then an engine rebuild???!!!??? Doesn't...
Sweet thanks. Wow, need top-end rebuild after less than 20 hrs?

That is like 2 long days at the track and then an engine rebuild???!!!???

Doesn't sound right to me.
There is no way in the world that you would do 10 hours on the bike in a day at the track. You would be lucky do do 2 in a full day. Your bike is not running every minute you're at the track.

Get an hour metre, it'll shock you how little time you do.
DBerg
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DBerg 11/10/2010 9:44pm
11/10/2010 9:44pm
kx100getter wrote:
Sweet thanks. Wow, need top-end rebuild after less than 20 hrs? That is like 2 long days at the track and then an engine rebuild???!!!??? Doesn't...
Sweet thanks. Wow, need top-end rebuild after less than 20 hrs?

That is like 2 long days at the track and then an engine rebuild???!!!???

Doesn't sound right to me.
Dude, if you managed 10 hours of actual ride time in one day, you'd be a f'n machine. Figure around 2 min a lap, that's 300 laps... do that on back to back days and you sir would be the most gangsta rider in motocross
indy_maico
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indy_maico 11/11/2010 8:24am
11/11/2010 8:24am

How to know when to get engine rebuild?

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