questions on my new kx250f PICS INCL

[socalidol]

Thanks for taking a look,

I would really appreciate any and all comments, short or long

I also appreciate any of you able to make it thru this entire novel.

 

i have been around on this fourum for a bit, however it was a year ago and forgot my login info, so this is my new one..

 

Anyway, Ive always had 2-strokes my whole life, and rode my friends crf450 and immediately wanted to get a 4 stroke.

 

So here it is, Its not fantastic by anymeans,

 2007 Kx250f

full fmf

protaper triple

some weird green rims, (I dont hate them)

some sort of holeshot device on the fork

 

Im a novice, yes i have been riding for 12 years, so i can easily hop on any bike and ride it but not a pro by any stretch,

I have owned a few yz125s and 250s (2strokes)

 

here are a couple questions I have on this bike

 

previous owner was not a kid, or abuser who was irresponsible, but he did seem like he was a hard rider, however did keep up on common maintenance after each ride.

 

The main issue I need to fix before I can do any serious riding is i need a new or rebuild Rear brake master cylinder.. previous owner said I could find a used one off preferrably a newer kx250f instead of buying new, or I could rebuild the one i have I think i have the body for it,, I also do have the line too all is disconnected, the pin is barely or not even touching the disc when rolling. heres a pic

 

 

What should I do on this? If its not too much more expensive (and as a novice mechanic as well) on a scale of 1-10 how difficult is this project, assuming i could find some videos on youtube, I think i can manage, should i rebuild? just buy a new one? I believe new its like $2xx.00 or so, and used on ebay less than $20-$50 or is it tricky enough to need to use one of my mechanics in the area (not with a company, hes very affordable) just a hassle to take it over.

 

next is the throttle seems to stick a little, the previous owner said i should lube the throttle cable, is this the usual suspect to that, or is it the throttle tube? he put on new grips recently so I am assuming the tube isnt too bad, if lubing the throttle cable is the answer, im sure that is easier to find online as a tutorial, or is that something pointless and I should just buy a new one..

 

I have noticed the Kick start lever does have a bit too much play only when in the upright position after starting, i can easily move it to where when in the up position, it can wiggle and rattle against the frame.. what should i do there, just put some soft foamy tape against the frame in that 2 inch section and leave it be? or is it something needing to be fixed asap

compression is really good, starts up easily

 

When I fired it up today, i smelled a scent that seemed like a burning smell, definitly noticable, does have me worried, I looked down and where the pipe comes around the rad, it was red from how hot it was, (within 2 minutes of being started up, not riding, just idling letting it warm up) I know these pipes get hot, but should it turn red like an iron in the fire? scared me a little too..

 

lets see.. whats next..

lastly, when starting it up today, and riding very briefly yesterday as a test ride (yes with no rear brake) it did do some backfiring (not often, but a couple times) and today i did notice some very very brief Flames coming out for that split second flash.. googles that and seems its not too uncommon, please let me know what to do on that too.

 

as a first time 4stroke owner, I think ive heard usually the most expensive thing to fix is the valves or reeds or something my buddy was saying.. DOES ANY OF THE ABOVE ISSUES SEEM LIKE THAT COULD BE THE CASE?

if so, i may take it to my private mech to do a rehaul

 

 

I am in process of a full cosmetic facelift.. usually the first thing I do on any bike I buy to make it mine,

I live in Corona CA, so i today I had the luxury of walking into procircuit today check out the showroom, and check things like my kick start lever, etc..

 

 

overall, the bike runs pretty well, it idles good, the clutch seems very good and tight, seems very quick, I dont really know what to compare it to other than my 2 strokes, even with these issues I think i have a new favorite bike.

 

 

well seems as though I have my hands full on doing some fixin' (which i dont mind at all I kinda enjoy (it the issues i can fix that is)), however being unknowledgable and somewhat uncapeable on some of these issues stresses me out and I really value the advice and opnions of you all on here, i read everything i can, and really really appreciate any advice you can give me.

 

 

heres your kids future competition haha thanks again for reading and feedback

[mastera210]

Thanks for taking a look,

I would really appreciate any and all comments, short or long

I also appreciate any of you able to make it thru this entire novel.

 

i have been around on this fourum for a bit, however it was a year ago and forgot my login info, so this is my new one..

 

Anyway, Ive always had 2-strokes my whole life, and rode my friends crf450 and immediately wanted to get a 4 stroke.

 

So here it is, Its not fantastic by anymeans,

 2007 Kx250f

full fmf

protaper triple

some weird green rims, (I dont hate them)

some sort of holeshot device on the fork

 

Im a novice, yes i have been riding for 12 years, so i can easily hop on any bike and ride it but not a pro by any stretch,

I have owned a few yz125s and 250s (2strokes)

 

here are a couple questions I have on this bike

 

previous owner was not a kid, or abuser who was irresponsible, but he did seem like he was a hard rider, however did keep up on common maintenance after each ride.

 

The main issue I need to fix before I can do any serious riding is i need a new or rebuild Rear brake master cylinder.. previous owner said I could find a used one off preferrably a newer kx250f instead of buying new, or I could rebuild the one i have I think i have the body for it,, I also do have the line too all is disconnected, the pin is barely or not even touching the disc when rolling. heres a pic

 

 

What should I do on this? If its not too much more expensive (and as a novice mechanic as well) on a scale of 1-10 how difficult is this project, assuming i could find some videos on youtube, I think i can manage, should i rebuild? just buy a new one? I believe new its like $2xx.00 or so, and used on ebay less than $20-$50 or is it tricky enough to need to use one of my mechanics in the area (not with a company, hes very affordable) just a hassle to take it over.

 

next is the throttle seems to stick a little, the previous owner said i should lube the throttle cable, is this the usual suspect to that, or is it the throttle tube? he put on new grips recently so I am assuming the tube isnt too bad, if lubing the throttle cable is the answer, im sure that is easier to find online as a tutorial, or is that something pointless and I should just buy a new one..

 

I have noticed the Kick start lever does have a bit too much play only when in the upright position after starting, i can easily move it to where when in the up position, it can wiggle and rattle against the frame.. what should i do there, just put some soft foamy tape against the frame in that 2 inch section and leave it be? or is it something needing to be fixed asap

compression is really good, starts up easily

 

When I fired it up today, i smelled a scent that seemed like a burning smell, definitly noticable, does have me worried, I looked down and where the pipe comes around the rad, it was red from how hot it was, (within 2 minutes of being started up, not riding, just idling letting it warm up) I know these pipes get hot, but should it turn red like an iron in the fire? scared me a little too..

 

lets see.. whats next..

lastly, when starting it up today, and riding very briefly yesterday as a test ride (yes with no rear brake) it did do some backfiring (not often, but a couple times) and today i did notice some very very brief Flames coming out for that split second flash.. googles that and seems its not too uncommon, please let me know what to do on that too.

 

as a first time 4stroke owner, I think ive heard usually the most expensive thing to fix is the valves or reeds or something my buddy was saying.. DOES ANY OF THE ABOVE ISSUES SEEM LIKE THAT COULD BE THE CASE?

if so, i may take it to my private mech to do a rehaul

 

 

I am in process of a full cosmetic facelift.. usually the first thing I do on any bike I buy to make it mine,

I live in Corona CA, so i today I had the luxury of walking into procircuit today check out the showroom, and check things like my kick start lever, etc..

 

 

overall, the bike runs pretty well, it idles good, the clutch seems very good and tight, seems very quick, I dont really know what to compare it to other than my 2 strokes, even with these issues I think i have a new favorite bike.

 

 

well seems as though I have my hands full on doing some fixin' (which i dont mind at all I kinda enjoy (it the issues i can fix that is)), however being unknowledgable and somewhat uncapeable on some of these issues stresses me out and I really value the advice and opnions of you all on here, i read everything i can, and really really appreciate any advice you can give me.

 

 

heres your kids future competition haha thanks again for reading and feedback

Just get rebuild kit all it is a seal some orings one circlip holds it remove clip clean replace rubber parts back to gether bleeding it is the pain

 

Cables wear inside you cant see it so new cables make sure grip is not rubbing housing

 

All alum kick starter get slop in them the only thing you can do get new one not cheap!

 

Now these new 4 strokes 1 they run HOT yes pipe will turn red in florida to ride enduros you have to wrap pipe had one guy fall in high grass and started a fire! Yes they all will pop somethimes and flames out muffler thats why you have to have spark arrester in H/S or Enduros or any trails.

[The_Vernsker]

To fix the brake u should just buy the rebuild kit. Take everything apart keeping track of how it goes together and then replace the worn parts with all the new ones included in the kit. Bleeding this brake may be a pain, but we can give you some pointers once you get to that step.

To fix the throttle issue I would start by removing the throttle tube and cleaning it and the handle bar. Don't put any lube between them, just get them 100% dirt and lube free and it will work better. If that doesn't do the trick replace the throttle cable(s).

When u start the bike and it gets red hot quickly you know the bike is jetted improperly. I rode my 07 kx250f in 100+ heat during the summer and the pipe never got red hot. I never had poping issues either. I would have to say your bike us running lean with the needle in the wrong position.

[Dragon67]

the only time I ever had a KX250F with those symptoms it was due to air leaks.  The head pipe needs to be sealed to the head and it also has to be sealed at the mid-pipe.  Why it gets so hot when not sealed is simple.  When air is introduced into the system, combustion takes place in the pipe.  Hot, unburned gas + oxygen + hot pipe = combustion, which equals hotter pipe and more combustion and flames out the back end.  You have an aftermarket header.  It is not sealed properly.  That is your issue.

 

For the kickstart, you may be able to get it tighter by inspecting the spring and ball bearing that keeps it in place.  Sounds like the ball bearing or spring may be gone.  There are lots of ways to fix the kickstart if it is sloppy.  Check back if you want more info.

[socalidol]

the only time I ever had a KX250F with those symptoms it was due to air leaks. The head pipe needs to be sealed to the head and it also has to be sealed at the mid-pipe. Why it gets so hot when not sealed is simple. When air is introduced into the system, combustion takes place in the pipe. Hot, unburned gas + oxygen + hot pipe = combustion, which equals hotter pipe and more combustion and flames out the back end. You have an aftermarket header. It is not sealed properly. That is your issue.

For the kickstart, you may be able to get it tighter by inspecting the spring and ball bearing that keeps it in place. Sounds like the ball bearing or spring may be gone. There are lots of ways to fix the kickstart if it is sloppy. Check back if you want more info.

Ok thanks, I did notice that the header pipe or whatever after the bend, where it meets the other pipe I think, right near where the engine is the straighter piece, I am able to twist it like it is not 100 percent tight and snug so that is I'm hoping the issue of it getting red hot, am I damaging it by fixing that down the road, if these bikes run hot anyways.. Here's a pic of where the mid pipe has a bad connection between the head and muffler it's loose and can twist

Also here's a pic of some heat scars I think, it can't be cleaned off like dirt

[notoriousE-R-I-C]

Id get a new copper header gasket and put a high temp silicone like hondabond around the header at the midpipe joint to help seal it.

I agree with mastera210 and rebuild your master.

And you can always loop a ziptie loosely to hold your kickstart! But Dragon knows his stuff so check the bottom of the actual lever.

Cool bike. I like the rims

EZ

[socalidol]

Id get a new copper header gasket and put a high temp silicone like hondabond around the header at the midpipe joint to help seal it.

I agree with mastera210 and rebuild your master.

And you can always loop a ziptie loosely to hold your kickstart! But Dragon knows his stuff so check the bottom of the actual lever.

Cool bike. I like the rims

EZ

Thanks I'll be putting some hours in this week

Trade ya for some black rims lol

[notoriousE-R-I-C]

Haha! I got regular aluminum DIDs. I heard blacks look bad after time. Get dirty fast. I dunno those are alright. Seeing them in person may be different. I like em. Just dont spray paint em!