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Cr250 loud bottom end burnout with clutch engaged


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Mike, being a prick comes naturally, but it is hard for people to give you assistance when they are unsure of what you are saying? I'm not sure what your problem with the clutch is; that it made a sound, but worked fine when you dumped it to intentionally spin the tire? Or perhaps you are saying that when you put it into gear, the clutch did not disengage with the lever in... yet upon inspection, everything on the clutch looked fine??? The reason you are not getting the answer(s) you seek, is because people don't know what the question is, because of your horrid use of the English language. So perhaps while this isn't English class, it might help to have taken one at some point in your life. Again, being a prick comes pretty easy for me, sorry, my cross to carry. ?

Hardhit - the little 80 is doing really well. I've been too lazy the past couple of evenings to finish jetting him. :baddaddy:

But the 14T front sprocket and FWW made him really good for riding/creeping along at idle .... and still has a nice wheelie-enducing snap when she gets into the powerband! :thumpsup:

Edited by 2strokes4me
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yeah, and i even thought the OP was doing clutch/tire burnouts and thats why i told him he wasnt taking care of the bike like he should. and now hes asking if the problem he is having is normal.

cool. i have the 80 aswell. still doing fine. just rebuilt the topend with 20-25 hours on the meter and not one single blowby color on the piston from top to bottom, above and under the ring. pretty nice.

whats yoiur jetting with the bike? altitude/temp and ratio?

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Hardhit - Stupid TT went into site maintenance while I typed up a novel and then clicked the reply button.

Nothing happened except the site consumed fifteen minutes of my life while displaying a "site maintenance" banner :mad-as-hell:

Anyhow, right now the jetting is stock (50 pilot, 125 main, needle on 3rd clip).

The float was 4mm too high, so I set it to the appropriate 19mm factory spec, to keep fuel from overflowing out of the carb.

The jetting is too lean down low, with the air/fuel screw set to about 1 turn out for best throttle response.

Its too rich up top on the pipe also and spooges more than normal.

FMF's website suggest a 55 pilot, 122 main, and 1-1/2 turns on the air screw for a 1996 ... but recommends a 52 pilot for all other years (97-02)???

I called to ask why, but all the guy could give me was a vague hunch, but no concrete answer for the discrepency.

Pro Circuits website suggests a 55 pilot, 122 main, and 1-3/4 turns out on the air screw, for ALL years (96-02); I'm leaning in that direction ...

Even though I have an FMF Fatty and FMF Shorty on the bike, I think I'll start with PC's specs and tune from there.

I mix Honda HP2 at 40:1, so I only have one fuel for all my bikes, and chainsaw if the need arises. :bonk:

Here in Western Washington the weather is pretty mild most the year (55-60°F), so I don't have to change jetting as necessity.

I prefer setting a bike up now while its cooler, 40-45°F, so when the temps climb, and the air thins some, the bike will run richer overall.

Never heard of a piston burning up from lack of heat, so rich is better than lean.

If I set a bike up in the peak of summer (85°F) it would then be too lean for this time of year.

I prefer to adjust the air/fuel screw a little for climates/elevation, rather than rejetting the carb with seasonal changes.

My house sits at about 500' above sea, but I will ride anywhere from sea level up to a few thousand feet, so my changes overall are not drastic.

I wish I had more time in my life to jet, but site maintenance has been cutting into that time lately. ?

Anyhow, what is your jetting specs for your 80, and what area do you live in, etc?

Sorry for the thread jack, Mike ... just being a jerk again.?

Edited by 2strokes4me
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good right up.

i understand the frustration about wasting 15min of writing only to have the site matained. yep done that. only in my case i accidentally click back arrow on the internet.

im at cold winter right now at sea level.

jet my bike for 25:1

PJ: 45

MJ: 117

needle at 3rd

float: i dont know. its been there since i got it but i never had a leakage nor surge, no need adjustment.

bike has all original pipe and silencer. looks brand new for an 01 pipe. no dings whatsoever. only mod to it is boyesen power reeds.

I had a friend of mine test rode my bike and topld him to be careful but jokely, told him to crack the throttle. funny as you already guessed, he cracked the throttle and the next time he knew, he was on his back on the ground.

cant believe how much me and the others laughed at him.

i also lend teh bike to a friend and he was riding through whoops very carefully. he suddenly lost control and he went down but the bike did flew 360 degrees and continued to roll a few meters away.

never underestimate the cr80. looks can be VERY decieving.

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Yeah, I'm too large for the bike (6'3" 220lb), but it is still fun to ride ... a little rocket-ship when that powerband hits, lol!

I'm suprised your jets are as lean as they are, considering you mix a lot of oil (25:1) ...

Naturally there is less fuel per gallon in that mix ... so fewer fuel molecules are pulled thru your jets per a given engine cycle.

You also could have a more humid climate, so there are fewer air molecules per cycle also, which would make sense?

Its amazing how varied jetting can be for the "same" bikes.

I've heard of guys changing their pilot jets from a 35 down to a 17, and all kinds of wild stuff.

You would think the machining and climates wouldn't make that much difference, but they do!

Anyhow, Mike probably wants to punch me in the bridge of my nose by now, lol. :bonk:

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haha yeah. hey mike. hows the bike doing anyway? yous dont mind me and 2stroke here have other conversasion would you lol.

anyhow. i know it seems lean but for some reason, plug is black and wet on the threads of the spark plug and black or a combination of brown in the center part. but very dry on the center. no white or grey color nor metalic sparkle particles of some sort.

no spooge other than dry black when i stick my finger inside the silencer. and very liitle smoke. almost invisible.

for some reason, the piston is wet with premix and no blow by at the top of the rings and below the rings on the entire front section of the piston when looking at the exhaust side. no scratch but do have a tiny bit of normal wear at the very edge of the skirt below.

all this with 20-25 hours from rebuild.

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Sorry im useing my phone desktop needs a hard drive it is a bike I bought just needed a top end the issue was as soon as I clicked into first from idle it was just acting as tho the clutch was not engaged and just started to spin the rear tire and it was making a grinding noise the only thing that I noticed was the primary gear having a little bit of play in it how much actuation should there be when you are looking at the clutch discs the closest ones to the motor dont really look like they are pulling apart at all but the outer ones pull appart further thats normal right

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Sorry im useing my phone desktop needs a hard drive it is a bike I bought just needed a top end the issue was as soon as I clicked into first from idle it was just acting as tho the clutch was not engaged and just started to spin the rear tire and it was making a grinding noise the only thing that I noticed was the primary gear having a little bit of play in it how much actuation should there be when you are looking at the clutch discs the closest ones to the motor dont really look like they are pulling apart at all but the outer ones pull appart further thats normal right

I would not start the bike again, there should be no need to. You may have more than one problem. So you just got the Bike as is?

You should have about an 1/8" of play in your clutch cable until you start to feel the resistance, is this what you have?

As far as looking at the clutch disks during actuation, that is normal due to the oil causing some of the disks to stick together.

As far as the grinding noise coming from the clutch area, put the bike on a stand

You should also drain the oil in a very clean white container and check for metal, always expect a very thin film floating on top for normal clutch wear. you just don't want to see any bits of metal falling to the bottom of the container.

Rotate the clutch basket with your hand and feel for any loose bearings or any thing out of the ordinary. Do this in and out of gear. Take the head off and check for any severe back lash up to the point that the piston starts to move.

All gears have a very small amount of back lash, that is normal.

Good luck, keep in touch and post what you find

Edited by AXAxiom
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