Couple blaster issues

Facinus

New Member
Jan 19, 2010
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I had to hone out my cylinder and put in a new piston. So i got it all back together the other night. Anyway, I don't have a garage to keep it in, so its been outside in the cold (under a tarp) but I think maybe some water got in somewhere and froze up. I can't get it started. It has compression and spark. It started a few times but only for like a seconds each time.

When it's in neutral you can push it around fine but when its in first gear with the clutch pulled in its got a lot of resistance to push it around.

Second, gas is like flowing out of a tube which comes from the carburetor, not sure why that is?


Thanks guys
 
when it started. did it rev when you hit the gas? 2. overflow in the carb-float bowl adjustment. 1. drag when the clutch is pulled-sounds like the clutch basket. how are you starting it??? cold weather? full choke-dont hit the throttle when you try to kick it over. did it run before the hone?
 
I didn't have a chance to hit the gas when it started. It was literally 1 second lol.

Yeah its cold weather here still. in the 20s. I'm going full choke and not hitting the gas when i try to.

It ran before the hone, but the reason I had to hone it was something had gotten in the cylinder and scarred the side.
 
first adjust the float for the fuel problem: take your carb off and clean it good



Overview: Jetting 101

Carburetor fuel circuits and functions:

1) Pilot jet/slow jet - Affects mixture from idle to 1/3 throttle opening. The pilot jet meters fuel to the "bottom end circuits"

2) Air screw - Meters air to pilot jet. It is usually located near the back or air box side of the carb. Turning in clockwise, will richen the pilot mixture. Turning out, counter clockwise, will lean out the pilot mixture. Average setting for most 2 strokes is 1 to 2 1/2 turns out. Refer to owner's manual.

Note: If the adjustment screw is in the front of the carb, it is a fuel screw and not an air screw; it is adjusted the opposite of the air screw. Most 4-strokes are this way.

3) Jet needle aka Needle - Affects the mixture from 1/4 throttle to full throttle. The needle is in the leanest position when the clip is on the top, and richest on the bottom. The needle calibrates the full to the change in throttle valve (slide) opening. The further down the needle is, the later the main jet comes on and the leaner the mixture at that point.

4) Main Jet - This circuit affects the mixture from 1/2 throttle to full throttle. This is your full blast top end circuit. This circuit is most accurately tuned by checking the plug for the correct color, sort of mocha brown.

5) Float/Float valve/Float level - Your owner's manual has the correct level and procedure for calibrating your bike. Here are some symptoms that would indicate the need for float adjustment.

A) If float level is too high, the float bowl overflows out the drain hoses, and fuel often blocks the air passages that allow the carb to de-pressurize. This causes a bog, or hiccup over large hits.

If float level is too low, the engine starves for fuel off idle, causing a "boooooowang" sound very similar to a pilot jet or air screw set too lean.

Jetting Guidelines; Eliminating the variables.

1) Never change more than one circuit at a time. You need this tool to tell you exactly which circuit is affecting performance and at what throttle opening.

2) Use fresh gas. Octane ratings diminish with time and the higher the octane the slower the burn and richer the mixture. The quality of today’s pump gas is decreasing. To compensate for the fuel, richer jets are required. Also note that fuel with ethanol (aka MTBE) also requires a slightly richer mixture.

3) Always start with a fresh air filter. Let a freshly oiled air filter dry at least 6 hours in advance so that the alcohol in the air filter can evaporate. Then match the carb to a motor that breathes properly. Otherwise, the engine will run slightly leaner when the clean air filter is installed.

4) When performing a plug check, use a good used spark plug. New plugs are white and are hard to read accurately for mixture checks. If you have to use a new plug be sure to put at least 15 to 20 hard minutes on it before attempting to get a reading.

5) Always check for clogged carb vent lines. Clogged lines will cause hard starting and bogging when the motor is hot. They can also cause erratic running that seems to mimic a mis-adjusted float, but worse. Performance will seem rich and acceleration will be sluggish off idle.

6) If you’re trying to track down a jetting problem, don’t change your premix oil brand or the ratio. The pre-mix ratio will determine how much fuel is available to be burned because the oil isn’t burned, and in terms of liquid volume, the oil takes up a portion of the liquid (oil + fuel). While the ratio will have a minimal impact when making small changes, remember that you’re trying to eliminate variables.

How to Jet

1) Mark your throttle housing and grip in 1/4 turn increments. Use a marker, razor blade, etc.

2) Now get the motor to operating temperature by riding around, away from the pits.

3) Once the motor is warm, ride in 2nd and 3rd gear from the low RPM to high RPM. This puts a good load on the motor and is an accurate test of performance.

* try to notice if the problem gets worse or better as the motor heats up.

4) Now try to locate the throttle opening at which the problem exists. See details just below.

Rich Jetting Symptoms and Solutions

A) Motor won’t idle and idle set screw is ineffective. Try leaning out the air screw by turning it counter clockwise a quarter turn at a time. If the air screw has no effect, install a leaner pilot jet and return the air screw to 1 turn out. Proper air screw settings are usually between 1 and 2 1/2 turns out. The correct pilot for your bike is one that allows instant off-idle throttle response, and allows the air screw to be effective between 1 and 2.5 turns out. If the problem still exists, check and clean the choke circuit and carb vent lines.

Motor stumbles off idle to 1/2 throttle, then cleans up. If everything in part A above is correct, check the needle. Stock position is usually in the middle, but check your owner’s manual to be sure. To lean out the needle, you need to raise the clip. If the needle is dropped all the way lean and problem still exists, try a leaner needle.

C. Motor will rev through the mid range then becomes gurgley (technical term) at full throttle and power is sluggish. This is a text book example of a rich main jet. This problem often occurs when an air filter becomes clogged and gets worse as the motor heats up. Choose a main jet with a smaller number and lean out the air fuel mixture one step at a time. If the problem still persists even though it’s improved a little, reinstall your original main jet and lean out the needle one position. Now fine tune the main jet with plug checks.

Plug checks are the key to fine tuning the main jet once the other circuits are set.

White Porcelain Chocolate Mocha Brown Black/Wet

Lean Perfect! Rich

Look for symmetrical burn patterns, smell for odors like burnt plastic, which is actually tranny fluid and would be indicative of a blown seal.

Lean Jetting Symptoms and Solutions

A) Motor hesitates off idle with a "Boooooooooowang" sound. This is a lean symptom and often occurs when a motor is cold. Try turning the air-fuel screw clockwise a quarter turn richer and check throttle response again until motor revs without hesitation. If the motor "hangs up" or doesn’t come right back down to idle, install a richer pilot, and reset air screw.

Motor knock knock knocks at idle when hot. Try solution A. If problem persists, perform a "leakdown pressure test" to check for ignition crank seal leakage.

C) Motor revs clean and crisp but runs really hot and lacks power. This symptom indicates a lean main jet and/or needle. Use a richer main jet and/or needle setting. This is the most common misconception about two stroke jetting: When a motor runs excessively hot and lacks power, it is on the verge of seizing. If you are on the trail and don’t have the right main jet, try raising the needle by lowering the clip. It won’t be exact but at least you won’t seize.

Note: To be certain that your problem is lean, pull on the choke and see if the problem gets better or worse. If better, your problem is a lean condition.

Thanks randelator!!!!



then adjust your clutch:

clutch adjustment by awk..........here we go again, lucky im just copy and pastin this............... it took me 4 or 5 times to get this right, very frustrating, do all this with the cable disconnected at the hand lever so it doesnt effect the internal adjustment, open her up, again!!!, loosen the locknut and screw, back it out a little, (the adjustment shaft in the middle of the clutch basket) then where the cable connects to the motor lever,theres a notch that lines up, look on the engine lever for the little point and a mark on the case, line these up, make sure it doesnt move while adjusting, a freind would be good here, then move to the other side, tighten the rod in with a small straight screwdriver till you feel it touch, then i think i read somewhere to back it off 1/2 a turn,then tighten the locknut, <<<<definately use locktite here, mine almost came loose, and thats disaster, then reconnect the cable to the hand lever, and adjust your slack i also did this with the wheels off the ground, so i could spin them with the clutch lever pulled in,to see if the wheels spun free, or if there was engine lag as i released it, before i put it all back together

check your reeds to see if they are cracked or broke.....make sure your getting fuel to the plug
 
Aight so here's what happened. I opened up the carb and it all looked good. Put it all back on and the gas flow problem stopped. Guess something was stuck.

I took off the head to check the cylinder (it was on right :p) and then put it back on tested compression (fine) and spark plug (fine) I still had my exhaust off and my dad had come outside so i kicked it and it sounded different. So i put everything back on and it started on the first kick.

I broke it in slow and then after a bit was cruising down the road and it slowly died. We pushed it back to the house and found the same problem which I originally had to change the piston for. The exhaust side is all scarred up. My dad said I should have changed my oil. Luckily this time I can just hone the cylinder and get new rings, and dont need a whole new piston.
 
um. you know the oil goes in with the gas right. not to be smartassed. just reffering to your comment about changing the oil. the piston you took out earlier...was it broken as in did it have pieces missing? somethings not right if its still scarring your cylinder wall? did it make any strange noises before it completly stopped? pinging maybe? figure out whats up before you start it again or you'll be wasting your time?
 
when you take the cylinder off check to see if the connecting rod has any sideways play in it. like more than a millimeter or so. move it around its cycle to see if it feels smooth. does it have the oil injection system on it???
 
um. you know the oil goes in with the gas right. not to be smartassed. just reffering to your comment about changing the oil.
Yes. I mix 40:1 usually. My dad says the oil already in there should be changed because its most likely got some grit or something in it.
the piston you took out earlier...was it broken as in did it have pieces missing?
Near the top of the cylinder it was just scraped off. Which really would have been on except it scraped the rings even with the piston so it was just easier to buy a new one then bother fixing that one
somethings not right if its still scarring your cylinder wall? did it make any strange noises before it completly stopped? pinging maybe? figure out whats up before you start it again or you'll be wasting your time?
No it just slowly died. No strange noises or anything out of the ordinary.
when you take the cylinder off check to see if the connecting rod has any sideways play in it. like more than a millimeter or so. move it around its cycle to see if it feels smooth.
Will do.
does it have the oil injection system on it???
Not sure
 
changing the tranny oil would have nothing to do with your cylinder so toss that crap right out the window. secondly, how do you not know if the oil injection is still on??? so you dump oil in the tank under the seat or do you premix it and just dump it in your gas tank?
 
did you do a leak down test? prob have an air leak which leaned it out which melted the exhaust side only of the piston and rings. This happened to me I had all kinds of troble did the leak test, found the leak, been 100% cherry after that. You can tell alot from looking very closely at the piston after it pops.
 
changing the tranny oil would have nothing to do with your cylinder so toss that crap right out the window.
So the only oil that lubricates the cylinder is from the fuel?
secondly, how do you not know if the oil injection is still on??? so you dump oil in the tank under the seat or do you premix it and just dump it in your gas tank?
I don't know alot about engines, didn't know what it was. I premix it 40:1
when you had the cylinder bored and honed did they also chamfer the ports?
I bought it bored so I'm not sure. Its .040 over i believe. The size is 67mm. I honed it myself last time to remove the scars, which weren't deep at all. This time they are even shallower.
did you do a leak down test? prob have an air leak which leaned it out which melted the exhaust side only of the piston and rings. This happened to me I had all kinds of troble did the leak test, found the leak, been 100% cherry after that. You can tell alot from looking very closely at the piston after it pops.
No. Although now that I think about it, the piece that the pipe connects to, that connects it to the cylinder, has a loose nut, never thought it mattered really.

I can get some detailed pics of the piston and cylinder. I'll do it tomorrow morning
 
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