blew it's stack

Racer51

New Member
May 19, 2011
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Northwest Ohio
Hey guys I got my blaster back today and figured out what was wrong with it. Just look at the pictures, keep in mind I dident ride it enough to do any of this damage. I've only had it start up once and for 10 minites, since i got it in september. Also the stuff circled in yellow and red are the problems obviously. Thanks for looking and helping me with advice in advance.
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1O minutes with an air leak, wrong octane fuel, or incorrect jetting will do this kind of damage.

Looks like you need a lesson on jetting.

Have you changed your pre mix ratio.

Could be also caused by lack of lubrication as it has taken out the inlet side as well.

Just read your services ad in your sig.. "As well as full carb cleaning/rejetting if necessary for anything specific, prices starting at $20."

So I guess a jetting failure is out of the equasion!
 
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The previous owner of the previous owner had let the quad sit for 3 yearsand left untuched then the second owner had the cases split to remove a magnetic drain plug stuck on 1 of the transmission gears and put back together by the same guy who took it apart. The jetting it was at when it was run for 10 min. was at 230 main and 32.5 pilot I believe that's stock like 95% shure. Anywho I called ken up like 2 days later and he told me to re-jet and clean it and to put a 260 main and leave the pilot alone. So I did and my mechanic I just had it at said it was spot on perfect. Also my brand new VF3 reeds were in excelent shape not that they were used what so ever. My pre mix ratio is 32:1 with Amsoil Dominator/93 Premium gas. Thats all I can think of for now.
 
No I dont have a leak down tester and It shut down afterwards anyway. I know slick sells them for $30 shiped and I might just get one if I got any money left. No the reeds are literally brand new, what I really need to learn what happened is how I can have a piston ring break a 1 inch chunk off.
My mods before were 230 main jet FMF pipes on a stock carb, motor bored .40 over
Now I'm gonna probably have to bore 1 size over to get those gouges out of the exhaust port. 260 main VF3reeds on stock carb.
And probably leave everything else alone if I can help it. I'm kinda teater tottering on getting it quoted for porting but that's a far off fantasy cause I got hit hard on hours and money is gonna be pretty tight for a good while so IDK. Lets just asume no vito's stroker or porting for now OK.
 
IMHO #260 main with a FMF is just about lean enough to cause the problem.

The problem was started by the #230 main and the #260 finished it off.

A little lean = runs like a scalded cat, overheats piston crown, = $$$$$$$.

Changing reeds without doing a leak down test. Hold your hand out you naughty boy, it deserves a good smacking.

With your vast experience which you have been trying to pass on, I would have expected greater things of you!

Bit of reading you might like to do would be on plug chops, so that you dont get caught with a too small main jet again.
 
IMHO i'm not familiar with that shorthand.

"With your vast experience which you have been trying to pass on, I would have expected greater things of you." I know that now cause it's gonna cost me between 150-200 to get a top end kit and haveing it bored...and I havent even checked the rod yet. So there's another $225 dollar part gaskets and all if it needs changed out.
The 260 main was added after it quit and never started up with it in it.

Why what would you have it at a 290??? The needle is at second from the top now from the middle I forgot to mention that sorry. But not to worry will do on the reading the plug chop how to's and I'll be writing notes in stages so it's easy to follow ok.
I dont wanna sound like a broken record or something but lean jetting wouldent break off a good chunk of ring would it? Wouldent it just burn up the piston crown and take material out of the ring and cylinder??
 
Another senario just entered the equasion, the needle on the second from top clip would have been another contributor for a lean mix.

Lean mixture will cause overheating of the piston crown. Heating causes expansion of ring lands, and rings, prohibiting a ring from settling back into the grooves.

What has prolly broken that ring, is that maybe the expanded ring has siezed in the bore, broken a land, and then with nothing to support the ring it has snapped.

You worry me bro, you offer a jetting service, but you need to read up on plug chops!
 
Thought I'd throw this info out here, too, to clarify factory recommended jetting. It is true that FMF recommends running a 260 main jet with their pipe, but remember, this recommendation is based upon the fact that your Blaster is still being run with the oil injection system.

When you remove the injection and go to pre-mix, you have to re-jet right there because now you have gasoline AND oil passing through the main jet in the carb. If you keep the stock main, it will run lean because you can't get enough oil and fuel through the jet for the engine's needs. SO, figure on bumping the recommended jetting for a pipe up AT LEAST 1-2 sizes if you're not running oil injection. So, depending on elevation, you'll need somewhere between a 280 and 290 main with that pipe. Same goes for Toomey pipes. The factory recommends a 310 main. Run a 320 or 330 with no oil injection.
 
IMHO= In My Honest Opinion

Two strokes don't get a chance to "rest" and cool down between power strokes, like a four poke does. 8-|

IMHO, unless you are fouling plugs or blubbering like a drunken idiot, you are not to rich.

As you go from rich to "perfect" jetting, power rises quickly and ex temps moderately. As you go from "perfect" to lean, power drops very slightly but ex temps rise VERY quickly. :eek:

A dragger can get away with leaner jetting and more timing cause they only run for a few seconds. If you want to run for hours straight, you have to be more consevative. The only thing that cools the piston is the incoming charge under the piston and as it washes acrossed it on chamber filling. Remember the piston has .003-.004 clearance (cold) so it's only touching the cylinder basicly at one point.
 
Thought I'd throw this info out here, too, to clarify factory recommended jetting. It is true that FMF recommends running a 260 main jet with their pipe, but remember, this recommendation is based upon the fact that your Blaster is still being run with the oil injection system.

When you remove the injection and go to pre-mix, you have to re-jet right there because now you have gasoline AND oil passing through the main jet in the carb. If you keep the stock main, it will run lean because you can't get enough oil and fuel through the jet for the engine's needs. SO, figure on bumping the recommended jetting for a pipe up AT LEAST 1-2 sizes if you're not running oil injection. So, depending on elevation, you'll need somewhere between a 280 and 290 main with that pipe. Same goes for Toomey pipes. The factory recommends a 310 main. Run a 320 or 330 with no oil injection.
Ok so should leave it and plug chop or would swaping it out for a 290 be a better starting point?
My mods are a .50 over piston from a .40 right now cause I havent got it bore/honed yet. No porting a stock carb Jetting what ever it needs to be at??? 260 is in it a 32.5 pilot FMF fatty with a turbinecore 2 and VF3 reeds with no lid. my elevation is 600 ft and thats it.
IMHO= In My Honest Opinion

Two strokes don't get a chance to "rest" and cool down between power strokes, like a four poke does. 8-|

IMHO, unless you are fouling plugs or blubbering like a drunken idiot, you are not to rich.

As you go from rich to "perfect" jetting, power rises quickly and ex temps moderately. As you go from "perfect" to lean, power drops very slightly but ex temps rise VERY quickly. :eek:

A dragger can get away with leaner jetting and more timing cause they only run for a few seconds. If you want to run for hours straight, you have to be more consevative. The only thing that cools the piston is the incoming charge under the piston and as it washes acrossed it on chamber filling. Remember the piston has .003-.004 clearance (cold) so it's only touching the cylinder basicly at one point.
Ok good to know
Like moving the needle will help a starting issue 8-|:D:eek:

No I thought moving the needle, It would compensate the Vforce 3reeds cause they tend to make the bike run rich and moving the needle up makes it run leaner so the 2 adjustments would even out. Am i right to assume this?
I know moving the needle position wont fix a starting issue 8-| But i dont know if it's blubering like an idiot or not, I dont have it fixed yet to know. I Haven't had it running long enough to know eather.........
 
No I dont have a leak down tester and It shut down afterwards anyway. I know slick sells them for $30 shiped and I might just get one if I got any money left. No the reeds are literally brand new, what I really need to learn what happened is how I can have a piston ring break a 1 inch chunk off.
My mods before were 230 main jet FMF pipes on a stock carb, motor bored .40 over
Now I'm gonna probably have to bore 1 size over to get those gouges out of the exhaust port. 260 main VF3reeds on stock carb.
And probably leave everything else alone if I can help it. I'm kinda teater tottering on getting it quoted for porting but that's a far off fantasy cause I got hit hard on hours and money is gonna be pretty tight for a good while so IDK. Lets just asume no vito's stroker or porting for now OK.


$30 for an airleak tester is a GOOD deal as Slick is basically giving us his time to build those. An airleak tester is a tool that every 2 stroke rider should have laying in the drawer even if they're not even a mechanic.

However, that doesn't look like your issue. There seem to be a few problems here: First off, was your airbox lid still on the engine when you put the 260 mainjet in there? If so, you might have been somewhere close. If not, a 260 main could still have been dangerously lean. An FMF fatty pipe and no airbox lid needs a 290 or a 300 at anything under ~3,000 ft of elevation and a 280-290 up to ~5,000 ft.

Second, the 1" piece that broke off is what's called the "ring land". It's the aluminum between the two rings that helps support the ring to keep it from fluttering and directs the gas flow to keep the rings sealed against the cylinder wall. Ring lands don't just "break", they get broken. Mainly by the ring snagging like yours did! The piston has a big gouge down it where the piston ring locating pin fell out (it looks like in my professional opinion) and the ring was allowed to rotate. The end of the ring can pop out into the port and snag it moving by and BAM, it frags that piston. This could have been a total freak accident (very possible) or it could have been from previous damage from the PO mishandling the piston OR it could have been cylinder taper allowing the ring to slam into the locator pin.
 
$30 for an airleak tester is a GOOD deal as Slick is basically giving us his time to build those. An airleak tester is a tool that every 2 stroke rider should have laying in the drawer even if they're not even a mechanic.

However, that doesn't look like your issue. There seem to be a few problems here: First off, was your airbox lid still on the engine when you put the 260 mainjet in there? If so, you might have been somewhere close. If not, a 260 main could still have been dangerously lean. An FMF fatty pipe and no airbox lid needs a 290 or a 300 at anything under ~3,000 ft of elevation and a 280-290 up to ~5,000 ft.

Second, the 1" piece that broke off is what's called the "ring land". It's the aluminum between the two rings that helps support the ring to keep it from fluttering and directs the gas flow to keep the rings sealed against the cylinder wall. Ring lands don't just "break", they get broken. Mainly by the ring snagging like yours did! The piston has a big gouge down it where the piston ring locating pin fell out (it looks like in my professional opinion) and the ring was allowed to rotate. The end of the ring can pop out into the port and snag it moving by and BAM, it frags that piston. This could have been a total freak accident (very possible) or it could have been from previous damage from the PO mishandling the piston OR it could have been cylinder taper allowing the ring to slam into the locator pin.

Thank you sir. I'm planning getting ahold of slick later tonight and seeing if he's got any on hand (he probably does) :)
2) yes the lid was on but I figured I'd squease a little bit more out of it with the lid off. Not that it was run with the lid off while the 260 was in there at the time. So I amgonna find a 290 and put her in come monday.
# Ok the ring land thanks for teaching me that term along with locating pin But to clarify the ring gaps have to be at opposite ends of the center line/piston pin? Also both locating pins are gone there are not in the piston...........................Would a very very very slight wiggle in the crankshaft rod cause this kind of damage over time???
 
Wiggle in the conrod has nothing to do with why the rings broke.

You stated that it was running a #230 main jet with a FMF pipe, correct me if I am wrong, thats what caused the carnage.