2003 Yamaha Blaster Seize?

[JohnstonOctober]

Okay, I just got my blaster about 3 days ago, I was riding it fine for the first 2 days, but today i got out and started riding. I noticed that once i would get to the top of 4th it would bog, so i kept it easy. I just wanted to get some ride time in before i had to head home. So i was about 2 football fields from my house when it started to die so i gave it gas and it just sounded like it was bogging, geared down gave it a little more thinking it was a fouling plug, made it back it just died. Tried to kick it back up so i could put it in the garage, kicker was stiff. i started messing around and I bumped it backwards in gear and it freed up. NO COMPRESSION, i already knew it was gone of course when the kicker wouldnt push down, so i rolled it onto the trailer took it to my shop and started a tear down. Piston was scored and scratch all around so what the cylinder, even the crank bearings were full of metal. I am trying to make sure before i start rebuilding it, was it the oil pump or was it cause it was just worn down and the piston was getting loose enough to catch the exhaust port. the piston looks like it got it more on the exhaust side, but the whole thing got it pretty good. I am gonna buy a 240cc big bore kit and redo the crank bearings, but I dont want to just throw 500 into it and have it lock up again.

I also need recomendations on the 240cc big bore, cheap as possible not much money to spend, also reliable crank bearings.

This is my first quad, I always had yz's , i loved it till this

 

[89blaster89]

the question is do you want it really fast or do you just want a cheap topend rebuild. is the pump working? well either way get rid of it and you wont have to worry about it. if the crank is full of metal than so is your gearbox im guessing, i would split the cases. get some pictures up of the carnage

 

[Larry's Shee]

the question is do you want it really fast or do you just want a cheap topend rebuild. is the pump working? well either way get rid of it and you wont have to worry about it. if the crank is full of metal than so is your gearbox im guessing, i would split the cases. get some pictures up of the carnage

Gear box (transmission) and crank area are totally seperate, Unless you blow a hole in the cases. Crank might be iffy if you got metal into big end brg.

The thing now is to figure out WHY it crapped the bed.
Pics of the piston might help. It's to late now, but a leakdown test would have been helpful to diagnose why. Highly doubt the oil pump failed, search a little and you'll see. Operator error is usually the cause. Did you happen to flip on your ride? Was oil lines still hooked up? Regardless, what does top of piston look like? Spark plug? Did piston break or is it still mostly one piece?
Another helpful thing would be to list ALL modifications (mods) air filter setup, pipe, etc. and jetting in carb.

BTW
WELCOME
to the

DIRT PILE ! ! !
I:I I:I I:I​

 

[JohnstonOctober]

The piston is still all in one piece just a very light chip near the exhaust and gawled up place and scratches all around. It doesn't have any mods it's all stock, I didn't wreck it or anything was riding just like the day before, all the oil lines were unhooked, I just took the oil tank off and and cleaned the hoses out and made sure the tank wasn't clogged it all flows. If the oil pump stopped working would it have completely seized up or would it happen like this the piston was free when I took it apart.

 

[JohnstonOctober]

I think this had to do with it, the day it happened I rode it enough to warm it up and it started knocking, I didn't think anything of it but I parked, was off about 5 minutes and I got on I had stopped, but started again once it warmed bac up then all the bad happened on the way back.

 

[89blaster89]

Gear box (transmission) and crank area are totally seperate, Unless you blow a hole in the cases. Crank might be iffy if you got metal into big end brg.

The thing now is to figure out WHY it crapped the bed.
Pics of the piston might help. It's to late now, but a leakdown test would have been helpful to diagnose why. Highly doubt the oil pump failed, search a little and you'll see. Operator error is usually the cause. Did you happen to flip on your ride? Was oil lines still hooked up? Regardless, what does top of piston look like? Spark plug? Did piston break or is it still mostly one piece?
Another helpful thing would be to list ALL modifications (mods) air filter setup, pipe, etc. and jetting in carb.

BTW
WELCOME
to the

DIRT PILE ! ! !
I:I I:I I:I​

i thought i heard him say the piston broke? my bad, well either way you should split the cases to get the crap outta there

 

[itstyler]

If your replacing crank bearings that will remove one potential problem. If i was you i would go ahead and removed that oil pump and premix your gas. Even if that was not the problem this time it may cause you some problems in the future.

You should also check all your carb settings and jet sizes and give it a good cleaning before you start that rebuilt motor up.

Good Luck!! I:I

 

[joeak47]

all the oil lines were unhooked, I just took the oil tank off and and cleaned the hoses out and made sure the tank wasn't clogged it all flows.

BUT...
Did you "BLEED"
The system?
My "guess",and I'm very,very sure, is that the oil injection system was NOT bled after it was disassembled and then re-assembled. Its a good thing to clean the system,but it must be bled. After filling the oil tank,disconnect the oil line (the big one) at the pump and let it run into a cup until oil comes out solid oil with no air. ...Now plug it back in to the nipple on the pump.

NOW...
remove the bleed screw on the oil pump and let the oil flowout of this hole until it comes out solid oil with no air bubbles. When its solid oil,put the bleed screw back in.

NOW...Remove the line that goes from the oil pump to the carb (the little line) and fill it full of oil with a syringe and push it onto the nipple of the oil pump,and then install the other end onto the nipple of the carb. your done assuming that all the components are in good shape and not damaged (leaks)! Also don't forget the tiny wire hose claps that lock the lines on the oil pump,and the metal cuff that locks the line on the carb, You can run without these,but to do it right,use them. Thats why they're there.
As added insurance,you can also squirt a small amount of oil in the throat of the carb befor start up.

Its very doubtful that the "Oil injection system" failed. VERY unlikely! Its usually due to the operator not filling the oil tank,or putting oil in the tank until AFTER it has run dry. I don't understand it... You can see the oil tank from over 300 yards away and see if there oil in it.
I also suggest that you purchase a service manual for your blaster and read it. There's a wealth of info in them.

 

[jus_me]

BUT...
Did you "BLEED"
The system?
My "guess",and I'm very,very sure, is that the oil injection system was NOT bled after it was disassembled and then re-assembled. Its a good thing to clean the system,but it must be bled. After filling the oil tank,disconnect the oil line (the big one) at the pump and let it run into a cup until oil comes out solid oil with no air. ...Now plug it back in to the nipple on the pump.

NOW...
remove the bleed screw on the oil pump and let the oil flowout of this hole until it comes out solid oil with no air bubbles. When its solid oil,put the bleed screw back in.

NOW...Remove the line that goes from the oil pump to the carb (the little line) and fill it full of oil with a syringe and push it onto the nipple of the oil pump,and then install the other end onto the nipple of the carb. your done assuming that all the components are in good shape and not damaged (leaks)! Also don't forget the tiny wire hose claps that lock the lines on the oil pump,and the metal cuff that locks the line on the carb, You can run without these,but to do it right,use them. Thats why they're there.
As added insurance,you can also squirt a small amount of oil in the throat of the carb befor start up.

Its very doubtful that the "Oil injection system" failed. VERY unlikely! Its usually due to the operator not filling the oil tank,or putting oil in the tank until AFTER it has run dry. I don't understand it... You can see the oil tank from over 300 yards away and see if there oil in it.
I also suggest that you purchase a service manual for your blaster and read it. There's a wealth of info in them.

Thanks for the info on that. I was just wondering how that went about?? I need to do this myself since i just took my oil tank off of the one blaster and heard about bleeding it and want to sit how it went.but ultimately I'm doing oil block of kit.. just havn't had time yet..thanks.

 

[joeak47]

Thanks for the info on that. I was just wondering how that went about?? I need to do this myself since i just took my oil tank off of the one blaster and heard about bleeding it and want to sit how it went.but ultimately I'm doing oil block of kit.. just havn't had time yet..thanks.

Glad it helped you out.

However,I'm sticking with my "oil injection"! I love it and it runs just fine with all my mods,such as porting,head re-chamber,matched transferes,etc.

 

[JohnstonOctober]

Well I am buying a block plate and premixing, after this. I the blaster was exactly how I got it was full of oil and gas so I just rode.

I am just gonna rebuild ad do that, I need to know if my crank is bad now, the bearings are shot, but the rod bearings are fine as far as I can see the roll with no noise but the rod has about a 1/16th of play in it, if I remember is it not supposed to have any, I can do a complet engine rebuild for around 350 just need to know if I need to replace my cranks now.

 

[itstyler]

Well I am buying a block plate and premixing, after this. I the blaster was exactly how I got it was full of oil and gas so I just rode.

I am just gonna rebuild ad do that, I need to know if my crank is bad now, the bearings are shot, but the rod bearings are fine as far as I can see the roll with no noise but the rod has about a 1/16th of play in it, if I remember is it not supposed to have any, I can do a complet engine rebuild for around 350 just need to know if I need to replace my cranks now.

If your crank rod has vertical play it needs rebuilt thats the quickest rule of thumb but you just have to look it over good make sure that bearing moves perfectly.

I got a new in box wiseco crank for $120 shipped if you need one.

If your quad is very well maintained and you know how that oil injection system works its ok to use but for the everyday rider its best to mix the gas so your 100% sure its getting the oil.

 

[JohnstonOctober]

It has no vertical plays just that 1/16th inch of horizontal play. It was squeaking after the incident but a dot of oil and its quite again.

 

[Blaaster]

It has no vertical plays just that 1/16th inch of horizontal play. It was squeaking after the incident but a dot of oil and its quite again.

Squeaking is a bad sign that that bearing has suffered trauma, even run dry.

Even though it may seem fine now you have oiled it, just what was causing it to squeak could remain a mystery until it fails at 8,500 revs.

I would get that end looked at by a professional.

 

[JohnstonOctober]

Yea thanks, I am gonna get a wiesco bottom end kit and a wiesco top end kit and send my cylinder to powersealusa for a over bore, gonna cost me around 320-350 but at least I will know that it's good then, I hate buying people's hand me downs.

How would I go about taking loose the nut that's holding the clutch basket on, I forgot how I did it on my yz?

 

[Blaaster]

You need to get or make a basket holding tool.

 

[joeak47]

oil injection system works its ok to use but for the everyday rider its best to mix the gas so your 100% sure its getting the oil.

Disagree... I ride mine hard and everywhere,and almost everyday as soon as it warms up. Totally reliable! I'm 100% sure its getting oil. I:I No worries here.

 

[JohnstonOctober]

Thanks, I decided to do a full restoration on the whole blaster. I have split the case, and waiting on some money to come in to order the kits for the bottom end.

 

[lofosho97]

X2 on the premix.

 

[Blaaster]

Only remove the oil pump if you intend running an oil that does not suit injection.

Another reason why oil injection is removed is so that carbs that support it can be used.

I choose to run premix because my application suits it, I vary my oil ratio the simulate jetting changes, I cannot do that with injection.

Keep the injection unless you have good reason to premix.