05 Blaster died

[motox13ds]

I bought a used 05 Blaster for my son recently, he rode it good for 2 weekends then it died. It first stalled when he was slowing down and would not start again. So we cleaned the plug, which it definitely needed replaced. Still it wouldnt fire. So we tried bump starting it and it fired. He rode it for 10 more minutes before the quad stalled out on him again.

So we got a new plug for it, spark looks good but it still wont fire without bump starting it. I am guessing it is a fuel issue. I took the carb apart this past weekend and tried just spraying some carb cleaner around, but it looked decent and didnt seem to help at all. Still will not fire by kicking it.

I am new to 2strokes myself so not sure what I should be looking for. Any help would be appreciated. I still believe it might be in the carb somehow, it is definitely getting plenty of fuel into the carb, but not sure if its coming out. What would i check next? Could reed valves do this? How do I check them and what exactly do they do?

Thanks guys.

 

[toytech]

do a compression test, should be at least 120 to start and run good

 

[Larry's Shee]

What a great father you are !! In cleaning the carb remove the main jet, 6mm hex right in the center, pilot jet right next to it in a recessed hole 1/4 in deep , small straight slot screwdriver needed. Remove float and float needle valve. Now clean it , blow out with air, if you don't have compressor get a can of computer cleaner.
Reeds and low compression also have simular symptoms. Also clean out tank and fuel valve.
Inspection of reed valve entails looking for chips, breaks, and not seating against cage.
Do you still have oil injection? If you do be sure oil tank is full, clean area well before opening.
Two stroke are actually simpler than four strokes, but opperate basically the same.
I would also suggest getting a Clymers repair manual.

 

[motox13ds]

I think I need to get a compression tester and check that. At least that way I can determine if its the top end or a fuel problem in the carb or reeds.

When I took carb apart, I did remove the main jet and spray carb cleaner through all the ports. However I did not remove pilot jet or the float. The float did not appear to be sticking and this was the cleanest carb I've ever seen inside. There was no settiment in bottom of the bowl or anywhere else that I could see.

Yes it does still have the oil injection, debating on removing that from everything I've read and been told. But it does appear to be working still, the plug is wet with a greyish color so oil is definetely getting to the cylinder. I guess I don't know if its enough oil, but it is there.

I did forget to mention that the second time it died on him, after his 10 min of fun when we bump started it, the kick start locked up. My son is 14 and he could not get it to kick, so I jumped on and was literaly able to stand on it without it moving, I weigh 205 lbs. However with a slight kick, it popped and never had that problem again. We have started it once since by bump starting it, everything sounded fine, but it has not been ridin since.

It just seems strange to me that it will start and run great til it just stalls if you bump it, but it will not fire when kicking it.

 

[moppymcjones86]

.... That sounds really messed up like something is not aligned in your engine.

 

[Braaaptor]

I think I need to get a compression tester and check that. At least that way I can determine if its the top end or a fuel problem in the carb or reeds.

When I took carb apart, I did remove the main jet and spray carb cleaner through all the ports. However I did not remove pilot jet or the float. The float did not appear to be sticking and this was the cleanest carb I've ever seen inside. There was no settiment in bottom of the bowl or anywhere else that I could see.

Yes it does still have the oil injection, debating on removing that from everything I've read and been told. But it does appear to be working still, the plug is wet with a greyish color so oil is definetely getting to the cylinder. I guess I don't know if its enough oil, but it is there.

I did forget to mention that the second time it died on him, after his 10 min of fun when we bump started it, the kick start locked up. My son is 14 and he could not get it to kick, so I jumped on and was literaly able to stand on it without it moving, I weigh 205 lbs. However with a slight kick, it popped and never had that problem again. We have started it once since by bump starting it, everything sounded fine, but it has not been ridin since.

It just seems strange to me that it will start and run great til it just stalls if you bump it, but it will not fire when kicking it.

Uh, oh. There's probably nothing wrong with the reeds or carburetor. Sounds to me like the engine seized when your son was riding it.

Do the compression test like everybody has been saying. The engine likely overheated or starved for oil, causing it to lose power and burn up. Your oil injection system may have failed. The grey deposits on the plug are a good indicator that something went boom inside the cylinder. A healthy plug will be cardboard brown in color.

A torched 2-stroke will still run after being burned up, but as you have seen, it must be push or pull started to get it going. It'll never start with the kicker. One of the guys here had a Blasty that would (kinda) run on 30psi compressoin prior to being torn apart for a rebuild.

Check the compression. If you don't have at least 120lbs, time to take the cylinder and head off and have a look inside. Post some pics; we like carnage and can help you figure out what went wrong.

 

[motox13ds]

Ok, been a while but I finally had time to check it. Thanks for all the help guys.

So I did compression test, only 35psi...obviously my problem.

I took the head off it and the piston & rings I am fairly confident are original. The cylinder wall has some scoring and everybody who has looked at it believes boring .020" over will be enough. I measured the bore and it is slightly out of round, measuring between 65.95 & 66.1mm, that is only .006". I am going to order the Wiseco piston kit for the .020" over and my local shop said they would bore it and clean the ports for $75. Oh, and I am also buying the oil injection block off kit, that needs to go!

My question for you all is this....I notice when people are talking about going with a big bore kit everyone says to make sure that who ever does the work also camfers the ports. Is that neccessary when only going .020" over? Should I be asking about this?

One more quickee.....From what I measured on the cylinder bore, that is factory correct? I mean it hasnt already been bored correct? I need to know this so I can make sure to order the correct piston kit.

Again, thanks for all your input guys!

 

[Braaaptor]

A 66mm bore is factory. That cylinder is on its original bore. What kind of damage is present on the piston? It helps to be able to know what happened and why the top end blew...

As far as I know, anytime you bore a cylinder on a 2-stroke to the next oversize, you need to have the ports chamfered. All it takes is one rough spot to catch a piston ring, and boom... I've seen it before. Ugly. And painful, at least in the wallet.

A machine shop which has experience boring 2-stroke engines should chamfer the ports as part of the job. Be sure they know to do so before leaving the jug for work.

When you buy a new piston kit, pay a couple $$ more and get a Wiseco. Run nothing else. Wiseco is the best and most reliable and won't crack or shatter like lesser cast pistons are known to do.

 

[motox13ds]

This piston has some scaring on the side that faces the front of the wheeler. It is worse than the cylinder walls, which I have to assume is normal. From what everyone is telling me, I am assuming the top end blew simply because it was never maintained and most likely still had original piston and rings in it.

While I do know the oil injection was working, I have no way of knowing if it was working properly. It could have been supplying too little oil as well i suppose. Thats not an issue since I am buying the oil injection block off kit, we will mix the gas from now on, much safer. Even before hearing the headaches it could cause, I questioned how well that system would work.

Thanks for the input, I will definitely make sure they are chamfering the ports too. Also, I already planned on the Wiseco, for a few extra bucks why not? Seems stupid to even try another.

 

[motox13ds]

Here is a pic of the cylinder...

If I bore .020" over, do I need to re-jet the carb too?

Any suggestions for a reed valve? Im leaning towards either the Boyesen Super Stock Fiber or Super Stock Carbon?

Thanks.

 

[piezzi]

X2 on being a great dad!

Your "greyish color" sparkplug comment leads me to believe you were either sucking in some extra air from somewhere or the carb wasn't properly jetted.

So I'd do a leakdown test asap to try and determine if there's an air leak.

Good luck!

 

[Braaaptor]

Here is a pic of the cylinder...

If I bore .020" over, do I need to re-jet the carb too?

Any suggestions for a reed valve? Im leaning towards either the Boyesen Super Stock Fiber or Super Stock Carbon?

Thanks.

Looks like a lack of lube failure from the pic of your cylinder. The intake side has some scoring, which suggests the engine did not recieve sufficient oil and finally quit.

You shouldn't need to re-jet when simply boring out .020" oversize, but it is a good idea to check your jetting by doing a plug chop once you get the engine back up and running.

Boyesen carbon fiber reeds are a good upgrade over stock, but if I were you, I'd snag a VF3 reed cage off ebay and run that. You will notice a nice improvement in throttle response and performance over stock with a whole V-Force 3 reed cage...

 

[Larry's Shee]

One thing that hasn't been dicussed is how old is your son? How much experience does he have? While a lot of these suggestions are all good, is he ready fo a "Hot Rod"? I:I I would suggest a set of dual stage reeds as they are a maintenance item.

 

[93blasterlover]

Go with boyson they add great throttle response

 

[motox13ds]

My son will be 15 this August. He does not have a lot experience on trails or things of that sort, but he has been riding fields for a couple years now when he gets a chance to find a loner wheeler. He has even rode a 450r (not allowed to open it up, lol) and knows how to handle the power. It only goes as fast as you tell it to.

I ordered my parts last night for him....

Wiseco .020" over piston kit
Wiseco wristpin bearing
Tusk top end gasket kit
Boyesen Super Stock Fiber Reeds
Oil Injection Block Off kit

Grand total = $185 + $75 for the bore, hone, & chamfer.

Thanks for all your help guys.

 

[Larry's Shee]

Make sure you use NEW wrist pin cir-clips