Picked up a blown up blaster and I have some questions

[Fabbed5.0]

well picked up a 2000 blaster from a buddy for dirt cheap. He cracked a piston skirt and luckily it didnt do much damage. miraculously the cylinder walls never got touch, but the crank has a couple wear marks where you can see the aluminum hit it. There are no scratches or gouges just a spot where the aluminum touched the crank. Is it ok to reuse?? It spins free and sounds great, I can see all of the needle bearings thru the slit in the rod and there perfect. So besides that Ill be rebuilding the whole thing. any suggestions will be great.

Jim

 

[twostrokefolks]

well picked up a 2000 blaster from a buddy for dirt cheap. He cracked a piston skirt and luckily it didnt do much damage. miraculously the cylinder walls never got touch, but the crank has a couple wear marks where you can see the aluminum hit it. There are no scratches or gouges just a spot where the aluminum touched the crank. Is it ok to reuse?? It spins free and sounds great, I can see all of the needle bearings thru the slit in the rod and there perfect. So besides that Ill be rebuilding the whole thing. any suggestions will be great.

Jim

if your gonna rebuild the whole thing anyway just replace it

 

[Fabbed5.0]

if your gonna rebuild the whole thing anyway just replace it

Sorry should of added my buddy rebuilt the engine 10 hours ago and it was rebuilt with a wiseco bottom end. So with the crank being this new should I still replace it? Im not the one for cutting corners, So if everyone thinks it needs a new one then ill get it.

 

[KTM RACING 559]

As long as theres no aluminum from the piston skirt down in the crankcase then the crankshaft should be fine.

 

[Blaaster]

If the piston has shed enough skirt to be able to touch the crank, the chances of alum debris in the crankcase is very high, especially if it is a cast piston.

The crank itself may be just fine to continue to run, but if even a single bit of aluminium debris has entered a bearing, all is lost.

The only sure fire way to be safe is to split the cases and clean or replace the bearings.

Do not cut corners, play it safe!

 

[dirtysquared]

x2 On What Blaaster said. Its what you cant see that can hurt you. Id also get the cylinder measured to see if its still in specs also. If it had only 10 hrs on a rebulid, something went wrong, Incorrect jetting, airleak, bad tolerances, not broken in properly.

The good thing is, you can find the answer to about any question you might have on this forum. Good site, good members, and good knowledge from members experiences will definitely help you get it back to good.

Fred

 

[Blaaster]

/\ /\ /\ To have cracked a piston skirt on a fresh build raises warning flags to me.

Pistons usually drop skirts because of a sloppy bore, unless it was grossly mistreated 10 hours is not enough time to produce that much wear.

 

[Fabbed5.0]

If the piston has shed enough skirt to be able to touch the crank, the chances of alum debris in the crankcase is very high, especially if it is a cast piston.

The crank itself may be just fine to continue to run, but if even a single bit of aluminium debris has entered a bearing, all is lost.

The only sure fire way to be safe is to split the cases and clean or replace the bearings.

Do not cut corners, play it safe!

x2 On What Blaaster said. Its what you cant see that can hurt you. Id also get the cylinder measured to see if its still in specs also. If it had only 10 hrs on a rebulid, something went wrong, Incorrect jetting, airleak, bad tolerances, not broken in properly.

The good thing is, you can find the answer to about any question you might have on this forum. Good site, good members, and good knowledge from members experiences will definitely help you get it back to good.

Fred

Yes I have already split the cases and I will be replacing the bearing just to be sade.

/\ /\ /\ To have cracked a piston skirt on a fresh build raises warning flags to me.

Pistons usually drop skirts because of a sloppy bore, unless it was grossly mistreated 10 hours is not enough time to produce that much wear.

OOOOO yes someone didnt know what they were doing it had detonation marks all over the top of the piston. and from looking at the plug it looked lean.

 

[Blaaster]

OOOOO yes someone didnt know what they were doing it had detonation marks all over the top of the piston. and from looking at the plug it looked lean.

Sounds like a case of a leaky motor or incorrect jetting.

 

[Fabbed5.0]

Sounds like a case of a leaky motor or incorrect jetting.

Im gonna say either or, carb was gummed up a little and the two cases had rtv all over it but either way ill be making it right now

 

[Blaaster]

I just know that saying leak test it after the rebuild will be falling on educated ears.

 

[Fabbed5.0]

Yea it will be getting leak tested.

 

[Fabbed5.0]

Anyone sell a complete kit for what I need to do to this motor?

 

[Blaaster]

As I am in Aussie this question is best left for US members.

 

[Pisco-pop]

I found a couple on ebay for around $60 but they look home made so I took mine to my local shop and paid $25 for them to do a leak down test.

 

[dirtysquared]

What type of kit are you looking for? Bottom and top end?

 

[Fabbed5.0]

What type of kit are you looking for? Bottom and top end?

yes (I have to type 15 characters)

 

[Blaaster]

yes (I have to type 15 characters)

Hold down the space bar for a second it will put in enough spaces, finish with a period.

See below example.

 

[Blaaster]

Ok .

 

[Fabbed5.0]

What type of kit are you looking for? Bottom and top end?

Im not sure what type of bottom end but I need at wiseco 66.50mm piston for the toped.

Ok .

Thanks