how can u tell if u need a new nitro engine

[seanl]

what can u do or look for to find out if u need a new nitro engine or new parts ie piston ect

thanks seanl

 

[x_doug_x]

what can u do or look for to find out if u need a new nitro engine or new parts ie piston ect

thanks seanl

you rarely ever need a new engine, just piston/sleeve, and they usually come with rod i think.

 

[seanl]

so if i was to take mine out what would i be lookin for on the piston an sleeve to see if i need a new one ?

 

[LosiLST]

Honestly in cheaper engines it's better to just buy a new one all together. The barrings will wear out and crank shaft will too. When your already spending over half the price of the engine just buy a new one.

But if you were looking at the piston and sleeve out of the crankcase then you would look for blackening on the piston, scratches on the sides of the sleeve, piston, the piston would be able to go either all the way through the sleeve or partially out of the top. And would look icky.

 

[LBSinGTX]

Try turning your flywheel. If there isn't much or any resistance at TDC, your pinch/compression is probably gone.

 

[brad55102]

This is a piece by OLDS97---- Talking about rayaracing.com
It should help
enjoy
I've had 4 P/S's done by him and all of them were done well. Also, none of the con-rods in those engines exhibited any slop, so I didn't feel the need to replace them. Since I had him do a mild pinch, that also helps with the re-break-in stress and strain on the con-rod.

I look at quite a few different factors when deciding this.

If the following is true, I get a pinch:
1) main bearings are good with no slop
2) con-rod is good with no slop
3) piston skirt is good with no chips/dings/damage
4) piston top is good without severe pitting, cracks or any damage
5) sleeve is good without scratches
6) crank shaft is still clean and smooth without scratches where you can see it under the carb neck
7) OWB is still good
8) crank case has no cracks
9) carb exhibits little/no wear on the slide mechanism

If 1, 2 or 5 are bad, I determine how expensive to replace, then consider pinch.

If 2, 6 or 7 are bad, I still may pinch to eek out a few more gallons.

If 3, 4, 5, 6, 7 or 8 are bad, I consider the engine a parts engine and buy a new one.

If more than one of 1, 2, 5, 6 or 7 are bad, I consider it a parts engine and buy a new one.

For $200 engines on down, this is how I determine the "worth" of repairing an engine. Once you buy a few of these parts, your money ahead just to buy a new engine and keep the old one for spares.
__________________

 

[x_doug_x]

This is a piece by OLDS97---- Talking about rayaracing.com
It should help
enjoy
I've had 4 P/S's done by him and all of them were done well. Also, none of the con-rods in those engines exhibited any slop, so I didn't feel the need to replace them. Since I had him do a mild pinch, that also helps with the re-break-in stress and strain on the con-rod.

I look at quite a few different factors when deciding this.

If the following is true, I get a pinch:
1) main bearings are good with no slop
2) con-rod is good with no slop
3) piston skirt is good with no chips/dings/damage
4) piston top is good without severe pitting, cracks or any damage
5) sleeve is good without scratches
6) crank shaft is still clean and smooth without scratches where you can see it under the carb neck
7) OWB is still good
8) crank case has no cracks
9) carb exhibits little/no wear on the slide mechanism

If 1, 2 or 5 are bad, I determine how expensive to replace, then consider pinch.

If 2, 6 or 7 are bad, I still may pinch to eek out a few more gallons.

If 3, 4, 5, 6, 7 or 8 are bad, I consider the engine a parts engine and buy a new one.

If more than one of 1, 2, 5, 6 or 7 are bad, I consider it a parts engine and buy a new one.

For $200 engines on down, this is how I determine the "worth" of repairing an engine. Once you buy a few of these parts, your money ahead just to buy a new engine and keep the old one for spares.
__________________

well if you rebuild a engine with bad piston/sleeve yourself the traxxas .15 pistons and sleevs were 32 bucks plus tax, and the gaskets you'll need 2, a head gasket and a cover for the plate on the side those are prob. 5 bucks, so for about 40 bucks with tax u can rebuild a motor, how much is a new one?

 

[neobart]

If the engine seems to lose bottom end snap and has a hard time idling, then it's about time to rebuilt/replace.

 

[Metalhead Matt]

Don't forget about Traxxas's engine replacement plan. 3.3 shipped for $80. Hard to beat that.

 

[stevecz28]

the 2.5 is 80 shipped....3.3 is 115 shipped

 

[seanl]

the piston is a little brown on top is that normal ?