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Old 05-06-2011, 06:14 AM   #2836
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Hi. I'm sorry to hear about the piston problem. The Kangaroo has a microcast piston, and it is more likely to have a problem like that. I have seen that happen to them. I suspect that the engine was over revved before it was fully warmed up, or run too lean before it was fully broken in. I suggest that you replace the piston, and sleeve with a new one if possible. Usually when the piston gets scratched, the engine will not idle, and loses power.

You will still have more power than a stock Kangaroo with just the modified crank, but the modified piston, sleeve will make it even better for sure.

If you feel that the engine is running fine, you may want to continue to run it. Did the scratch damage the oil rings in the piston?
Hey Uriah,im having the same problem too with my one race old 35+21.what actually happened was i was on the straight and suddenly the engine died! I thought i broke a rod but when i opened the backplate it wasnt the rod.wen i opened up the engine at home,the piston had an inch scratch like fulcrum2 described.i assembled the engine back together and ran it again,the engine kinda lost power and the temperatures were abit unstable.in addition,the compression isnt that good either.but im not gonna give up and try to run it one last time before deciding to rebuild or get a new engine

Last edited by tq23; 05-06-2011 at 06:16 AM. Reason: additional info
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Old 05-06-2011, 07:28 PM   #2837
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Hey Uriah,im having the same problem too with my one race old 35+21.what actually happened was i was on the straight and suddenly the engine died! I thought i broke a rod but when i opened the backplate it wasnt the rod.wen i opened up the engine at home,the piston had an inch scratch like fulcrum2 described.i assembled the engine back together and ran it again,the engine kinda lost power and the temperatures were abit unstable.in addition,the compression isnt that good either.but im not gonna give up and try to run it one last time before deciding to rebuild or get a new engine
How many laps into the run were you? Usually that happens if the engine is over revved when too new, or not properly warmed up.
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Old 05-07-2011, 12:03 AM   #2838
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How many laps into the run were you? Usually that happens if the engine is over revved when too new, or not properly warmed up.
Uriah,
i cant remember how many laps,but i surely do remember it wasnt my first tank on that day.im sure it could be the over-revved issue as my engine is one race old(which the engine ran perfectly) and this was the first time i came back to run my 1/8.
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Old 05-08-2011, 04:43 PM   #2839
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Hi All, could someone advise me what is the crank pin size on a Novarossi 3SCT Tuned.

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Old 05-09-2011, 06:20 AM   #2840
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Hi All, could someone advise me what is the crank pin size on a Novarossi 3SCT Tuned.

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4.26 mm
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Old 05-09-2011, 03:52 PM   #2841
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4.26 mm
Thank You Uriah
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Old 05-13-2011, 11:42 PM   #2842
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Hi, My RB3M piston top has light tan/ brown colouring but so does the exhaust side of the piston, is this an indication of wear, the piston has a vertical mark down the side from the bottom of the lower ring.

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Old 05-15-2011, 09:05 AM   #2843
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Hi, My RB3M piston top has light tan/ brown colouring but so does the exhaust side of the piston, is this an indication of wear, the piston has a vertical mark down the side from the bottom of the lower ring.

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The brown coloring is normal. Especially if you are using a fuel with some castor oil. How is the engine running?
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Old 05-15-2011, 04:49 PM   #2844
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The brown coloring is normal. Especially if you are using a fuel with some castor oil. How is the engine running?
Yep engine running ok did seem to lose a little speed thought the mark on the piston could be the culprit, I will reset clutch and re tune see how it goes.

Thanks Uriah
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Old 05-16-2011, 06:01 AM   #2845
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Yep engine running ok did seem to lose a little speed thought the mark on the piston could be the culprit, I will reset clutch and re tune see how it goes.

Thanks Uriah
The RBM3 Mod is the early one with 3rd Mid range screw, can I fit a Nova 3SCT carbie to the RB without losing performance.
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Old 05-16-2011, 09:06 PM   #2846
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The RBM3 Mod is the early one with 3rd Mid range screw, can I fit a Nova 3SCT carbie to the RB without losing performance.
Yes. Some of the early 3 needle carbs were faulty. The sct carb will fit, and perform fine.
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Old 05-16-2011, 09:39 PM   #2847
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Yes. Some of the early 3 needle carbs were faulty. The sct carb will fit, and perform fine.
Yes I think my carbie is not perfect so will change it, thanks again for the info.

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Old 05-21-2011, 04:30 PM   #2848
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Uriah,

What pipe is best for the 09 or 10 RB M3? I ran a 2652, but now I have a 2660 but have not tried it yet. Let me know your thoughts.

thanks,
Ronnie
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Old 05-22-2011, 10:17 AM   #2849
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Uriah,

What pipe is best for the 09 or 10 RB M3? I ran a 2652, but now I have a 2660 but have not tried it yet. Let me know your thoughts.

thanks,
Ronnie
The 2660 gives slightly better runtime than the 2652, without sacrificing much power. Both are fine pipes for the RBM3. Some of my drivers are also liking the RB2668. I will have more info about the 2668 soon.
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Old 05-22-2011, 10:31 AM   #2850
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The 2660 gives slightly better runtime than the 2652, without sacrificing much power. Both are fine pipes for the RBM3. Some of my drivers are also liking the RB2668. I will have more info about the 2668 soon.
Thank you Uriah. Once you find out about the RB2668, let me know. I also have a t10 rc that I got from a buddy and wanted to know more about what pipe would work for that motor.....I would think the ones we've talked about would be the way to go unless you have another one you would recommend. Let me know your thoughts.

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