R/C Tech Forums - Precirotate D5 Engine

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- - Precirotate D5 Engine (https://www.rctech.net/forum/offroad-nitro-engine-forum/416037-precirotate-d5-engine.html)

We ran this engine on 40% for several gallons without adding a shim. It ran very strong and with a 2035 pipe it was awesome with very good mileage.

My friend has this engine and it is behaving very "on/off", not progressive throttle action. I tried to ask which pipe he was running but he said it was just a Precirotate pipe, which leads me to believe it is a 2088 PR pipe.

If you want more smoothness, more linear throttle curve, less on/off behaviour, would it be a good idea to try a different pipe, or is it a carb-issue?

I was thinking it might behave better with an EFRA 2072 Go pipe?

Quote:

Originally Posted by Eivind E (Post 10412649)

Try to change the clutch springs and tell your friend to calm down his finger ;)

Quote:

Originally Posted by akiyama77 (Post 7925001)

I have the 21C version, and this is just a heads up or FYI of what can happen, my motor has 1/2 gallon on it, and makes great power, and great run time. Last weekend, I noticed some fuel seepage behind the flywheel, no problem I'll put a TKO in. Upon pulling the head off, this is what the piston looked like, and after further tear down the whole piston is like this, crank, sleve and rod show no markings or pitting. I contacted Acend/PR-RC, and went back and forth, I'm concerned about the realiablility now, they indicated that I may have left the motor out in the open and that could have caused it, no, not true. There latest responce is " they see no problem
running in this situation". To say the least I'm not happy with it, the motor still has good compression and pinch, does run for how long who knows. I thought atleast they'd send a repalcement piston and sleeve. What do you think?

I bought a motor and it arrived to me still sealed in the package and the motor was 1 that I ran for a long time. As usual before I break the motor in I disassemble it and oil the bearings and look everything over and make sure everything is tight. When I opened the last of the BRAND motor I ran it looked the same way. I showed it to the importer he said run it and see what happens. TTo this day with 5 gallons on the motor I would not think twice to throw it in my buggy or truggy and run it. I think it was just in the finishing or polishing when it was forged. I would not be concerned and just run it.

Good day guys I am very interested in getting the D5 are they still selling these?

Not sure about in the US, but yes they are still being sold in Asia... I'm running a D5 in my Sworks buggy. its been a strong motor with no issues at all. 4 gallons and counting...

Fletch thanks for the info I think I may pick one up.

Anyone else have experience with the .21BS Evo??

Quote:

Originally Posted by akiyama77 (Post 7925001)

This is just the traces of silicium in the alloy, just normal. Nothing to worry about, any casted pistons with silicium alloy will look like That, all the engines made in Asia (alpha,precirotate, arrow etc) have caste pistons as they are cheaper to produce than cnc made pistons. Plus they contain in the mix of alloy a high percentage of silicium witch is helping with wear.
As the importer told you there is no problems and just run it as it is.
If you wanted a cnc made piston you took the wrong brand and especially paid the wrong price. :)