LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start

Description

The LRP Z.21R Spec.4 .21 Pull-Start Nitro Engine is performance-optimised for an unequalled power delivery. This is the perfect entry into the LRP Nitro engine world, and is a great option as a replacement for existing .21 RTR engines. The Z.21R Spec.4 features a special timing for even more power compared to its forerunner, while remaining easy to setup and tune.
Features:

• Perfect upgrade for existing .21 RTR type engines
• Great Value
• XTEC PowerCarb3 15S-2 carburetor – Flow optimized carburetor with 9.0mm insert for maximum power and easy adjustability at the same time
• Universal fit – Fits all major .21 engine mounts
• 3 + 1 Ports
• Standard plug head button – Guarantees easy adjustment of the engine in all conditions
• XTEC T6 engine housing – Especially reinforced heavy duty engine housing for toughest offroad action
• Power Start capable – Prepared for the use of the optional LRP Power Start (not included) for starting the engine at the push of one button

Specifications:
Cubic capacity: .21 (3.49 ccm)
Bore:16.40mm
Stroke:16.40mm
Power:2.15 HP (may vary depending on used fuel, muffler and tuning)
RPM:35,300 RPM (may vary depending on used fuel, muffler and tuning)
Number of ports:3 + 1
Glow Plug:LRP Standard R5 (No. 35051)
Carburetor:XTEC PowerCarb2 15S-2 with 9.0mm venturi
Weight:410g
Class:1/8th Offroad Buggys

This product was added to our catalog on January 27, 2022

Charles Lyons Verified Owner Saturday, Oct 8 2022 (about 2 years ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start I put this engine in a custom built Traxxas Revo 3.3 chassis. And this is one of the strongest engines I have ever owned. It starts every time it holds a tune and it is a screamer. I did break it in properly. but I fail to do maintenance regularly. Even without doing regular maintenance this is the most reliable mill that I have. Not only is it the most reliable but it has unimaginable power and torque and I would recommend it to anyone. I love mine and I will continue to buy LRP products. Oh I forgot to mention that has about three and a half to four gallons on the engine now and I’ve never even had a disassemble disassembl it to do anything to it. It just keeps going and it seems like the more I run it the stronger it gets. 2 customers found this review helpful. James Williams Verified Owner Tuesday, Jan 24 2023 (about 2 years ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start Lrp is a nice motor looks good and has plenty of power for cheap 1 customer found this review helpful. Darrell Badger Verified Owner Thursday, Aug 21 2025 (5 weeks ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start Haven’t started it yet . But what a gorgeous engine. Will update review once I have had the chance to break it in and see what it can do. Dustin Tindal Verified Owner Tuesday, Jul 8 2025 (3 months ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start It’s a ok motor I’ve had it for about a week now and still can’t get it to run right it’s not running too bad but not right either wish I could get some help on this this maybe change it out or help on a new one or something Richard Papini Verified Owner Sunday, Mar 30 2025 (6 months ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start Once tuned right it rips. Installed it in my Losi 8 and very happy with it. Had it for 3 months now and no issues. Isaac Jimenez Verified Owner Wednesday, Jul 20 2022 (about 3 years ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start the engine came and the first time i try it its was hard to pull start till the spring in side collapse ! i took apart and the starter shaft that connects to the crank is seized to the plastic back plate ! it wont rotate unless you apply force thus collapsing the starter spring .i dont blame amain just a freak accident in manufacturing Andries Buskens Tuesday, Jun 6 2023 (about 2 years ago) LRP Z.21R Spec.4 .21 3+1-Port Nitro Engine w/Pull-Start So for $120 you may need to be retarded not to buy this! I own the entire line up! I’m 22 and broke! No regrets! Use O.S plugs! They are as advertised, start with this one and work your way up to the .32!!!! Best life ever 0 of 2 customers found this review helpful. View all reviews