.21 & .28 Nitro engine rebuilding

Normally I just run a engine for a season and then replace it. Depending on what a engine needs and how much the parts are will determine if it's worth rebuilding. In this case a friend of mine had a nice O.S. that had bad bearings and bad o-rings in the carburetor. The piston and sleeve were both good. Parts were only about $70 USD. This engine was definitely worth rebuilding.
エンジンの修理
レースへの参加エンジン準備編
www.oakesmfg.com

[@nikolaypetrov4711]

Why not use isopropyl alcohol (iso-propanol)? It's still safe for your seals and is not highly toxic, unlike pulverized methanol.

[@oakes4501]

I am not a expert on seal compatibility with different solvents. O.S. and SH don't publish exactly what kind of material the seals in their engines are made out of. I know the seals in the engine are tested to work with methanol. I can't endorse or disregard the compatibility of the seals with isopropyl. I do know that if you use methanol you won't have any seal compatibility issues. I think that if a individual is careful, utilizes proper PPE and minimizes their exposure to methanol they should be perfectly safe. It's not like a industrial situation where you are exposing your self to said chemical all day every day. When rebuilding a hobby engines your exposure to said chemicals is minimized when compared to some one that does auto repair for a living.

[@tavvs4102]

great information video

[@oakes4501]

Thanks

[@thetoddperspective]

Hey, that SH engine in the beginning of the video, what did you think of it?

[@oakes4501]

The PT2017 is a decent engine, but when I used it with the SH 2060 pipe I didn't really like the powerband. With the 2060 pipe it hits really hard at about 1/3 throttle. This can be good and bad. If you have good traction and you have jumps that you don't have much room to get up speed the PT2017 and 2060 pipe is fantastic. How ever if traction conditions are low the PT2017 with the 2060 pipe can be difficult to drive. The 2060 pipe also seems to fall flat on the top end. So it can be doggy on top if you run on really large tracks. If you are going to run a PT2017 I would recommend running the 2075 pipe. I have a PT21A0-XBG, but due to covid I have not had a chance to test it. I also have a PT2018-P3XBG and have not had a chance to test it either. I do know that the PT2018-P3XBG does have a lot of changes made to it from the PT2017 to make it more drivable. Honestly my recommendations would be to go with a PT21A0-XBG or a PT2018-XBG PRO with a 2075 pipe. If you really want to run the PT2017 definitely go with the 2075 pipe. In general I don't really recommend running the 2060 pipe. To much bottom and not enough on top.

[@lance4906]

What does TDC mean?

[@oakes4501]

It means top dead center. The piston is at it's highest point.