Requesting 60-size Engine Recommendation

[PaulH]

I have a Bergen Intrepid 60 that I am in the process of tearing down and rebuilding. I haven't had a chance to look at the engine yet to see what condition it's in, but it does have a Hatori muffler attached.

If I do end up replacing the engine, what would be the best choice for this bird? OS 61? OS 70? YS 61? I have everything necessary to convert this bird to a 90, but as I am still early in the learning process, lower fuel consumption is a higher priority to me than raw power.

Any input is welcome. Thanks!

[WillJames]

I am definitely no engine expert, I have owned and flown all the below and I will take a stab at your question.

OS 61 WC - Reliable motor, good power NIB on the used market is dirt cheap pricing. You can probably use your existing Hatori. Uses muffler pressure back to tank.

YS-61 - Good running motor good power. More maintenance than the OS (IMHO) but no muffler pressure needed so your clunk line and other lines last a lot longer. Easy to tune has 3 needle carb like the OS 61. Might be able to use your existing Hatori Muffler.

OS 70 - More power, but some people have issues with them failing early and some seem to run a lot better than others. You will need new muffler to get optimum power out of it. Lots less fuel consumption than the 91.

[Laurens]

OS70 seems to break because people set them too lean is what I heard.

[bono1]

Buy the os 61 wc. They are (as Baja170 mentioned) really inexpensive now that the 90's are hot. The 61 is easy to start and easy on fuel compared to a 90. I have three of these and have had no problems. I also have an os 70, but it has a lot less time on it than the 61's but seems to be a more powerful engine which burns more fuel than the 61's. So, I guess what I am saying is go for the 61 and burn more fuel. Good luck!
Sam