Question: I think the bearings in my engine are worn out or damaged? Are they worth replacing?

Answer: Yes and No. Sounds like we are waffling around on this one doesn't it? Well it comes down to HOW you replace them.

Consider this:

1) KNOWLEDGE and TOOLS. To actually replace the bearings in your existing crankcase you have to take them out. We recommend replacing front and rear bearings at the same time because it would be unusual to find one worn out and the other in good shape. To get them out you have to know what you are doing and most importantly to put new bearings in you have to be careful not to damage them during installation. Removing and installing bearings requires some knowledge and a few small special tools to do the job right. In our experience most modelers have some difficulty with this and often damage the new bearings.

2) WORK/EFFORT/TIME. Do you have the time? It takes about 30-60 minutes to do a good job IF you have the tools and knowledge to change bearings effectively.

3) COSTS. The cost of two bearings can vary widely from engine to engine and source to source. The price for a front/rear set of bearings for the VMAX 46PRO and 52PRO is about $20 as of 20050228. This may have increased since then. You may be able to run around town and find them cheaper at a bearing house if you can get the size you need but with gas and automobile depreciation the way it is today you can't drive far even to get bearings for free!

Question: So what to do when you have neither the knowledge, the tools, the time or money to burn? Is there another way short of dumping the engine?

Answer: Yes there is! Swap out the crankcase complete with bearings. Once you've got the engine taken apart to the point where you can actually remove the bearings you are way ahead of the game if you just replace the entire crankcase and bearing set with brand new components. As of 20050228, the price for the crankcase with bearings already installed for the VMAX 46PRO and 52PRO was just $5 more than  the cost of the bearings by themselves. So for a few bucks more you can do less work, have a much better chance of a satisfactory outcome and get the job done quickly so you can get back to flying!

Conclusion: On a VMAX engine we recommend changing the crankcase and bearings for a few dollars more than just changing the bearings themselves.