I have been offered a deal on a BME 105 and I am curious about peoples experience with the engine.

I have read on here about prop slippage issues even with the two "pins" on the hub, and possible problems getting headers for it.

What should I take into consideration about this engine when contemplating whether or not to buy it?


Thanks in advance all!

Price

I had a 102 Evo and just sold it due to noise considerations at our field (I'm going 50cc with a can to prolong the inevitable).

I loved the motor! If you use a Tru Turn (nice, heavy knurling on the backplate) you will be fine. Drill the backplate for the two bolts on the hub and you will have no slip.

Used 102's are going for $700 - $800 or so. If the price is right you won't be sorry. Mine turned a Menz 26x10 at 6250 rpm. Easy starting, great transition.

Note: I have some props, a 4 1/4" Tru Turn Ultimate spinner, and a 7/16" pilot bit for drilling props that I plan to put on sale here soon. PM if interested.

Chuck

The 105 is essentially the same as the 102. Good, reliable light engines with lots of power. Parts are not a problem, just call Keith.

Baffles are the key to power and longevity. If it has little compression it was run hot. That's the mistake so many have made with a BME twin. No baffles equals poor cooling. Baffles are easy to do, all you have to do is think "funnel". Think of the engine as the small end of the funnel, with the opening in front of the engine as the large end. It's only the concept of directing the air through the engine, then out, and not over or around it that matters. Anything that does that works. Then again, that should be done with any twin or fully enclosed single. So many kill their engines through a lack of understanding.

If the price and compression was right I'd buy it in a minute. Headers and cans are stuff I'd worry about later. The only hard part about a can is the header and flange, and those can be made at any machine shop.

I don't have to worry about abuse, this one is NIB.

One part of the dilemma is that I have some store credit built up at my LHS, with that I can get a DA-100 for the same cash out of pocket (my LHS doesn't stock BME, so no 110 []), of course the BME 105 has slimline mufflers with it also...

I plan to put whichever one in a GP 1/3 cap I got last year.

I have heard the DA is a bit stronger than the 105, and also been told that the DA, being heavier, will balance the CAP cap more easily. The balance should not be an issue if I lay other components out a bit more foward.

Thanks for the input so far, and please keep it coming. I want to learn all I can about any issues. Thanks!





By the way Silver, I picked up the Evolution 26 this weekend, thanks for the insight on the other thread that the silly moderator closed prematurely.

I get to many PM's and distractions to recall what I did, but you're welcome just the same.

You've got a hard choice ahead of you, especially with the strore credit in the background. Both are excellent choices, and I never let balance questions interfere with an engine choice if I have the options of moving equipment around. Forward or back, makes no difference to me[8D]

NIB with mufflers? Hmmmm.

I have two of them and love them both.
Just make sure that you baffle it properly and it should be just fine

Silversurfing if this happens what does it take to fix it?

If that has already happened the fix is to send it back to BME. It will cost some dough but the top end will be replaced or properly repaired. What happens is the pistons get so hot they leave aluminum trails on the cylinder walls.

Indications are low compression and lost peak rpm, seemingly erratic carb settings, and frequent stopping in flight. Makes for a very unreliable engine. There is a home fix if the damage is relatively minor but it is at best a temporary one. That's to remove the cylinders, look for traces of aluminum on the cylinder walls, and use muriatic acid (pool acid) to clean the aluminum off the cylinder walls. The cylinder must be removed for this. The acid will kill a piston real quick. Also clean out the ring lands of the piston with a suitable tool. A burned side on the piston is another indication that you killed it, and probably also have a stuck ring. I met a 115 this past weekend where it has already been toasted. Owner stated that (paraphrased) it got so hot the coating on the cylinders was burned off. Baffles and mixture again.

Not much acid, use a compatible brush, wear a mask, eye protection, chemical apron, elbow length rubber gloves, and have an acid neutralizer and chemical eye wash right handy should you spill or splash any on your person. If you think I'm trying to scare you away from doing it, you're right. Better to send it back. The bottom end is likely still good and the cylinders may be salvageble in the right hands.

thanks for the scoop

I've been running the 105 and realy like it. Its a great motor. I'm running a 26 X 10 on mine and it turns it great.

Silversurfers correct about the muriatic acid. It works, I tried it about a year ago
When the engine gets hot the piston expands more than the cylinder does. With all that heat and friction the aluminum from the piston is deposited.

Hopefully he will be at copper Sunday, I gotta see that.

Thanks for all the info everyone. It appears there aren't any leak issues or such, but there are some cooling issues (which I had thought didn't show up until the 110).

There really aren't any major "cooling issues" with one engine manufacturer over another. Some might be more sensitive to poor air flow than others, BUT all engines benefit from proper cooling/airflow.
The biggest benefit (besides a repair bill) is the increase in power over a hot running engine. I continually read about people complaining about how they need more power, which engine has the most, which is the best, etc..... On a hot summer day when density altitude and everything else is against you, I can guarantee you will notice the difference with a well baffled engine. I have done some testing with baffling vs non baffling and temps, there is a definite difference noticed.

On the 105, if I am not mistaken, they used industrial cylinders/pistons. They will probably be least affected (less critical need) by poor airflow. Larger clearances, more fin area.