bajaloya

Hi

I would like to know if the DA85 is a good engine to buy nowdays. I have read that it had some issues and them doesn´t look like very nice.
The engine´s propeller hub seems to lock in some of them, plus there are some trouble with the carburator´s screws. Please: this is not an attack, I do really looking forward to buy the engine, just wanted to be sure that those issues have been corrected. Thanks for helping. Alex

Supermod56

My Feedback: (36)

DA corrected the hub issue, they didn't have enough clearance between the case and the hub, all good now. When you get it new, seal the cylinder gasket with RTV to fix the "ooze" and check the carb screws once in awhile, just like on any other motor, they come loose after awhile

Tom

bajaloya

Do you mean to open up the cylinder head and seal it with high temp. silicom ? sorry what you mean by "the ooze"? Thanks!

badfish

a lot of the 85's develope a leak at the jug gasket. they have been playiing around with different gasket material and sealants to correct this. I should get mine back in a few days. being a big single piston engine it has its vibration issues. I've gone through some mufflers, had my carb bolts loosen, (which I heard they are replacing the alum. ones with steel.) and had to add extra cowl mounts cause mine kept falling off. (probably just my planes design) It does start up perfect every time. never had a dead stick. and tons of power for a 33% plane.
steve

k_caller

My Feedback: (1)

Hi,
what do you mean about the hub locking up?
I just bought a DA85 and put it on the test stand for initial break-in. First tank of 800ml went fine using a 26x10 Menz Wood Prop.
It started right up and ran very well for the first run.
2nd run was a different story. Starting was no problem but after about one minute, the prop flew off with all 6 bolts sheared at the hub.
I still cannot figure out what caused it. Needless to say, it has been returned to the shop for inspection and replacement of the hub.
Anyone have any ideas as to what caused this? My retailer says maybe it was caused by the bolts coming loose. I own a DA 50 and 100 and have never had this happen.
Thanks for any clues that might help prevent this from happening again. Even at idle you can't imagine how far a prop flies from an engine.

Flyfast1

My Feedback: (1)

I believe both issues have been resolved. I bought mine after the hub issue was resolved, but it came with aluminum carb bolts that loosened. I called DA and they sent me steel carb bolts have have stayed tight now for many flights.

Regarding the gentleman who had the prop fly off, perhaps the bolts loosened after the first run? With a wood prop they will need to be checked. It is easy to overtighten them and compress the wood.

I am very happy with my DA85 in a 33% Aeroworks Extra 260. It's a fun combination!

-Ed B.

Yakman2910

My Feedback: (6)

Maybe this is just a dumb comment but has any of you ever heard of using "LOCKWASHERS"!! Bolt's wont back off when locked in place with lock washers! Also blue lock tight works wonders. I own alot of DA's 50,85,100,150, never had a problem!

Yakman2910

My Feedback: (6)

Check your bolts after each run for the first 30 flights, use red lock tight and lock washers and you will never ever ever ..... have a problem. 20 years experience is the reason I know whatI amtalking about. If it could go wrong I have seen it. My job title is, First class, specialist, journeyman,nuclear,machinist! I make most of my specialty bolds and nuts and washers with my lathe and milling machine. Hope I helped! Thanks!

k_caller

My Feedback: (1)

yes, you're right. In hindsight, it could have probably been preventd if I had checked the prop bolts for tightness. I've been running the 40, 50, and 100 ever since they were produced and aavailble here in Germany and have never found a loose bolt. So as you say, I'll be sure to check them after every run. We use spring washers over here, I guess those are the equivalent of lock washers. Most loctite sold over here is Blue- red is very hard to find. What's the basic difference between red and blue loctite? Is red more permanent or...?
Thanks for the hints and ideas. Still waiting for my engine to come back and see what the experts say.

mrbigg

My Feedback: (21)

Red is more permanent and usually requires heat to remove. Use the blue.

Tired Old Man

My Feedback: (1)

There is no need, and in fact better to never use, any type of thread lock compound on a propeller screw. Those will be the ones you'll have to later cut off. Better to invest in an inch pound torque wrench and torque all the hub screws to 40 INCH LBS. Not foot pounds. The reason they shear is because they were either over or under tightened, or bottomed out because the maximum applicable screw length was not checked. One size does not fit all. Flat washers are all that should ever be needed between the screw and the prop washer.

Use the same torque on the cylinder screws for the 85.

Bill Mac

My Feedback: (1)

I have one of the first  da 85 s built It has always been the strongest engine Ive ever had ...The carb finaly started going have a replacement on oder .Just replace it with one from Da not a wanna be ...