.

Try Scott for a apapter http://www.rcuniverse.com/forum/m_31...tm.htm#3995754

A G-38 hub fits. B&B has 'em. Horizon has 'em. Ralph probably has them. Wacker engines probably has them.

Joe Butch: thanks for that tip. I have a G38...never tought of trying the hub. YA-HOO!!! Capt,n

On the horizon site they list OLD and NEW adaptors for the G38.. which one is best?

You want the old one. The new one bolts to the flywheel. The old one threads onto the crank

MB290 Here is what prop end looks like. I have installed the cmplete G38 prop hub. I do not like the way it seats against flywheel...but good enough for a test.

Isn't that coil setup for the engine to run clockwise ?

Antique: When I pull starter rope...engine turns in CCW direction. Should work. Remember the flywheel is backwards...not like most engines???? Whay do you think its the wrong direction!!!! Capt,n

I disassembled my MB290 today. With the low airflow over the cooling fins when its in a blower, I plan on cutting the fins way down. It will never reach temp in an airplane, and I plan to use it in a sport plane without a cowl. I am also going to cut the case down and remove as much excess metal as possible. Hopefully reduce it a few ounces.

One thing is for sure, theres no shortage of screws holding that thing together.

How do you think this will work on an ultra stick 120?

I am going to do the same...make it loose weight! I got my MB290 engine ready to run. I checked spark with plug out. It was great just hand flipping it. I put the spark plug in and give her a good flip or 2. It fired hard enough to loosen the G38 prop adapter. I thought this may happen. Can someone give me the thread size of the shaft. I think it may be 8MMx 1.00. I got to know this for sure. I only got 2-3 precut, but not tapped aluminum pieces to mess up. Thanks Capt,n[:-] ....... Edited to add photo

I hope you realize that there is nothing holding the flywheel in place with the G-38 prop hub unless you've made some sort of spacer for the hub to bottom out against that we can't see in your picture.[sm=confused.gif]

You are sure right flipflop! I am going to make aluminum apapter. Or cut the spacer that is on there to correct length. The G38 did not seat because od the 2 bosses there. Another fix would be...is to remove flywheel and mill the 2 bosses out of there. Sure wish I had a mill and lathe. I had the use off all that good stuff at work. Now retired...and got to get more tools to do this kind of stuff.[:-] Capt,n

Got MB290 going. One flip starts. Did 4 starts in a row. Sounds great. Will post photo later. Capt,n Edit to add photo...with new prop adapter I made. The engine has a real good transition and good idle. Never touched the mixture screws. Caps still covering adjusting screws. Regars Capt,n

captinjohn, Iooks like you have a homey 25 on the bench in the back ground , has it been modifed also? tell us about it. Gryohead

Car54: I think the engine (MB290) would work well in a Ultra stick 120. Like any conversions you want to hacksaw & grind off any metal and other parts you do not need on engine. Gryohead... That is a Homelite 25cc Glow engine I am working on. I will post a photo. I am going to try 3 ways of running it. Straight gas....straight glo fuel and then a mixture of Gas & Glow fuel. I think straight glow fuel will produce most power. Capt.n

sweet.. can't wait to get the engine going. I completely disassembled it and began removing the excess metal around the flywheel, cutting the cooling fins down, machined the intake manifold to the same size as the carb and removed the round tabs that dont let it completely flow.

Prior to disassembling the blower, I put about 12 tanks of fuel thru the motor. It looks great, completely clean and no carbon anywhere. Just a slight black oily coating in the exhaust port. I am running Mobil-1 MX2T synthetic. I am impressed by the quality of the motor. It appears to be very well built and the carb was perfectly tuned from the factory.

More good news. I got my Sears Timing like out and tried some experiments. The light would not work at first. Took it apart and cleaned trigger switch. no go ..only a blip once in a while. I happened to touch the metal body of the light to the engine...it started working. So I added a ground wire I just clip on. Works great now!!! I have found out the MB290 does have some advance when you rev it up. It appears to be about 3/16-1/4 inch travel. It has a 3 1/2 inch diameter flywheel. How many degrees that would be can be determined. it does have advance for sure...and thats a good thing. I have not set the carb mixture at all. I got to make a adjusting tool. Tonites project. Ha! Like "car 54" says...the carb is set close. I think top end needs to be set. Idle is perfect. This engine will hand start better than any engine I have owned. 25 hand starts in a row!!! no 26 I did not flip it right! Take Care Capt,n

Capt’n,

Thought you might like to know the two blowers arrived today. I have one apart and am attempting to decide how to mount the prop. They appear to be very well made.

Based on 3/16 and 1/4” the advance would be 6* 9’ and 8* 12’.

Bill

Bills: I used round stock aluninum. Cut to lenght you want and square it off in lathe. Drill through with a 'J" drill and tap with 8MMx1.00 from both ends. Do this in lathe to keep things in line and on center. Very easy. Run tap in with tailstock chuck. Turn chuck by hand when tapping. Use some cutting oil. Take a look a the last phot of my engine...thats how I did it! Use locktite on threads. Good Luck Capt,n

Capt’n,

Your prop adaptor looks good. Thanks for the very good explanation. Unfortunately I don’t have a lathe and am looking through my collection of stuff to find something that might work.

For what it is worth the original blower weight is 8# 4oz. After parts removal the engine weights 4# 4oz with muffler, pull start, and no trimming. The muffler weights a half-pound.

The exhaust opening on a ST 2000 muffler to engine mount is identical. For experimentation with mufflers or pipes an adaptor plate could be made.

Bill

3.5 diameter x 3.14 = 10.99 inches
10.99 inches is 360 degrees, 1 degree is .030 on the circumfrence of the flywheel
The ideal 28 degrees is .030 x 28, .854 total movement from idle to WOT..
The formula works out to .244 times any diameter...244 x 3.5 = .854
If the movement is .250 you're getting a little over 7 degrees retard for starting..
With this information you can put the flywheel on the crank so the timing is 28 degrees, if it is not already there [8D]
The key is not necessary, it's just there for engine assembly..The fit on the taper keeps it from moving..Just put the hub on TIGHT..A few drops of Loctite on the shaft will ensure that it won't move.....

RCIGN1: Your are da man. How did you know I was going to do just that.? I did not have the formula...but I did remember you explaing about loctite to hold the flywheel on so you can set the timing where you want. Thanks again. Have a great, Capt,n

Bills: Get rid of the muffler...its very heavy. The recoil is the only cheap part I found. Get rid of that also and the part that botls on end of crank for recoil. Yo will not need the recoil starter. Also keep looking ...there is a lot of extra metal that can go bye bye. the backside of the flywheel fins....just dead weight. When I get done with mine I will post a photo. My 2bd blower is faster from the start. So I am going to put the 1st one back together and strip down the 2nd one. Take Care Capt,n