Hi All,

I am doing a little research regarding a 3W 200b2 TOC engine I have been asked to look at. In checking out the forums I've seen that this engine may have some issues. What is the story and what if anything has been done?

Best Regards
Carlos G

Carlos,
The earlier 200's had problems w/ the crankshafts breaking. They were using the crank from the 150's and the 200's just produced too much power. 3W has corrected the problem by replacing the crank w/ a newer beefed up version and also replacing the hub w/ a new 6mm version.

They will warranty the crank replacement but you would have to pay for the new larger hub. This motor puts out gobs of power and torque is out of this world. Once these updates have been performed the motor is as good or better than any in its class.

Hope that helps.

Hey Carlos, you planning a comeback ? The Aerrow 200 flew Fred's NA50 246 mph last year...Went so fast they changed the rules, the NA50 is now limited to 150cc
My race pilot flies 3W 200s in UAVs, PM or call me for his number..

My 200 has not been the runner that I had hoped. 3 gallons thru and got tuned what I thought was great. 15 dead stick landings later all less than 1/3 tank and much less and now it won't even start. I can prime and run on the prime but no gas from the carb. Cleaned the screen and inspected diaphrams Soft and Pliable with same results. I'm stumped!

It WILL work after it leaves here Monday or Tuesday...Or else [>:]

Hi All,

Well according to my friend, He has sent the engine back to where he bought it (It was New) and it was checked out and was supposed to have been ported and balanced etc. He says he still only gets about 5 to 5.2krpms with a 34/10 3W prop.

The 3W literature says this is about the smallest prop they recommend. Hes is running the Johnson Cannister Mufflers. He has tried other props but the engine has not responded well to smaller props, i.e., doesnt really turn up.

Hes is an experienced modeler and has other 3W's that run just fine. So he asked me to take a look at it to see if there is anything there that he and the people he bought from might have missed. He is getting the ignition modules checked out then he forward them to me so that I can run it to see whats going on.

I thought Id pick the brain pool of RCU to see if there was any "History" or remedies that people have come up with for this engine.

Ralph, Give me a call at home ( its still the same number) or email me with yours and I give you a jingle.

Best Regards
Carlos G

you need to use a 32-12 prop, my 200 rips a menz. Now using 32-14 3W carbon, thinking of going back to the 32-12 untill it has broke in some more. 34-10 too big.

Sent engine to RC Ignitions and the case is leaking air, the prophub is turning and breaking the key and jacking the timing, combo of these and it haS run lean enough to leave aluminum on th cylinder wall. I wonder if the steel hub was the fix for the hub turning. Ralph will fix her up. Thanks Ralph. I would not at this time recommend the 200 until I have seen this one run for a while. [:'(][:@][&o]

The hub on this one is aluminum with 6mm prop bolts..The tapered part is pressed into the center and didn't move, the hub moved enough on the crank to shear the key...No problem there, it's not thick enough or hard enough to keep the hub from slipping if it's not tight enough...I will get some fine valve grinding compound and mate the hub perfectly to the shaft, heat it a little, put some 680 green Loctite on the taper, and use FORCE to tighten the nut...
The cases on 3Ws are held together using 6 bolts on the 200...The 2 on the front are 5mm, the other 4 are 6mm..One or more of the case bolts are close enough to the inside of the case to leak case pressure if no sealer is used on the threads...This one had only 1 close that way, and it showed a very slight leak under the head...Some Three Bond 1104 on the bolt and case joint will fix the leak...
The rear cylinder had gotten hot enough to almost stick the piston, some skirt material was deposited on the bore...A little swimming pool acid on that fixed it, a few turns in the bore with a silicon carbide ball hone smoothed it out nicely...Used a 3M fine deburr wheel on the piston, good as new....
All 3Ws have a mark on the hub and case corresponding to TDC...If you're having mysterious trouble with a 3W, put it on TDC and check out the marks...They run really bad if the hub slips on the taper

Hi All,

I had a look at the 3W in question. The timing was ok. Set the piston at TDC and the magnet was where it was suppose to be. The marks on the case lined up with the prop hub.
Kevin at A.I. suggested I look at the reeds to make sure none of them were damaged, they were ok. I did do a compression test on this engine and the leading cylinder was 135psig. The other cylinder was 160psig. I was using a Snap-On Compression Tester with a 10mm adapter. Hmmm....

Does any one know what the compression should be on a good running 200? Kevin at A.I. didnt know. I called Cactus and spoke to Bobby and he said most likely it was due to being a low time engine and over propped that was the reason for the difference. He suggested running a 32-12 until the engine has had time to break-in ( about 10 hrs).

I did not tear down the engine because it is still under warranty. I left it up to the owner as to how to proceed. Only time will tell.

Carlos G

Got my engine back from Rcingnitions and it ran but had low end carb surging and dieing. Was kinda discouraged and then thought about my DA 150 that needs to be sent in for crash damage. I took the carb and swapped it. Good fit and I did have to open the gasket a little where the pulse hole is. The engine started and ran through the high to low end pretty well. Took it to the field and did some minor adjusting and flew. This is the first flight out of 15 that the engine ran the whole tank without stopping. Did a litlle more tunning and flew again. It was O.K. all the power is between 1/2 and 3/4 throttle with less than 200 rpm btween O and 1/2. Will have to get used to it I guess. Any body got RPM # for top end? I tached 5680 on 32-12 PT prop. Can more be had with the original carb? Is it worth it to buy another Tillotson carb or just stick with the Walbro carb fron the DA? Hello is anybody out there???????????

Hi Skreamer,

If the Walbro is working for you I would stick with it. Do you know what Model Walbro it is? Another item Kevin from A.I. mentioned was to avoid placing a fuel filter between the fuel tank and carb. Kevin believed it would restrict fuel flow to the carb.

I would also look at your fuel tank fittings and lines. You may wish to go to the next size larger lines and brass tubing on your fuel tank. These bigger engine gobble alot more fuel and need good fuel flow to carb. 1/8th tubing and lines may not flow enough fuel for your engine.

I havent had a chance to run the 200b2 and I think my friend is going to collect it soon so he can bench run the engine to break it in.

Skreamer if you get a chance please do a compression test of the engine and post it here. It would help out to know what the compression is to get an idea what an engine in good condition should be.

Thanks
Carlos G

Ralph did a compression test said they were within 20 psi of each other maybe he could chime in here?


I would like to know others that have a 200 what top rpms they have with what prop? I guess there must only be two owners out there that suscribe to RCUniverse and I'm one of them.


G202Pilot any rpm #s?

Is 5600rpm low?

It wasn't compressioj, it was the temp, about 20 different from side to side..
One side will have more compression, it had a scuffed piston and cylinder...I cleaned up the piston and cylinder but didn't have new rings to install...The piston clearance in this one was around .004, slightly loose by most standards....

Have run my 3W 200 for 2 hours---Below are the RPM's---With my 45 Lbs Comp-arf Super Extra the best pull was with the Fuchs 33x12 turning 5250.

3W 200 B2 Engine RPM's with different props:----

1] Fuchs 34 x10 4900

2] 3W Wood 34 x10 5500

3] Fuchs 33 x12 5250

4]ZDZ 34 x12 6200

5]Mejzlik 3 blade 31 x 12 5700

6]3W Wood 34 x12 4750

7]Fuchs 32 x14 5050

Thanks for the info. It sounds like my carb is in the ball park seeing the diff in all the props.

Depends how ya want to run it

Any others? There has to be more than 3 runnning 3-w 200 in the world. [X(] Maybe not.[:@]

There's another one out there somewhere, I have the broken case here....

Hi,

I have two of the 3w-200s.

Biela 34 x 10 = 5000-5200 rpms

Biela 33 x 10 = 5400 rpms

32 x 10 = 5700-5900 depending on brand.

Elson

Not to throw salt in anybody's wounds, but for $1,495.00 you can get a Kroma180 and for $185.00 mufflers for same. I just switched mine over to synthetic and it turns an NX32x10 at 6,200 on the ground on a 90F day. I am sure it will pick up a little more as I start to lean it a bit.

DKjens

DKjens No wounds here! (cause its running)[sm=teeth_smile.gif] Well thats five running 3-W 200 and more info on the prop. Thanks for the replies. You would think there would be at least ten of these in the world.

Learnt something very important from my 3W 200 after running this 14 hours with a Mejzlik 32x10 at 5650----Being a Twin Spark engine the Low Idle rpm of 900--Superbly smooth transition--Flat mid-range--very reliable throttle response---are characteristics no Single Spark engine comes even close to.For aerobatics/IMAC making say 1500 feet vertical downlines at idle and then increasing throtle at a point when the engine goes naturally rich/drowning--- these characteristics are worth their weight in gold.
Have ordered two 3W 170 Twin Sparks----Will not fly Single Sparks.Incidentally have flown Single sparks over 350 flights.