Went to a swap meet this weekend and ended up with a MOKI 210 for $15 missing the carb HSN and muffler but otherwise complete. Thinking about converting it to the little 1/4-32 spark plug and EI but wondering if I should use regular gas and a bunch of oil or see if I can get ahold of methanol locally and run that?

Thoughts? I just couldn't pass up an engine that size for that cheap . Also got handed a partially converted Poulan 21cc and a handful of .20-.60 engines needing various little fixes.

Yes you can convert it to gasoline. If the engine has a bushed connecting rod, then you'll need to run a 20:1 to 25:1 fuel to oil ratio, using a good quality synthetic oil (much less carbon buildup). You will need to use a Walbro carb on it so that may require an adapter for it. You can get CH Ignitions or RCexl ignitiopn systems to use on it. This will entail drilling a hole for the magnet and gluing it in, and mounting the timing sensor in some fashion.  But other than that, it is no big deal converting one over to gas spark ignition. Just use regular grade gasoline in the fuel.

Now then some guys do convert their glow engines to use spark ignition and they still run glow fuel, so that is a viable solution too. In this case you could continue to use the stock glow carburetor on the engine. But with gasoline you have to convert over to a carburetor that can handle the more lean air/fuel mixture that gasoline requires.

Convert, but keep running on glow fuel.
Running gasoline requires larger cooling fins. Due to the very high specific power, you would need to run at least 10% oil as well, mainly castor, there are good castor based cart oils around) You need to provide good cooling ducts and baffling/jacketing as well.
BTW,  the crank pin cannot be used for needle roller bearings. The material is too soft at HB30-HB40. Needle bearings need HB60 or more (glass hard, cannot be filed)

I agree. A cool setup would be to convert it to a Walbro carb, CDI ignition with a 1/4 x 32 spark plug, and run it on Methanol/oil mix at the factory recommended ratio. Use a Walbro WT-499 carb. It is a good size for this size engine, and is made for use with methanol so it will flow enough fuel and have methanol resistant materials.

Then go "spank" some of the guys running DLE 20's. (Don't tell them you're running methanol, just to add insult to injury....)

AV8TOR

Don't tell them it's a 210 either

We can be "evil"..... Tee hee...

That's what I was thinking, methanol and ignition, I know the cooling would be inadequate with gas (teeny little fins on this guy). Wish I had the money/space for that USL 120 that was at the meet, I think that combo would have been nice . I think I have an idea for a carb adapter, it already has a pulse port in the backing plate so one step is done .

I do have some St Patric's day aluminum Bud Light bottles stashed from last year, so I think I need to do that for a muffler for this guy...

Carb swap won't be needed if instead of the missing needle, you install a remote fuel needle.
I have nice ones in stock, servo controllable in flight.

That's an option. However, check the venturi size of the stock carb. Glow carbs often have a slightly smaller venturi size than optimum because it helps fuel draw. With the pumped Walbro, fuel draw is not an issue. The WT-499 Walbro venturi is 11.1 mm. If that is bigger than the original glow carb, it will likely give you a bit more power.

AV8TOR

That should be an excellent choice for a carb on a 210 glow if peak power is secondary to user comfort.
http://www.davesmotors.com/s.nl/c.88...t.A/id.4131/.f

How so PE? I have not personally done the conversion of which we speak, but I do have a Super Tiger .90 converted to gasoline use, and a Walbro carb. I love the fact that the installation is not critical to fuel tank placement, and that the Walbro carb has a mixture "delta" of several thousand feet, which does away with constant "needle tweaking". I've had no problems with the setup using a Walbro carb, and the carb does add power with it's somewhat larger venturi than the stock carb was able to have to run reliably.

AV8TOR

At 11.1mm venturi the carb is excellent for low cc racing, like Zenoah boat engines of 22cc or 26cc. For the MOKI 210, which is 35cc with rpm up to 11,000/minute, the carb is getting smallish. Not too small though! It should be an excellent choice, like I said in my previous post.

Which prop should I go for on this thing with methanol, with my swap meet scores I've got a fair selection, but only a few different sizes/types in the 16-20" range

Also a thought, the only large plane I have in my stash that isn't complete is a Goldberg Edge 540 that I was going to run a 46cc Poulan on but now I'm thinking this guy would be a good alternative, thoughts?

A 20x8 prop would be about right, and it would fly circles around the Poulan.

After flying Moki 180s and have them pulling a vacuum in the fuel tank I cant imagine feeding a 210.[X(]
BTW Pe is very right about the crank pin, the only way to gas this engine involves a bunch of machining on the crankshaft to install a hardened pin.

I understand on the crank pin, don't want to go to that trouble on a $15 engine that doesn't have the cooling capability for gas anyway... if I decide to go that route, the machine shop we use through my work would probably help me out...

I think I'll give methanol a shot if I can get it locally (there's a couple speed shops in town), even if it's thirsty it should still be cheaper than nitro, and should be reliable on ignition.

OTOH, A new gasoline type crankcase with large cooling fins is about €40.00, a radial finned head is ~€16.00.

Does the cylinder head from the gasoline 2.10 bolt onto the the glow version and does it have the same combusiton chamber shape as to not affect performance? I have an installation where a bit more cooling fin area would benefit the engine greatly. Basically the larger fins would stick out into the airflow more than the stock glow fins.

The gas heads will <font size="4">probably</font> bolt onto the glow crankcase. I do not like to take apart my engines to check and make sure. Compression ratio will certainly be lower though, which causes glow plug selection problems unless you use extra nitro methane to compensate.
You also would need to use M10 to 1/4" plug thread reduction parts to cater for the glow plugs. I have these available, made by RCexl.

The nitro is no problem, I am used to 30+% in my YS four strokes. I did forget all about the plug size. My engine will be inverted so the plug might drown in oil more using an adapter.

Just buy the HSN you need and run FAI fuel. Muffler from Bisson or Slimline is needed either way. Gas version is Very different, head (bigger) rod bearing etc. We run 20x10 or 21x10 Bolly props and they really haul. OS F plug, very wet prime, flip backwards. Running in can take a gallon or two if its not already done. Try to rotate 15degrees away from fully inverted to avoid drowning the plug.
jp

I was told if you use E-85 + oil, you don't need to change to a walbro carb. *

Jeff