Zenoah 230 vs 231

I have been given a 230 zenoah. Whats the difference between the 230 & 231. ? is it possible to convert up to a 231? or would it be better to go to 260 specs?

Phil

IF I remember correctly, the main difference is in the number of transfer ports, a 230 having 2 and the 231 having 4. As for upgrading to the 260, I THINK it's also a 4 port engine and can't be upgraded in that way. I would expect that if Im wrong, one of the engine guru's in here will correct me

The 230 is a two transfer port engine the 231 is a 4 transfer port.You can upgrade the 230 but will need a case and top end with water cap and piston.The rest of parts will interchange.Crank starter coils flywheel.Gizmotors has a cylinder with piston for around 40 but will need a cooling cap ,cases ,gaskets and spark plug.Be best to get the larger carb also.

I believe the bolt pattern is different on the 4 transfer cylinders. We made hybrid engines using the 230 crankcase and the 2 bolt, 4 transfer cylinders by elongating the cylinder bolt holes and cutting the gasket and case to match the new transfers. You might as well upgrade to a bigger bore if you want to do this modification. The two bolt cylinders have problems with the bolts loosening.

Lohring Miller

jff,

i'm certainly not an expert but the zenoah engine designation numbers are confusing. basicaly, the first things to look for are the size of the spark plug thread diamter, 10mm or 14mm and number of cylinder hold down screws, 2 or 4.

engine experts please correct or add to the following :

the 14 mm spark plug "socket" wrench size for the old 23cc, 2 port engine is larger than "socket" wrench for the current 10mm spark plugs in the 25.4cc "G26" engines. i can't remember the dimension across the flats of the hex.

the "original" 23cc marine engine was designated G23PUM, 14mm spark plug, 4 cylinder hold down screws and 2 transfer ports. (the factory shipping boxes had G230 PUM markings as i recall)

later the air cooled G230RC 23cc, 10mm(?) spark plug, 2 cylinder hold down screws with 4 ports was being converted to marine use by removing the cylinder fins and adding a water jacket. to my knowledge the zenoah factory did not offer a water cooled version of the G230RC. these engines were being developed by engine "builders" like bruce hanson and many others.

sometime in early 2000's the 4 series engines were released by the zenoah factory. i have an ad from model airplane magazine, april 2003, about the new G26 air cooled airplane engine. the water cooled marine versions arrived about same time.

the new 4 port engine series included 2 marine versions, the G231 PUM and the G260 PUM, advertised as the G231M and the G26M. numbers on factory shipping boxes were / are G231PUM and G260PUM, i think.

regardless, the current series of engines are the 231, 23 cc, 4 port engine with 1 small identifier hole in rear side of the bottom cylider fin. and the 260, 25.4cc, 4 port engine with 2 small identifier holes in the rear side of the bottom cylinder fin. both engines have 4 cylinder hold down screws.

you asked about a "230 engine", so first thing to do is identify exactly which engine you have. number of cylinder hold down screws and spark plug size are first clues.

i suggest that if you have one of the 23cc engines leave it as is other than basic rebuild. don't bother with conversions. or get a new fresh stock "231" or "260". best bargains out there, in my opinion.

good luck,

dave

Firstly Happy New Years to All. Thanks for your replies. Theres alot of help here and I'm grateful for it, But the more I read the more confused I'm getting. The motor I have has a sticker on the bottom of the case thay reads"G230PUM No.602038". On reading this I guessed the motor is a G230PUM. The case has two transfer ports(one above each side above the crank, It also has four bolts to hold the cylinder down which have a spacing of 1.34"(34.1mm) x 1.52(38.8mm). The spark plug is a NGK R BMR6A which is a 14mm Plug.

Sorry for the confusion but, I really appreciate the help.

Phil

just for fun said:

Firstly Happy New Years to All. Thanks for your replies. Theres alot of help here and I'm grateful for it, But the more I read the more confused I'm getting. The motor I have has a sticker on the bottom of the case thay reads"G230PUM No.602038". On reading this I guessed the motor is a G230PUM. The case has two transfer ports(one above each side above the crank, It also has four bolts to hold the cylinder down which have a spacing of 1.34"(34.1mm) x 1.52(38.8mm). The spark plug is a NGK R BMR6A which is a 14mm Plug.

Sorry for the confusion but, I really appreciate the help.

Phil

Click to expand...

You can convert..but you gotta be handy with a dremel to open up the transfer ramps in the case..and even then, its hard to get em to really match up. You'd be better off buying a new case ($35 with seals & bearings) and a 260 topend kit and swap everything over.

just for fun said:

Firstly Happy New Years to All. Thanks for your replies. Theres alot of help here and I'm grateful for it, But the more I read the more confused I'm getting. The motor I have has a sticker on the bottom of the case thay reads"G230PUM No.602038". On reading this I guessed the motor is a G230PUM. The case has two transfer ports(one above each side above the crank, It also has four bolts to hold the cylinder down which have a spacing of 1.34"(34.1mm) x 1.52(38.8mm). The spark plug is a NGK R BMR6A which is a 14mm Plug.

Sorry for the confusion but, I really appreciate the help.

Phil

Click to expand...

For money spent, BEST deal around is getting take off parts from Mitch at Quick Draw.

They sell a set uf 260 cases, 260 cylinder/water jacket, screws and gaskets for less than $50

You need to buy a 260 piston/ring and bearings/seals to complete the swap.

You can use Crank/Ignition/Starter/ carb off your 230. All said should be able to do the conversion for @ $100 in parts. ( labor you provide )