Simple carb rotation plate
 

Hello everyone,
I recently wanted a straight shot rotator manifold for my Homelite 33 chain saw engine, but they aren't available. So I created a rotator plate, complete with pulse port to meet my needs. It is made of 1/8" aluminum, since that is the thickest that I could get at Home Depot. It is attached to the stock manifold with two 6-32 allen screws and washers, plus locktite. Don't forget the extra gasket with hole for pulse. I attached pictures of the rotator and carb screws modified with a dremel. If you use the idea, let know how it worked out.

Dave

RE: Simple carb rotation plate
 

Nice work. However, it is so easy to tap the pump top on the carb for a fitting, and then tap the case somewhere convenient to run a tube for the pulse to the pump that I never mess with the original pulse port when I change things around. Also, the pulse hole is often in the way when I open my manifolds up for bigger carbs.

Thanks for the pics,
AV8TOR

RE: Simple carb rotation plate
 

Hi,
You are right. The reason that I made the pulse channel was to show how it is done and for the challenge. This manifold already has a 5/8" bore, so the clearances for the hole were fine. Thanks for the feedback. It is always helpful.

Dave

RE: Simple carb rotation plate
 

I have rotator manifolds for Homelite 33cc and 38cc engines. They are custom made for Walbro carbs. I would sell you one for $20.00. I convert Homelite engines and often have them listed here on RCU. Here is a link if you are interested in seeing one of my manifolds on a Homelite 38cc engine.

FYI: I also have the following conversion parts for Homelite engines.

rotator manifolds for the 45cc Homelite with the round style intake.

Aluminum Engine mounting rails

Polished Aluminum Prop adapters with counter threaded prop bolt for using Aluminum spinners without the need for an adapter.

Polished Aluminum Mufflers

Gaskets, Piston Rings, Cap Screws, Carbs, Ect.

All of my parts are the highest quality you will find! I have a very skilled machinist who uses a CNC mill and lathe to make my parts.


http://www.rcuniverse.com/market/item.cfm?itemId=110400

RE: Simple carb rotation plate
 

What I would really like to know from you if you wouldn't mind sharing, is what carb you are using on that Fuji engine. I have a Honda GX31 that I'm getting ready to convert, and I've been questioning people about a larger carb for it. When you adjust that needle, does that adjust both the low and high end mixtures??

Thanks in advance,
AV8TOR

RE: Simple carb rotation plate
 

Hi AV8TOR,
You might know already, but the stock Fuji 24cc and 34cc both use the Walbro WT-690. I don't know the venturi size though.

Dave

RE: Simple carb rotation plate
 

Hi,

No, I noticed in your ad for your "Fuji clone" that you are using a larger 12mm carb on your conversion. Which one is that, and where/how much to buy one? Also, how is the high and low mixture adjustment handled?

Thanks again,
AV8TOR

RE: Simple carb rotation plate
 

The carb that Fuji uses on thier four stroke engine is basically the same carb as what is used on a Zenoah G-26. It is not the stock carb for this engine. The reason they use that carb is its easier to adjust high and low needle settings. The OEM Stock carb for the Fuji engine is actually a Walbro WY carb. This engine is actually a high end string trimmer engine. I have upgraded to a larger series Walbro WYT Series carb. I have a detailed 4 page repair manual from Walbro on this carb that details the adjustment.

Just about any Walbro carb will work for this engine.

RE: Simple carb rotation plate
 

I have 6 of these WYT Walbro carbs and they are brand new and never seen fuel. I didn't intend on reselling tham as with my other conversion parts but I do happen to have a surplus of parts so I will sell one for $40.00 shipped. I will include a copy of the repair manual with it too.

RE: Simple carb rotation plate
 

The venturi on that carb is 11.1 mm

RE: Simple carb rotation plate
 

So how come the WYT carb is not in the 2005 Walbro price book or anyhere on the Walbro website...Secret project maybe ?
You think Luis Salas at Walbro might know of its existense ?:)
Stock carb on a G26 is a WT645, 12.7mm...

RE: Simple carb rotation plate
 

My mistake! Its a WYJ carb. :eek:

The exact stock carb on the Fuji BF25/34 Engine is a Walbro WT690 and I believe it is an 11.1 mm venturi. RCIGN1 may correct me if I am wrong.[:-]

However I retract my statement about it being the same carb as the Zenoah G26. It is not the same carb but is very similar.

RE: Simple carb rotation plate
 

av8tor...
have you converted that GX31 yet? I would like to know the distance from the mounting plate (firewall) to the back of the prop. I am considering a GX31 in a 1/4 scale fokker DVIII but need to know some dimensions for fit.
Thanks, Bob