Im currently converting a Poulan 46 and have read somewhere that the prop hub from a Zenoah g38 will bolt to the flywheel of the poulan.Can anybody please let me know more about this.It sounds alot better than a threaded prop hub sense there is only about a half inch of 8mm thread there.Brillelli says there dangerous and can snap off.[:@]Anybody tried this yet with the g38 prop hub?

What we do is drill and tap the 2 holes that were used for the recoil catches to 6mm x 1.0. Face and true up the flywheel after it is milled to remove the fins. We have a crank cut off that we clamp in the lathe to be sure and get the face perfect in relation to the crank. The hub we make for our 46's slids snugly over the origional flywheel nut and than the 2 6mm bolts hold it in place. If you look at the origional flywheel nut it has a sholder on it past the hex that is machined. That is what we use to locate the hub. We do not use the washer because it is not flat and will make the nut sit slightly crooked. By making the hub this way the entire crank takes the stress and not just the 8mm threaded end. We did have a crank snap off with a screw on hub. That is why we came up with this. On a smaller 25cc or so engine it is not a problem. Just on larger engines like the 46.

Ok so you poco242 make a prop hub thats similar to the Zenoah g38.Thats cool and everything but,my question was will the Zenoah hub work just the same.It uses a round rotor nut that it centers on just like yours does.I believe the diameter of this is about the same as the shank on the poulan nut.If not this is a easy fix either further machining or (drilling).or a sleeve for the shank.Either way,I believe the holes line up perfectly to the predrilled in the poulan fly.I guess the bottom line is how much is your fly going for?The Zenoah is only $19.00.

The new prop hub is on the way.I will post further when it gets here and post pics of what I did.

Looks like you installed studs to hold carb on? Cut down flywheel and balanced it? Looks real good so far. Capt,n

I am not sure if the G38 hub will fit, but for the price it is worth a try. FOr that price i may have to start using them It is not worth over an hours work to make them if that is all they cost. I will be watching to see how it works for you. That type of hub setup on a mag engine is the way to go for sure.

I looked on Horizon and the hub is $24.99, Washer 7.99 and prop bolt $2.99 so the total for the setup is $35.97 plus shipping. We charge $45 and it comes with a machined and ballanced flywheel.

I did'nt buy from Horizon Hobby.There is a rc hobby store on ebay that sells these parts.The hub was 19.00,the bolt was 2.99 and the washer was 5.99 so about 33.00 bucks with shipping.I don't know if he is getting more of them but here's the store name, FischelsHobbyCenter And you have a very good price if you include a machined and balanced fly.I would be real cool to have the fly and the hub as a one peice item with a bud style lug where the prop bolt or stud would bolt to the inside of the lug.Here's a little drawing.not the best.Thanks Poco

Captinjohn ,Thats not a stud,its the nipple for the carbs pump.Im currently looking for a manifold for this engine.I know CH Ignition has a nice one but,its made of plastic .I think im going to design my own type of manifold thats bolts to the flange at the base of the intake port,made from aluminum of course.I will post later when I get around to it.Thanks Captinjohn

Aluminum transfers engine heat to the carb. Does not work very well.

What is the diameter of the intake stub on a Poulan 46? Why not take a 90 degree high temp tubing (silicone rubber) and make a manifold to put carb in better position. It would be easy to make a aluminum flange that carb bolts on. The flange would be welded to a simple piece of aluminum tubing the right dia that pluged into rubber manufiold at carb end. Pluse line could be attached to a nipple at each end. just a idea. If I had a 46...I would try it. Capt,n

The stub is oval...Look on rcfaq.com...It shows 2 ways to do the carb manifold...One's my way

Iv tryed to find some epoxy board but had no luck,All companies want to sell a very large sheet.Any ideas on where to get this stuff.I understand your point now about the aluminum tranfering the heat to the carb.A composite material makes sense

There are 2 different G38 hubs..The one that works on the Poulan is the old original one...The original hub was used for about 15 years...It was steel...It threaded onto the end of the crank and also held the flywheel on...A few years ago it was changed to the new style aluminum hub that bolts to the flywheel with 2 6mm allen bolts..The flywheel is held on the crank by an 8mm nut, same thread as the old steel hub...It worked that way for at least 15 years before the update...I have seen many bent ones but have not seen one that broke off..The steel hub bends and the threads on the end of the crank bend, but so far no broken ones...

Yup...sure is oval allright! Forgot that detail. Rubber connector still might work....if the stub is long enough to slip a connector on and use a good worm gear clamp. Capt,n

Im going to be using the new style hub that uses the poulan hub nut which has a flank that will fit in the center of the Zenoah hub.Then the two bolt holes on the poulan fly line up with the two holes in the hub to better secure the prop.mounting just on the half inch of 8mm threads is scary.[&:]

Well Iv drilled,taped and installed the pulse nipples in the carb and the block.Tomorrow I will be getting the aluminum plate to fab the manifold base.This will have a heat shield of plywood or some thick gasket material like automotive carbs use between the carb and manifold.Will post pics as I go.[sm=thumbup.gif]

I too am anxious to see what you do with it. Please keep posting pics. It is a great engine- very powerful.
I have been wanting for a more permanent way to fix it than the FRP and silicone approach.
They just didn't give a whole lot to work with there with that short stub. Ahh- the chainsaw price wars....
I'd gladly pay another few bucks for a real carb flange.
I would prefer to fabricate something metal- with a heat shield spacer between it and the carb.

Yeah,I don't really like the permatex and set screw idea.Thats why im getting ready to fab a manifold that attaches to the base flange of the stub instesd of the stub itself.Got the plate today at local scrapyard ,$1.50.Will be working the plate later this week.will post pics.Thanks,

Well while waiting for the hub and stuff to get here.I decided,actually could'nt wait to start the manifold I decided to make.cutting the t6 is a b___ch[:@],but I got'er dune.first I cut the outter diameter of the manifold and positioned it on the engine and marking the stub cut out.I then cut the stub hole to where it fit good but not tight.I then marked and drilled the three flange holes where the manifold will attach to the base of the stub.After drilling the holes for the machine screws I oversized to a 1/4 bit to counter sink them about a 1/4 inch in the plate.I noticed that I did'nt really have much flange for the hole(the outside edge was at or over the edge of the base).So I decide to make two backing plates that fit rather nicely between the cooling fins and base backside,one on each side.The center hole was no problem and had plenty on meat for threads right next to the old pulse port.After drilling and tapping out the backplates and center hole I mounted the manifold with 6-32 stainless machine flatheads and marked the carb mount holes to the right of the oval stub where the right side of the venturi and the right side of the stub were even.The reason I did this is because the carb has more sealing surface on the left side,I don't want any leaks.I use and old carb bolt to make a tap the proper size(grind for sides tapering towards the end)Im using bolts right now but,will be using studs later.I then used the old metal plate that was between the carb and rubber poulan junk and marked a heat shield out of 1/8 lite ply.This is a tight setup and I feel like its much more secure than set screws on a cast stub.Here are the pics I took along the journey.Any questions I will be glad to answer.

Another thread same problem. Material Search : G10 Garolite strip at McMaster-Carr
Twister manifold and 11.11mm carb
http://www.rcuniverse.com/forum/m_28...tm.htm#2806428

Well obviously the mail is slow due to the god aweful heat.Still waiting on the hub and parts etc.Decided to finish up the manifold job and show it to the guys at the hobby shop in Richmond."Its now official",This is to this day the best and most secure way to mount and twist the carb on a Poulan 46.I finished it up by taking the manifold down some more in size(diameter)without compromizing the gasket area.Then I polished the outter diameter and flange surfaces.Cut out a fel-pro gasket set from a old Pontiac water pump set that I had laying around in the toolbox.I made two gaskets identical to each other for the manifold to base area.I use VarsaChem #2 gasket sealer/maker on the engine case/crank case.and on the gaskets for the manifold.Permatex when invited to gasoline tends to turn to jelly and squoosh out.VarsaChem #2 is a non-hardening sealer made for metel to metal or metal to gasket etc.and can withstand gas,diesel,glow etc.After tightening the manifold down pretty snug I installed the plywood heat shield and carb with no sealer.Tighten down just enough tell you see the carb making an impression in the ply.After all assembly was finished I tested the pulse line and it has plenty.......[sm=thumbup.gif].Im now ready for the prop hube and prop and all the other stuff I ordered five days ago.Until then what do you guys think so far........

Well today I got the prop hub,prop washer and bolt.As soon as I pulled it out of the box I knew it would bolt up to the Poulan fly.I also noticed that the hub pilot hole was larger than the poulan flank nut shaft.I thought to myself "this is going to be a cinch".I don't have a machine shop nor do I have free access to one.Everything Im doing here is by hand with high speed drill and the mighty dremel.I needed to make a bushing to fit the fly nut with clearence for heat expansion when fitted to t-6 alloy.Steel expands alot where alloy expands a little if any..003 is minamal for this app.I started by tapping out the two holed for 1/4-20.I would have went with 1/4-28 but 20 has a better and larger thread.Fine threads usually dont last long in cast aluminum.After tapping I set the hub on the fly and the holes were dead on,perfect,like the were made for the Poulan.I then started with the bushing with a small piece of t-6 alloy.I get all my metal from wick aircraft supply,best prices and fast shipping.I marked the center and drilled with 1/4 bit.This next step is actually not recomended unless you know what your doing.I use a prop balancer in the dremel to spin the plate but dont allow the max rpm's, when starting have the bit right at the metal to start cutting.I use 1/2 inch carbon drill bit to do the cutting.This works perfect and Iv done it before cutting downsomething,can't remember.
Anyway at least put on your safty glasses and were gloves just to be safe,also try to keep the pets away.My cat was actually supervizing this job.LOL.I cut the outter diameter down pretty quick,when starting to get close to the right size stop and check the fit more often.I ended up making two because the first was about .020 to small.After getting the outter the snug fit in the pilot hole I then removed it from the balancer.I installed a bolt the same size as prop bolt through the backside of the hub,so that it was threads on the prop side.This part goes in the high speed drill.I then installed the bushing in the fly side in the pilot hole.Now were doing the inner side of the bushing and using a smaller diameter bit,1/4 worked for me.Make sure its a carbon and not a high speed cheapo,they will burn and dull easy.when getting close to the right size,I put a carbide bit in the dremel and at the same time spin it with the drill and cut it even with the carbide spinning in the dremel.when this fits slightly loose on the nut shaft your done.I used .003 clearence for this app.The Zenoah hub is very light because its hollow and being hollow actually makes it stronger than solid hubs.Heres the pics and I will gladly answer any questions.This hub works and looks great.

Very nice job.....but I bet you wish you had a lathe! Right? Capt,n

Very nice job- most likely the best I have seen. Your gonna have a clean looking powerhouse with that one...

TIGITRIGHT: I like how short the total distance from engine to outer edge of carb. Seems like a lot of adapters I have seen are way to long...placing carb to far out. Ever consider making and selling adapters? Thanks Capt,n