For four strokes it's the [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXDG61&P=ML]Perry Oscillating pump.[/link] Not sure if it has a 'V' number.

A dubro soft mount will cause the problem to worsen. Furthur more the Dubro soft mount may even increase the vibration to the airframe as well. If you can attach the outlet end of the muffler solidly to the airframe using a bracket and a tapped screw hole in the muffler I think that will solve the problem. I notice in your setup on the Venus the muffler exits close enough to the frame that a small metal bracket could be fabricated.

The setup on the Venus has been fine sofar.

On the Ultimate I have an eye screw in the firewall and some copper wire wrapped around the bottom of the muffler and through the eye screw to resist the turning??

Someone also sent me some washers that have raised ridges on each side that will go between the head and the lock nut. That will allow more friction.
I think with one of those and some red locktite I may have a solution.

I'll keep you posted.

I use Teflon tape on the threads of ys 110 muffler to prevent it from unscrew itself during flight. It works just fine.

Can anyone post a pic of their Perry Pump mounted in the Venus? I'm lacking creativity these couple of days...

Hey Codfish, I had a brand new Saito 100 that broke two mufflers and when the muffler broke lose, it breaks the cylinder head, after fixing it twice, Horizon said they would not fix it again if it broke again and of course IT BROKE AGAIN...so I have a POS Saito 100 in a bag, I have used O.S. engines since then and have had absolutely no problems. Everyone talks about how much lighter the Saito is than the O.S. but the O.S. is a dependable work horse vs. a fragile engine that keeps breaking. And Saito/Horizon said the same thing, they never heard of this happening ever before...[sm=lol.gif]

Chuck,

You sure got the dirty end of the stick with Saito. I’m sorry to hear about that. It’s no surprise to me since I also found out the hard way with Saito’s support. I'm surprised they even fixed it 1 time for you. Did they charge you for those repairs? It is my opinion after dealing with Saito, that they have no intention of standing behind their engines. Their stance on support and warrantee puts them in a shaky position in the market especially in hard economic times. And more so when competitors like OS have shown to stand behind their engines. Don’t they realize that each time they turned away from providing reasonable support it costs them far more in bad press than the money they might save in denying good support? In my experience and others I speak to, OS has taken the opposite stance. Make the customer happy and you will be rewarded with stronger market share. OS has flaws as well, but the big difference is how you get treated when you have a problem and return to them for help.

Cod

Joe,

I posted a few pics of the perry pump mounting in this forum. I just cant find which page they are on!

Lazy Cod

Between your laziness and my blindness...

Thanks Cod, I'll look again

Edit: Thanks, page 25. Not doing the same thing, but just what I needed for an idea.

Chuck.

This is interesting. Over the last 4 years I have sent Saito Service one of my 6 Saito engines EIGHT times. Only once have they charged me for the repairs and that was for a severly damaged engine. That time the sold me a new Saito 150 at half price.

They have, everytime, checked out my engine and called me with the diagnosis. On every occations they have replaced the bearings and fixed any other problem and returned it to me without charge.

I have returned every engine with a copy of the bill of sale showing that it was in the warranty period and a complete description of the issue. I have never had a problem. With me their service has beem remarkable.

Obviously there have been some tuning issues with the larger Saitos, 150 & 180, as well as mufflers vibrating loose in order for me to return so many but they have been great at backing up their product.

I don't know what your issue is and that's important to you but for you and Cod to say this is routine is unfair to Saito.

This is not intended to criticize you guys. I just want to show that it is not always the case.

Thanks.

TomTreese, I know what you mean, I have gotten into these debates with die hard Saito people before and they absolutely refuse to believe anything can be wrong with Saitos, but it is what it is. It was a brand new Saito 100 and they are known to have problems with the muffler breaking off at the manifold, but when this happens, it breaks the casing and basically you need a rebuilt Saito. The Saito 100 had a 3 year warranty and they only fixed it twice and said they would not fix it again. I checked around the field and found people having the same experience with it breaking off at the engine. My main problem with this is that they did not honor the 3 year warranty, so I went to OS and have never had a problem at all. I swapped out my Saito 100 for an OS 91FS and it is still running in a 60 size ultra stick that is used in harsh conditions, it starts without failure every time and doesn't have parts flying off of it and breaking the engine. I did have an exhaust manifold break on one of my OS 91FS after a lot of hard flying, but it broke on the manifold pipe and I bought another one for $15, slapped it on there and never had a problem again vs. the Saito that needs to be completely rebuilt everytime this happens. I refuse to pay to rebuild the Saito 100 to just have it happen again. It is like pouring money down the drain. BTW, I was a die-hard Saito lover and was on the other side of the debate staunchly defending Saito until I had these issues, did some research and basically had Horizon, which services the Saitos, refuse to work on it again...that convinced me to switch to OS for dependability.

Chuck, I can understand your position and frustration. I just purchased an OS 91 FS for my Top-Flite AT-6. Sound great on the test stand. I hope the muffler stays in place???? It did vibrate loose on the test stand.
Do you use any special process to keep your's on??
I decided to go with the OS because you van get better deals and service from Tower.
I have not had a problem with Saito service but obviously I have had some problems with the engines. I've had to send them back 8 times[]

On my Dave Patrick Ultimate, first with a 150 and now a 180, I have had mufflers coming loose constantly. I've wrapped the threads with plumbers tape and used red Loctite without success.
The 180 is back for the second time,right now, because the manifold stripped the threads in the head. They replaced it the first time but it's been there 2 weeks and I haven't heard anything this time. I'm probably looking at having to pay for a new head[:@].

There is a definite vibration/muffler problem with the larger engines but they won't admitt it.
When I get it back this time I'm going to use a Slimline Pitts muffler. This is secured in two places and will not unscrew itself. I tried it before I sent it back this time but the threads were so torn up from their muffler it was leaking around the head connection.

I'm getting frustrated with the engines. It seems after about 30 hours they are difficult to tune. Two to three clicks of high speed needle goes from too lean to too rich. That's why I have sent so many back. They always say it's the bearings???
I run them dry and use 4 cc of after run & air tool oil after each flight. I'm not as happy with the 150 & 180 as I am with the 72, 100 & 125 ( which is their best engine) and the OS sounds better.

Put Our Warbirds Over Williamsburg IV on your calendar for June 6, 2009.

Thanks Tom
Nice weather we're having???

Yes, something strange with Saito and they told me everything was because of bearings also, rusted bearings etc, even thought I used after run oil, etc...just like they said to do. The Saito 100 was more powerful than the O.S. 91FS in my Ultra Stick, but I went for the reliability of the O.S..

I just started putting my first Venus II together, just getting the wrinkles out of the wings and stuff, I'm really looking forward to flying it.

Warbirds over Williamsburg sounds good, TRC has a lot of warbird guys. Yeah, last weekend was really bad, this weekend is suppose to be nice.

Also, try the red high heat RTV stuff with your OS. I even had a regular muffler on my YS110 once and after a few flights(this is the included YS Muffler) it started vibrating lose and lost screws, etc. I have a pitts muffler on that engine and it works much better. I have had to re-tighten the OS after a few flights then it seems to go forever. I did break one of the exhaust manifolds on an OS 91FS on my stick after about 1.5 years of hard flying and I just bought another one and slapped it on, it did no damage to the engine at all.

Chuck, I have some of RTV. So I'll try it. I am Balancing The AT-6 today. A bit chilly in the garage.[&:]

I just got the Saito 180 back. They said the rear bearing was running rough and was spinning in the crankcase. They said this is where the vibration was coming from and replaced the bearings, crankcase and cylinderhead under waranty... I know you didn't want to hear that...For some reason they have been good to me??? May be because I have 6 Saitos???? We'll see how this all works out.

On the Venus. I gotten into the habit of using pivot point hinges on all my 90 and 120 size planes. I have had CA hinges fail on my Ultimate, Yak and Edge. In all cases the rudder hinges fails first. Although the Venus will never have the throws and stress on the hinges as the 3D planes I installed them anyway. They are stronger and allow a tighter seam and I think easier to install.

I have the Saito 150 on the Venus and there is plenty of power with the 16X8 APC prop. I have had no muffler problems on the Venus??

You're goig to love your Venus. I like to fly pattern and this baby really tracks well.

Enjoy, Tom

Tom,

I am curios when you sent your Saito’s back for repair? When I developed bad bearings after 4 gallons of fuel (2 years ago), they told me they never guarantee the bearings. I waited a few days and called again. Got a different person and they said the same thing. They never warrant their bearings. Have they changed their policy or are they inconsistent? I will never forget the feeling of being told my model engine’s bearings were not covered after 4 gallons of fuel regardless of the reason when it cost more than my lawn mower. I gave then ample opportunity to stand behind this engine. Some have good report of Saito service, but many do not. Can we trust them or can we not? On the contrary I’ve heard nothing but good about OS support. I feel they have earned our trust. Has Saito? For me the answer is no. I hope one day I can feel different.

Cod

Tom reference not at all, I'm glad they fixed it for you, that's the way it should be...glad to hear it

Codfish,
I have just packed them up and included a copy of the purchase and a detailed letter about the problem. When I have had muffler problems I also include photos of the problem. As I said, all eight times they have replaced the bearings. Twice they have replaced the cylinder head when their muffler manifold stripped the threads. This time they also replaced the crankcase.
I guess I'm just lucky or the documentation helps?????

I now have an OS 91 FS on the AT-6. We'll see how that works. I do like the sound. We have a number of guys here with older OS 4-strokes and they always had tuning problems, numerous dead-sticks, andwasloose muffler issues. That's why I chose Saito 4 years ago. Now I understand the newer OS 4-strokes are better. So I decided to try one on the AT-6. The fact that it was a $100.00 less than the Saito with the Tower promotions made it a no brainer!

hmm...I haven't had to tune my 91FS, just did the usual break in which is 10 mins, set it up and it runs, two 91FS engines, accasionally you have to tweak the high end needle valve because of the weather changes. I really think this is brand preference. The guys at our field have had great luck with OS and swear by them. I believe it is a Ford vs. Chevy thing. Right now I have 2 OS 91 FS, 2 OS 120 AX, 1 OS 55AX and 1 OS 91 FX and they all run great, no problems at all.

Back to the Venus II and the star of this thread...I just noticed that my belly pan is broken, looks like everything else in the box is OK, but the belly pan showed up broken new in the box. I'll call tower and see what they say.

Check your Cowl for a color match. Mine did not match. One was True Red and the other was Missle Red. Don't remember now which was needed?? Tower sent a new one that almost matched. They said there was a mix-up in China.

I like my OS 46, and 55 2 strokes. Iv'e had 2 OS 50 AX that ate rear bearings. I sent the one back to OS twice in 6 months, about every 100 flights because it sounded like a coffee grinder. I think there was a problem with the OS 50's so they reppaced it with them 55's. In fact when I sent it back the second time the sent me a 55 instead of fixing it.
I still have an OS 50 on a MOJO that is on it's 3rd set of bearings. There easy to change and a set that costs about $10.00 at the Bearing place. I Use a lot of after run and it's lasted 200 flights?

When you get a good belly pan. Reinforce the forward cut-out with a thin sheet of balsa. Then when you pick up the wing from the front you won't run your finger through the Mono-Kote.[:@]
I repaired mine with some Trim-Sheet. it's heavier then Mono-Kote.

Tower said they will send me a new belly pan, I'll beef it up like you said.

That is a good idea. I beefed up the entire cowl with 1oz fibreglass cloth.

I paint all my cowls with a layer of alcohol thinned 30 min. epoxy. After I cut any holes in the cowl I reinforce around the inside of the holes with fiberglass tape and epoxy. Especially where the cown screws to the plane. Then use rubber backed washers on those screws to reduce vibration.

I also like to paint THE FIREWALL inside and out with 30 min epoxy to seal, strengthen and fuel proof it. I especially load up the seam inside around the firewall, sine the arf builders have been known to hot glue the firewall to the fuselage. I Also strengthn all the wood beteeen the firewall and the first bulkhead with epoxy for strength and fuelproofing. And make sure all the seams I can get to in the cockpit area are well glued and reinforced. Some thing you woild do if you built it as a kit. Especially around the landing gear bracket..

It does add a little weight to the Venus but it makes her solid!!

Tower still hasn't since the belly pan replacement for the broken one in the new ARF, so I guess I'll just fix the broken one.

Chuck, Stay on them as well as repair yours. If they said they would replace it they will. They just have to get one. On their website that item is "Order Pending" so it could be a while. So if the damage is minor I would fix it>>

The OS 91 II fs worked perfectly his weekend on the AT-6. Rann well and sounds perfect