w8ye

My Feedback: (16)

Did you get your valve clearance set correctly.

If the intake valve is leaking on the compression stroke it can push fuel back to the tank.

BAlbertsman

I think so but i will definatly check that again.

Should I be worried about not having a ton of compression at this point, or does the engine build up compression as it is run a couple of times?

thanks again,
bernie

w8ye

My Feedback: (16)

Most of my Saito have had decent compression after a new ring/cylinder situation.

You may want to check your cam timing.

Use the valve overlap method. Take the valve covers off. Turn the crankshaft to where the piston is at top dead center but not on the compression stroke. Both valves should be open the same amount with one closing and the other opening.

RPMcK

My Feedback: (1)

Any chance your intake valve is not closing completely on the compression stroke?

BAlbertsman

RPMcK, I double check along with valve clearance when I get home.

It kind of brings up another question I did nothing but drop the new valves in there respective spots in the cylinder head and put the new spring and keeper on. Was there something else I was supposed to do to the new valve or head to seat them properly?

WMB

My Feedback: (1)

isn't this normal?
I noticed my Saito 45 doing this the other day. Could have sworn my 82 does it also. Both run great.
Once I hear the fuel at the carb they are usually ready to fire up.
MikeB

RPMcK

My Feedback: (1)

I would think if the valves and head are both new they would probably seat properly without out doing anything to them other than adjust the valve to rockerarm clearance.

w8ye

My Feedback: (16)

You have to adjust the valve-rocker arm clearance at .002" - .004" anytime you have the engine apart

Michaelh

My Feedback: (4)

Wood props smush when you tighten them making it hard to get off, never really noticed this on the composites.

I typically set the double jam nut toward the end of the crank,hold it with a wrench and slowly turn the prop off.

But sounds like you might be stuck more then I get stuck[X(]

swixtt

thanks... i'll give that a go too!

Yaniel

how do you guys fuel your planes? i have a 3 line setup to a fuel dot. and fuel dot line runs into the tank and points up next to the vent line (i know i should have used a clunk to defuel too but i didnt think about it and its too late now [&o] ) but while fueling theres always fuel flowing out of the muffler and into the carb too. what have i dont wrong?

linkadrip

Your going to have to take that tank apart and redo the fuel lines into the tank. On the ones were I have a three line setup to a Fuel Dot the fueling and defueling line points toward the bottom of the tank. the vent line that runs to the Muffler is pointed toward the top of the tank and the regular line for the engine is of course just on a clunk running to the rear of the tank but has enough room to freely move around anywere in the tank. dont want the fuel draw line to get stuck on the back of the tank in inverted or other Manuvers.

I recently had this problem with the pitts i'm putting together. I tried to fill it up upside down and the fuel was pushed out the muffler becasue the vent line was submerjed in the fuel just pushig it out the muffler it doesnt do this if its fill right side up. but it's only a 2 line tank i stopped doing three lines. I just put my fueler in the main line and it fill throught the clunk and defuel through the clunk now, and seems to work good that way.

your sounds mysterious. with the fueling line from the fuel dot toward the top it won't defuel unless you invert the plane and get the tube submerjed in the remainig fuel in the tank but shouldnt have a problem fueling. Only time fuel usually gets pushed out the muffler is when that line is submerjed in the fuel and the air is pushing the fuel from behind.

really not to complicated not like the jets are. But its never to late unles you epoxied the tank into the plane. You should always have the tank so it will be removable for maintaing it. Fuel ine were and get pinholes ect from time to time and have to be replaced ect.

Dont know if what i said makes any sence i'm sure there are others that have a better or different way of explaining things better then i would. Guess you just have to picture it.

My crued drawing

A good thread to read through.

http://www.rcuniverse.com/forum/m_63...tm.htm#6378846
A pictur from that thread that looks better.

Yaniel

my setup is basically just like your drawing, except the fill line runs up instead of down, i had a brain lapse and didnt think about de-fueling. the vent is at the very top of the tank so i dont understand why i constantly see fuel running through the vent line while fueling even though the tank isnt filled anywhere near the top, and i always have fuel go into the carb even though i hear its not supposed to happen with 3rd line systems. if it comes down to it, i can pull the tank out but i'd like to know what to look for before i do.

linkadrip

I'd just pull it and go through it and do it right anyway. Shouldnt take that long to do. and that you may find the issue in the process of doing it too.

Just my 2 Cents. I would if i had that problem I sometimes pull my tank 3 or 4 times in the process of building a plane because of one problem or another. I have to pull my prop off and cowiling and the music wire out of the High speed needle. Just to put my fuel Dot in the cowl on my pitts. But it's better to know its rights. then to wonder why its not working correctly takae it appart and find out. I hjave pulled the tank on this little Biplane at least 5 time already. had to keep positioning the fuel tube inthe tank farther back so it wouldnt be pinched between the engine and carb very tight fit but cant have any kinks in the lines.

I'm a mechanic too i know not everyone likes to take things apart after there together. But sometime its neccessary to get it Correct and to find the problem.

swixtt

i sort of did the same thing when i was building an at502. too late to get back in there... i just capped the fueler line(hasn't been used since) and then used a Dubro Fuel dot connected into the clunk line and then into the carb. left the vent to the exhaust as per normal.

stallwart

I also use linkadrip's tank setup on almost every plane. I also use the Hangar 9 fuel dots, since they agree with me (idiot proof) and don't need a special docking connector.

With a length of silicone fuel line directed to the the bottom or in a bottom corner of a rectangular tank, I can draw every drop of fuel out when defueling through my fueling line. I've tried double clunking, but find it to double the chances of having the clunk come loose.

Be careful in choosing silicone to use in the tank. I've had some crystallize and disintegrate in a year's time. What's best to use in the tank?

linkadrip

Havent had that problem yet. Gas planes Use neoprene gas tubing silicon will melt or Disenegrate. But for regular Nitro fuels Silicon seems to work fine in the tank. Some ARFS come with a clear plastic line for the main clunk line. And its not silicone looks to be Vinyl UPC type line or at least thats what it says on it. My pitts came with one in the tank for the clunk so i used it.

The Saito Engines use such a high lubricating type of fuel i wouldnt think silicone would crystallize and disintegrate but in a years time if it sits in the fuel it may happen. but if you take all the fuel out of the tank i wouldnt think there would be anything to attack the Silicone.

Well just my 2 cents

orcrest

I have Saito 80 and I was wondering if anyone has had any luck returning the oil from the breather nipple back into the intake manifold like the magnum engines do? Would it affect the running of the engine either from oil being injected back through the carby or from the intake vacuum sucking oil out of the crankcase? Where would be a good place to tap the intake manifold? Also is it normal for oil to leak out through the crank case screw that locks in the cam gear shaft?

Cheers

Da Orc

Hobbsy

My Feedback: (102)

Orc, I have an older .80 from 1991 and it has always done that, its the only one that does. I never considered it a problem though.

Capt Lou

Yaniel:

If you can get your hands on a copy of the June, 2007 "Fly RC Magazine", there is an excellent article on page 32 that discusses fuel systems to optimize a plane's performance. It details the various methods of tank fuel line configurations. I saved the article so if you contact me at [email protected] I'll send you a copy.

stallwart

That's what I would have figured, too. the tube I'm referring to might have been some of the reddish colored Prather tubing, since I've bought that in the past. Anyway, half the tubing broke free with the clunk on it, engine conked, but deadstick landing was no problem. When I removed the tank, the tubing was in numerous little sections.

I usually use the smaller diameter clear tubing that comes with ARFs because it is so flexible.

blw

My Feedback: (3)

Tubing doesn't last forever. Sometimes, less than a year.

crashnburnrc

My Feedback: (1)

Hi everyone! I have a Saito 90ts that I plan on putting in a Top Flite 40 scale piper cub kit. Will this be to much or what? Way cool looking with the cylinders sticking out the sides.
I also would like to join the club....Please.[8D]

I also have a 80 gk. Plan on putting it in a Sig Hog bipe With Snoopy at the controls.
I have been trying to read all the posts on this club but have only made it to page 23. Got tired of all the reading and skipped to the end.[X(]

w8ye

My Feedback: (16)

The 90TS will be OK in the Cub but actually it has more power than the Cub needs. The engine is pretty much the same external size as the 60T so the 90TS will be fine.

The 80 will be good in the Kadet Sr.

RCBOATMANIAC

[8D] Well I finally broke down and I got my hands on a Saito 180, it is definetly a hand full of an engine, I'll be anxious to see how it will run in my 1/5 scale Waco. So I quess now I can be a part of Club Saito, but I do have a question since I bought it used off of Ebay and I don't have any paper work for the engine I have been trying to find out what size thread is for the crankshaft so I can get a different prop nut, I measured it with my calipers and I came up with about 8mm or 5/16 if any body could give me the right size and thread pitch I'd appreciate it.