RE: cam gear timing?
Jeff, Good news. Now that you have it runing, got over the needles one, or two more times. Use this sequence. 1. Lean the high speed at full throttle for max RPM, the go rich enough to drop around 400 rpm. 2. Set the throttle to the lowest setting you can and still keep the engine running. At this point, lean the idle for maximum RPM. Don't change the throttle. 3. Now go back and adjust the high speed again. IE repeat #1 4. Repeate #2, the idle should be slower this time 5. Now run the engine to full throttl for a few seconds then go to full idle. After about 15 seconds or so, jam full throttle. If the engine dies when you do this, the idle mix is a little too lean. If it slowly gains RPM or gurgles and bubbles, the idle is to rich. Adjust the idle in 1/16th turns in the approiate direction The engine should jump from a full idle to max RPM in in less than one second. 6. repeat the above 5 steps one more time. A warmed up and properally adjusted engine should just jump from dead idle to full throttle, every time. Full or near empty tank. 7. Don't touch the needles again until there is a sight drop in throttle response. IE, if it ain't broke don't fix it. All the four strokes I've had my hands on work well with these instructions. The exception is the O.S 1.20 Pumpers. They are slow to spool up, but other than that, great running engines. Don
Posted on: 5/16/2013 7:06 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11513768

RE: cam gear timing?
Jeff, just pull the glow plug and use a wood match stem, or wood toothpick through the glow plug hole and feel when the piston hits TDC. Then look at the cam timing, As long as the dot in on the line in the photo from W8YE it is right, IE either up or down, but on that line when the piston is on top, the engine is timed correctly. The gear on the crank has few enough teeth that you will not have trouble getting the right tooth as long as the piston feels like it is right. One more thing, the sprial on the gear prevents you from lining up the dot and pushing the cam in, The dot is in place when the cam is fully in the fixed bearing. But being one tooth off is really obvious, so after you check it and find it off, just pull the cam out enough to disengage and turn it in the right drdiction until the next toot egages and you are home. Don
Posted on: 5/16/2013 1:23 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11513454

RE: OS 70 surpass bearing replacement
I thought about the hidden head screw later. I'm getting rusty, it been a couple years since I had an O.S. engine down. I had forgoten about the sleeve and the wrist pin issues. Like you, I "lost" one of the teflon pads on a rebuild. I happened to have a piece of teflon rod, so I made another pad. When I went to assemble the engine, I discovered that there was only one pad used as there was either a C ring or lip in the piston that prevented the pin moving out the other side. I don't remember if it was an O.S or Magnum engine, they are nearly identical in design. In any case, I really hadn't lost the pad. I was just used to seeing two of them. Lots of other good tips there MC. Don
Posted on: 5/15/2013 11:14 AM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11512369

RE: What is the
They built a house close to me a couple years back and the walls were like your Jo-Ann lit ply. a 3 1/2 inch slab of styrofoam sandwitched with the exterior partical board. Not a 2x4 to be seen save the cap that they needed to nail rafters to. I couldn't believe it. Not susprised at what you might find in a kit now. Don
Posted on: 8/27/2012 5:57 PM by Author "Campgems" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11208319

RE: Old OS 120FS-P Surpass II
The pump is a gear pump. I had problems with mine and it turned out that the seal on the input shaft was leaking untill it warmed up, There was so much blow by on the seal that the crank vent was pumping fuel up to the manifold,and even with the needle closed, there was more than enough fuel gettting by the carb to keep the engine running but as soon as it warmed up the seal worked and the engine would die. I used two T's in the fuel lines, one on the tank return and one on the carb line, then connected them with a smaller piece of tubing. This set up a bypass that redued the fuel pressure at the diaphragm. I've only flow the plane a couple times after this but it worked very well. Don
Posted on: 8/24/2012 10:31 AM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11204573

RE: 4Star60 Clip Wing & Reduce Dihedral Mods
You can remove the epoxy. I use a hot knife, a soldering iron but with an Xacto blade holder. Xacto makes some chisel point knives. They work fairly well in removing the slopped over epoxy. They are not fast though. A soldering iron with a chisel point to get things heated then the hot knife for the actuall removal works. I hate to say this, but apperantly in one of my later system crashes, I lost my 4*60 and some other CAD work I had done. Really ticked me off. It was probably when I migrated to Win7 late last year. The extra braces probably isn't a bad idea. I just built a new box to slide the new brace into, and lots of epoxy. On the final flight of that one, I went in nose first and really destroyed the plane. The wings were both badly damaged, but the center section was intact. Don
Posted on: 8/15/2012 3:09 PM by Author "Campgems" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11194831

RE: 4Star60 Clip Wing & Reduce Dihedral Mods
Seamus, I had exactly the same issue, only mine was from trying to salvage a partial built wing. Here is what I did.. Everything you did so far with one exception. I left the top and bottom sheeting intact to the orginal glue line. I cut two new root ribs and fit them to the saved sheeting. I cut a new dihedral joiner and fit it to the back side of the orginal one. The reason for keeping the top and bottom sheeting intact was the two dowls that hold the wing to the front former. You have to mataiin the spacing on them or you are faced with enlongaing the holes in the former to accomidat the new spacing for them. A proper center rib fit, to the spars and the sheeting is important as it provides the structural strength to hold the wing together. I cut mine from 1/8 balsa to allow for the sanding and new angle. Fit the new ribs into the wing halves. Then sand them to the new dihedral angle. space them apart so the dowels fit the former, then sand and fit a thin balsa sheet between the root ribs so the dowls fit, Make sure your new dihedral brace fits well then epoxy everything together, keeping the angle and the Te and LE aligned. Glass the new joint and cover. If you need a template for the root ribs, I may just have one you can print out. You will need legal length paper though. Let me know and I'll find it. Don
Posted on: 8/14/2012 9:08 PM by Author "Campgems" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11193936

RE: OS 120 glow plug wrench
A 1/4" drive 5/6" socket will fit if it is one of the thin wall designs. A 5/16 nut driver is another choice.. You may not be able to get the socket drive all the way into the socket but you will have enough bite to lossen and tignten the glow plug. Some of the nut drivers, IE the onew with the hex shafts may not be deep enough either, The ones with a screwdriver handle generally will. Or, if you have or have a friend with a lathe. bevel the top of the head screw. I did the later on my 1.20. If you screw two nuts on the screw, you can grasp them in a drill chuck and can probably filre off enough ot the head to clear the wrenches without scrwing up the threads on the screw.. Don
Posted on: 7/31/2012 10:08 AM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11175975

RE: Landing gear bracing
The stouter you make the landing gear, the more likely you are to rip out the landing gear mounting from the fuselage on a hard landing. Don
Posted on: 7/28/2012 2:20 PM by Author "Campgems" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11172443

RE: Magnum Carb on OS 70 FS-1
A remote needle valve should work OK. I think. However, did the OS carb have the idle and high speed needles on the same side? If so a remote may not work. You should reset both the high and low speed valves to factory stock settings then try again. Your description of things are exactly like my Mag 70 was after I first got it running and the "experts" at the field helped me adjust it. Resetting both valves to stock setting and then go from there solved my trouble. Don't touch the idle until you have the high speed set as you will screw up the balance between the two. Also, did you put a gasked on the intake to head? OS doesn't use one, but Magnum needs one. Try a tank of Omega 15% 28% seem way high. You may wan't to check wiht Global and see if they have had any problems with the carbs. Don
Posted on: 7/27/2012 4:38 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11171668

RE: Magnum Carb on OS 70 FS-1
The carb will be just fine. What it sounds like is that you have the idle and high speed way out of sync. My Magnum 70fs was the most contankerioius engine straight out of the box. It started and ran sort of with the factory carb settings, but as soon as I started tuning, things fell apart. It isn't an O.S carb and it doesn't tune the sam way The O.S carb idle mix has you screw it into a stop then back out X turns for the start point. The Magnum carb will let you screw in the idle mix to the point it falls out of the threads. You have to start from fully unsrewed to the stop, then in x turns. Pull up the Magnum 70 manual and set your carb to the starting points suggested and then tune from there. It will work out just fine. Sorry, it's been about 5 years since I went down this path and I don't remember the exact settings. Seems that the idle was 2 1/2 turns in from flush with the throttle arm. and the high was 2 1/2 turns out from a screw in to stop. Don
Posted on: 7/26/2012 8:26 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11170771

RE: thinning out kits, which one would you sell?
Take a peak at our club web site, www.Sloflyers.com. The Jenny on the home page was built from an Ikon N'west" kit by one of our ex Club Presidents. It is a very impressive build. Just to nudge you to keeping the Jenny kit. Don
Posted on: 7/26/2012 8:10 PM by Author "Campgems" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11170755

RE: Biplane ID ...
My first guess is that it is a Great Planes Super Aeromaster. The overall design is very similar, but a couple things are different. The ailerons on your plane are near full length while the Aeromaster had just short ones at the wing tips, on mine nly on the lower wing as yours is.. The Aeromaster had three wing configurtions and one is as shown in your photos. The cabane looks the same as well as the cockpit. The landing gear isn't stock, but mine isn't either. The Stock cowl was a built up balsa cowl. Mine has a Fiberglass Specialities Waco version of the cowl. My wing span is about 50", measured from the floor with the wing on a rack high on the celling. I'm not sure that is all that accurate. The Aeromaster needed a 90 four stroke at a minimun and up to a 1.20 if you could squeeze one onto the firewall. I couldn't. I've yet to fly mine. It comes in at around 9.5 lbs. Don
Posted on: 7/26/2012 7:59 PM by Author "Campgems" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11170747

RE: IS THIS ENGINE TOAST?
You are welcome. I just noticed something in the photo, the location of the crank vent. I guess it is the first one I've seen that goes through the mounting lug. Was this an add on or the stock location? Make sure the lifters move smoothly, there should be enough of the two bores left that they wont be a problem, but check just in case. Don
Posted on: 7/13/2012 3:55 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11154235

RE: IS THIS ENGINE TOAST?
I was rebuilding an O.S 1.20 for a friend and as I was cleaning up after the boil out, it looked just like your photo. I felt awful and I searched all over the shop to for the piece I broke loose, but couldn't find it. Time to fess up, so I did. OH, I forgot to tell you about that, it was like that when I got the engine, he said. I put it back together and tested it out and it ran just fine. I think he is still flying that engine. Make sure there are no flakes to pop off, a dental probe poked around the break willl tell if everything is OK. Put it back together and enjoy it. Don
Posted on: 7/13/2012 3:41 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11154220

RE: wing servo wire tubes?
I ran across this last nigh when I was looking for some small square tubes to hold my taps. http://www.mcmaster.com/#shipping-tubes/=iago5h Look down the page a bit at the cut to length tubes. They have the light weight polyethylene tubes 48" long in sizes from 1/4" up to 2 2/12" D . The price isn't bad either. Don
Posted on: 7/6/2012 10:46 AM by Author "Campgems" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=11145435

RE: Taylorcraft crash
[quote]ORIGINAL: flyallday You paid someone elese to pack a totaled plane into boxes? Everything is clear now. Harry [/quote] Best laugh I've had in a week Don
Posted on: 7/5/2012 9:04 PM by Author "Campgems" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11144802

RE: Taylorcraft crash
<![if gte mso 9]> <![endif]><![if gte mso 9]> <![endif]><![if gte mso 10]><![endif]> ""Well nylon All the bolts you need for model building! bolt srtipped and caused wing to seperate a bit from fusalage"" No, the bolt didn't strip, you cross threaded it and cut the threads. You can not pull a 1/4-20 nylon bolt out of a nut with more than three turns into it, it will pull the bolt in half. Cross threading, IE trying to start the bolt at an angle and then continuing to "drive it home", will. A nylon bolt that will screw into a nut with your fingers is gong to hold, even with a loose fit on the threads. Finger tighten, then go maybe a half or 3/4 turn at the most and you are good. Nylon stretches like crazy, so if you keep tightening it, it approaches the tensile strength of the bolt, and a minor bump at this point is enough to break the bolt. If you finger tighten and then give a snug. you have all of the stretch to take up shock, but still hold. If you tighten it down like a metal screw, it will pop at the slightest stress. In your case, tough, this didn't happen as an over stressed nylon bolt will leave a nub in the nut. Your threads were damaged when you took off. There is no other explanation for a bolt to "strip". Perhaps a couple hundred screw and unscrews may wear the threads enough, but even that is unlikely after just a few flights. Don
Posted on: 7/5/2012 8:49 PM by Author "Campgems" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11144786

RE: wing servo wire tubes?
It seems that most servos in any plane over a 60" span need and extention. I've often though of hard wiring the fuselage and wings. and the cutting the servo lead to about 2", so the extention plug was right at the servo.. A change of a servo would be no more dificult than removing it or the hatch over it and unpluggin it right at the servo. You are going to have at least one extention anyway, so you wouldn't have any extra connections to worry about.. Don
Posted on: 7/5/2012 10:51 AM by Author "Campgems" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=11144046

RE: wing servo wire tubes?
I aquired a large vintage pattern plane a few years back. Sure wish the guy that built it (Unknown and scratch built) had read this thread. He drilled holes in the ribs just slightly bigger than the servo wire, wrapped the wire with masking tape at each rib and then use a generous amount of glue to hold the masking tape to the rib. Of course, I had to replace the aileron servos. I've got four plugged holes in the balsa covering.and new covering on the bottom of the wing. And guess what, I used the washer and string got get the new wires in place. There was a set of holes in the ribs he could have used. Don
Posted on: 7/4/2012 9:51 PM by Author "Campgems" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=11143426

RE: 4 Stroke Prop Nut
That will work. However, some of the Magnum cranks need the thickness of the spinner back plate for the prop washer/nut/jam to really grab the prop IF it is a low pitched prop. I've even had isues with a 6 pitch prop. The 4 pitch is gong to be a problem for sure. You could use the center hub of an aluminum spinner back plate for a spacer though. The only other issue is betting a starter cond to fit over the nut combo. Some cups when reversed work just fine, Some don't. On one ocassion, I ended up with the engine turning over at a fast idle wth the cone still stuck on the nut. It pulled out of the cup on the starter. If you use a chicken stick for starting. this problem goes away though. Don.
Posted on: 6/24/2012 12:38 PM by Author "Campgems" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11129970

RE: How to handle the guys with flawed plans?
Jester, it's really hard to teach someone who knows everything already, even harder if they don't but think they do.. Good instructors are hard to find, so save yourself for someone who wants to learrn and is willing to take some instruction and appriciates your help. Help those you can and discard those you can't. Not every one is cut out for this hobby. Don.
Posted on: 6/20/2012 10:16 PM by Author "Campgems" in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11126119

RE: OS 160 Twin
Have you thought about going to ignition? I had a FT300 for a short time, got it from one of our club members. He had put a manual advance ignition on it and when he got things right with the advance linkage, that engine would pop tick over at an astounding slow speed. This was using glow fuel. Steady as a rock also. The weight gain would be just a few grams more than an on board glow system. Don
Posted on: 5/24/2012 9:59 AM by Author "Campgems" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=11093129

RE: DA 250 Twin Super Charged Four Stroke
Sure wish that photo was of the back seat of my car. Don
Posted on: 5/18/2012 7:51 PM by Author "Campgems" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11086329

RE: question about my 4 star60
The DX8 guy will most likely be able to help A Futaba guy (Me) won't as the programing steps are quite different although the end results are the same. Good luck with it and let us kow how It's working out. Just a thought, you might ask on the RC Radios forum. This isn't unique to the 4*60 so you should get a ton of hits over there. Good luck Don
Posted on: 5/16/2012 6:32 PM by Author "Campgems" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11083721

RE: question about my 4 star60
Todd, it would be a good thing to get an experienced guy that is familiar with your TX and have them show you how to setup the Expo. A lot of the older guys told me that " you need to learn to fly without it" Thats a pile of B.S. You got it, use it. If one of your experienced guys tells you that, thank them and go find someone else. The reason though that I suggest someone that is fimilar with your radio is that different brand radios define positive and negitive expo different. Your goal is to soften the movement around center, and harden it the more stick you give. Dual rates go hand in hand with expo. You want a high and low rate setup, each with its throw limits and expo. Early flights should be done on the low rate, large expo settings untill you get the feel of the plane, then you can start dialing in more throws and firmer sticks. By the way, the 4*60 is a great flying plane. I've had two of them. I suggest that you NOT use the steel landing gear screws though. Qty 4 of #10 nylon screws or three 1/4" nylon screws will save you some repair time after your early landings. The landing gear mounting plate is not very stout, so screws that shear off before ripping the mount out is a good idea. If you ran off the runway at our field, and snagged a wheel in a goppher hole, the nylon scrws would save the day. Don
Posted on: 5/16/2012 3:43 PM by Author "Campgems" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11083495

RE: Saito 91 intake valve leaking will not run.
Guys, it looks like I learned something new today. Now to find out how. Don
Posted on: 5/15/2012 11:12 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11082573

RE: Saito 91 intake valve leaking will not run.
<![if gte mso 9]> Normal 0 false false false MicrosoftInternetExplorer4 <![endif]><![if gte mso 9]> <![endif]><![if gte mso 10]><![endif]> Guys, this is the day of CNC machining with tolerances better than 0.0001" . No secondary operations are needed. Cut it exactly right and install it. No lapping, so pilot reamers. On removing the old guide. You could pull it out. The best way would be to use a socket head cap screw that just fit into the bore and an with washer to fit tightly to the stem and just shy of the OD of the bronze guide. Put a capped tube with an ID of just over the OD of the insert on the top end, flat washer and a nut and start turning. Or another way would be to thread the ID of the bronze, using a coarse thread, and then just use the cup on top. with a screw from the top. With either method though, I would put the puller in place and snug it down then put the whole shebang in teh kiln at 350F for a half hour, pull it out and start screwing. The guide should pull right out. On installing the new guide, it looks as if, at least on my 150, that Saito machined a flat on the head /seat. You would need an anvil with a really true, flat surface to support the head for pushing the new guide in place. This would be slightly larger diameter than the OD of the valve face. Again, I would heat the head, but this time freeze guide and you could probably hand slip it into place. The big challenge is getting it started exactly straight. Machining new guides wouldn't be much of a problem with the exception of the deep grove that the spring sets in. I expect that the blanks are cast and finished to size. About the only I can think to cut that grove would be to use the rotary table on the mill and mill the grove. The bottom line is that it would take more time to make the fixtures to do all this than to make the guides. It can be done, but as Freakingfast said “but at what cost $$$ or friendship” Last, are you guys sure the valve seat is chrome plated? I wasn’t aware you could plate aluminum. Don
Posted on: 5/15/2012 4:23 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11082143

RE: OS .60 RF fuel pump quit. Now what?
I can't tell from the parts listing for the engine, but it looks like it is a diaphragm pump. Not from the outside, but the crank doesn't show a long throuw to engage the input disk on a mechanical pump. So, pull the back plate and if there is just a hole to the pump, it is a diaphragm pump and the Perry pump will likely work with an adaptor into this hole, Or you may be able to repair the pump. If you can, pull the back plate and post a photo or three. I've had good luck repairing both the 120 Surpall II and Surpass III pumps, The II is a gear pump, and the III is a diaphragm pump. Some clean phots should tell whether the pump can be repaired or not. Don
Posted on: 5/14/2012 8:52 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11081036

RE: Saito 91 intake valve leaking will not run.
John, 100% agreement. I'll add this. The Carb throttle barrel at idle will block almost all back pressure from an open intake valve on compression. I say almost all because the carb is usually set up so it will not fully close at idle, or the engine will quit. If the barrel is slightly open to the intake manifold, it is open a like amount to atmosphere so there would be little pressure built up on the spray bar, no where near the amount needed though a properly adjusted needle valve to provide enough volume of air to "be like blowing a straw in a glass of water" . In fact, the carb would draw fuel with the flow of air from manifold to mouth the same as it would from mouth to manifold. If there were a choke flapper covering the mouth of the carb, then some pressure could build around the spray bar. The OP is missing an observation of the problem that would lead to a fix. If the crankcase vent were connected to the tank vent/pressure port, there would be a significant amount of air pushed into the tank on the down stroke, but not through the pickup line. We need more information. Don
Posted on: 5/10/2012 10:41 PM by Author "Campgems" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11076590