johnpope60

I have a 17 cc and a 21 cc four stroke gas. Both of these engines idle great and run great at higher rpm. But at 1/4 throttle they both sputter. Any ideas ? Thanks

tailskid

My Feedback: (34)

I would love to see some pics of this plane......

FNQFLYER

Once I work out how to add photos etc I will start putting that stuff up on the posts but until then you'll have to create mind pictures. In the mean time attend a SAM comp near you you'll see all sorts of interesting engines and applications / adaptions of same not to mention the variety of airframes and characters operating them.

Hobbsy

My Feedback: (102)

FNQ, for picture loading,

Reply
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Select Done. The picture loader will store your chosen pictures so the next time you want to load the same picture or pictures just drag them to the Insert Box.

That looks and seems complicated but will be automatic after a couple of times.

cubfloater

My Feedback: (5)

Well finally tried the PB Blaster overnight and no luck. Sprayed in a little more and will wiggle on it tonight to see if any movement. If not I'll try soaking in fuel to see if that does it. Then I guess I'll pull out the wrenches...if I can find them. And I forgot to try the first simple idea which was pushing it down and releasing as Hobbsy suggested. I'll try that shortly. Hope that does it. Will update you on what works. Thanks

cubfloater

My Feedback: (5)

more PB Blaster, no luck, soaked in fuel still no luck. Guess I'll have to take apart. Will try tapping or wiggling a little more just in case before the dismantle.

bob62

My Feedback: (28)

If all has failed get a bigger hammer, works everytime

Hircflyer

I have a older 1.20 that needs to be overhauled. Can anybody recommend some who does a good job?

Hobbsy

My Feedback: (102)

http://bj-model-engines.com/home.html

This gent had a good reputation before he was a known quantity, he may be the repair center for RCV also.

bob62

My Feedback: (28)

I do my own, they run good.

Hobbsy

My Feedback: (102)

Yep, DIY guys rule, but are always glad to help out not so DIY guys.

FNQFLYER

Hope every one out there is still alive and kicking. On twins, on of the old guys at the club resurected a gold knight twin (capacity unknown) on the w/end. It was seized from miss use and not being used for a couple of years. Poured fuel down the plug holes and rocked the prop until it turned over. Oil on the valve stems and gentle tapping until they moved, replaced the old plugs and connected power and hit it with a starter. Result my old flying mate now needs a new shirt, the old one was blasted with a mixture of rust, carbon, old oil and fuel but the bast ran. Very noisy but nothing a set of new bearings won't fix. Now onto the next of quite a few Saitos in this collection.

Red Fish

Do you guys know anything about the reliability of the larger Saito gas engines. I know. Saito got off to a poor start with gas ,but don't know how they have progressed. Reviews are hard to find. I am looking at the 57cc twin gasser. Perfect for my project , but I don't was something unreliable.
Thanks
Henry

Hobbsy

My Feedback: (102)

Red, more Gas Saito guys will see this question over in the Gas Engines Forum. You'll get lots of responses there

w8ye

My Feedback: (16)

If you are going to run a gas Saito, you had best have a good knowledge of Saitos as well as small gas engines. The original Saito inductive pickup ignition wasn't that successful and the Saito branded 1/4-32 spark plug has been prone to foul and the insulator to have shorting problems. The present version ignition module is made by RCEXL with a Hall Effect pickup but it says Saito on it. The 1/4-32 boot is made for the Saito spark plug. The CM-6 boot is the same as RCEXL.

The carbs up through the FG-21 have very poor fuel draw so the tank must be mounted right against the firewall and on centerline with the carb.

To tune the carb on the test bench is just preliminary to adjusting the carb for effect while flying in the air (fly-adjust-fly again).

The Saito/Walbro barrel carb on the larger Saito engines is somewhat of a failure for there are no diaphragm kits available for it from Saito, Walbro, or after market and a couple years down the road when the metering valve diaphragm goes bad, you are stuck $96 and have to buy a whole new carb from Saito.

You must run a 20:1 gasoline-synthetic oil mix in these or risk loosing the big end of the connecting rod.

Rudolph Hart

Red plus one on barrys reply.I run 25 to 1 with klotz 200 synthetic,plugs run a light brown at factory settings.Don't feel overly inclined to change them as the engine pulls factory specs on the benchmark prop.Did i mention how good they sound when you throttle them up?

FNQFLYER

Old fart, have you tried that oil HHQ is marketing as Saito oil suitable for gas engines? I am about to get the Storch up and running (in the next month or 2 ) with an FG20 in it. All the Fg20's I have seen with the modified carby supplied by HHQ (from Saito) seem to run ok with minimal fuss. I also have an FG36 and those comments W8ye have me a bit bothered. I have read a lot about ignition failures (on both saito and os etc) but a lot of it can be put down to correct handling (particularly leaving the ignition switched on after engine shut down). Your thoughts please

Rudolph Hart

Hi fnq don't worry to much about the way saito have there fourstroke gas engines set up now,tho they jumped in at the deep end first,i wonder at how long they benched or flew the engines before they offered them for sale.I think the problem with the fg30 and 36 initially was that the ignition system barry talked about(plus every single outsourced damn carby)was really average.They still sound awesome and i think we should open up this forum and include them also.They may not have that special bark that nitro saitos have,so what,we all like flying them.

Hobbsy

My Feedback: (102)

Pete, I think that Barry and Jim would concur that talking Gas Saitos here is just fine, after all a Saito is a Saito is a Saito. I only recommended the Gas Forum to Red because there is lot of info there already. Not all of it good or accurate but there none the less. Jim straightens it out where needed.

hsukaria

I need help deciding between a Saito FA-82 and FA-91. I have a 60-size sport plane, a Phoenix Extra 330S that has been using a 74 and a 90 2-stroke glow engines. But now I would like to switch it to 4-stroke. The plane weighs about 7.5 lbs. I would like to get unilimited vertical so that I can do some 3D flying also. Would the 82 be enough, or should I get a 91? I already have an FA-82 on a 7.5 lbs Great Planes UCD46 and it gives unlimited performance. Weight or space are not an issue with the Extra 60.

Red Fish

Thanks. I will try that.

cubfloater

My Feedback: (5)

how do you know if your bearings are worn out. I thought one I had needed it but then I got another and it may but the first ones seems smooth and quiet compared to it and others I have. Would it be loose or just noisy? Thanks

Rudolph Hart

Huk if you were happy with the 90 two stroke you should probably go for the 125 saito even if that means putting the flight pack in the tail.

Rudolph Hart

Cub position yourself in front of the engine then gently put a hand on each prop tip and rock the prop tips back and forth (towards and away from you)if you feel ANY movement the bearings are toast.

Hobbsy

My Feedback: (102)

Pete, I'm not so pessimistic about a fourstrokes power, paper hp on a fourstroke doesn't look so good, flying hp looks about the same size for size. But that's just me. Between the .82 and the .91, the .82 turns a 14x6 close to what the .91 does but weighs less. I call it a toss up.