Glow Engines Discuss RC glow engines

Saito 100 needle problems

Reply
Old 10-20-2012, 04:29 PM
  #1
AdamPrime
Thread Starter
 
Join Date: Oct 2012
Location: carlisle, PA
Posts: 6
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Saito 100 needle problems

Hello I am new to 4-strokes and am having a bit of an issue with a Saito 100. I am using a Kelco custom exhaust on a Hangar 9 Spitfire with a blade 13x8 prop. I am having issues trying to get the engine tunned. The issue that I am having is the high speed needle valve doesn't seem to have an effect on rpm. It peeks out around 10,300 rpm. When I turn out the needle valve it richens up but the rpms dont seem to change. 1 full turn will cause a 100 rpm drop. As it is richened the exhaust gets smokey and sloppy so it seems it is running rich but the rpms don't seem to change. When I shut it down there is oil and resuide covering the plane as you would expect from a rich engine.I have tried different fuels 15% synthetic and castrol blend and 30% all synthetic. I verified no issues with fuel lines and the Carb has no obstructions. As all of my previous experience is with 2 strokes I don't know if I am doing something wrong. I just dont know how to tune it if propperly if the rpms dont change. Thanks Adam
AdamPrime is offline  
Reply With Quote
Old 10-20-2012, 04:51 PM
  #2
w8ye
Moderator
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,533
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Open up the low speed needle a little and try the high speed again
w8ye is offline  
Reply With Quote
Old 10-20-2012, 04:54 PM
  #3
blw
Moderator
 
blw's Avatar
 
Join Date: Mar 2004
Location: Opelika, AL
Posts: 9,260
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

It sounds like your low speed needle valve is too rich.
blw is offline  
Reply With Quote
Old 10-20-2012, 09:45 PM
  #4
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Is it possible that with that custom exhaust that you are not getting enough pressure to the tank somehow? I've had that happen and richening the HS needle didn't have much effect. Keep us posted, thanks,

Ernie Misner
Ernie Misner is offline  
Reply With Quote
Old 10-21-2012, 03:16 AM
  #5
Old Fart
 
Old Fart's Avatar
 
Join Date: Apr 2008
Location: Perth, AUSTRALIA
Posts: 3,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Adam i'd set your low speed needle back to factory settings and peak the hsn, i think w8ye is saying you are to lean on the LSN.The prop figures at peak sound really too.
Old Fart is offline  
Reply With Quote
Old 10-21-2012, 11:31 AM
  #6
blw
Moderator
 
blw's Avatar
 
Join Date: Mar 2004
Location: Opelika, AL
Posts: 9,260
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Well, that's embarrassing for sure. I meant too lean. Good grief.
blw is offline  
Reply With Quote
Old 10-21-2012, 05:55 PM
  #7
AdamPrime
Thread Starter
 
Join Date: Oct 2012
Location: carlisle, PA
Posts: 6
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

I took a look at the low speed needle and it was turned in substantially. I think more than 4 full turn out to get it back to factory settings. I had my flying clubs "Saito expert" help me set it up originally and that is where he set it. I think that the low speed needle combined with the custom exhaust could be the problem. It does have a pressure tap but the scale exhaust system has 6 outlets so I am sure that it gives less pressure to the tank then the stock muffler. I also think a contributing factor was the fuel lines used to have a siphoning effect. When I was breaking in the engine, I had to clamp off the fuel lines to keep the carb from filling with fuel when the engine wasn’t running. The siphoning mysteriously stopped and that was around the time I started having issues with the needle. I suppose the siphon effect was pushing more fuel in. Why the siphon stopped, I do not know. Adam

AdamPrime is offline  
Reply With Quote
Old 10-21-2012, 08:58 PM
  #8
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

The further the carb is closed or the LS needle leaned, the less siphoning will occur.
Ernie Misner is offline  
Reply With Quote
Old 10-22-2012, 04:04 AM
  #9
Old Fart
 
Old Fart's Avatar
 
Join Date: Apr 2008
Location: Perth, AUSTRALIA
Posts: 3,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Hi ernie if the fuel tank is high in relation to the carb with a saito single inverted then you need to completely have the throttle barrel shut or it will continue to dribble fuel..the tank not me i hope
Old Fart is offline  
Reply With Quote
Old 10-22-2012, 04:11 AM
  #10
Old Fart
 
Old Fart's Avatar
 
Join Date: Apr 2008
Location: Perth, AUSTRALIA
Posts: 3,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Never sweat on a cheerfull post,i've got a good idea about embarrassing thowhat about a you tube vid(shoulder cam of course)of our mate hairy knuckle dave riding a fatboy down his favourite stretch of straight road stark naked and a guitar strapped to his back.What movie theme music would be playing while all that went on guys
Old Fart is offline  
Reply With Quote
Old 10-22-2012, 07:02 AM
  #11
blw
Moderator
 
blw's Avatar
 
Join Date: Mar 2004
Location: Opelika, AL
Posts: 9,260
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Keep in mind that the factory setting for the low speed needle is sloppy rich. This is intended for the initial break in run on the engine.

If you have it that rich, you can watch all the smoke as you advance the throttle. If your high speed is set nearly right you can see the smoke begin to disappear near 80% throttle. This shows where the low speed stops having effect.
blw is offline  
Reply With Quote
Old 10-22-2012, 08:38 PM
  #12
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Right on Old Fart. If you have a switch on your tx set up for engine kill / carb fully closed position, you can shut the power off on the plane while it is in that position and you shouldn't get any siphoning.
Ernie Misner is offline  
Reply With Quote
Old 10-22-2012, 09:35 PM
  #13
fredscz
 
Join Date: Jan 2002
Location: Benton, IL
Posts: 725
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

While your at it change the prop as a 13x8 is way too small for a Saito 100. I agree with some of the other posters that your low end is probably too lean so after you change the prop richen up the low end and try again.
fred
fredscz is offline  
Reply With Quote
Old 10-22-2012, 11:23 PM
  #14
w8ye
Moderator
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,533
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

I had assumed that he was running A 3 blade 13 x 8?
w8ye is offline  
Reply With Quote
Old 10-23-2012, 04:15 AM
  #15
Old Fart
 
Old Fart's Avatar
 
Join Date: Apr 2008
Location: Perth, AUSTRALIA
Posts: 3,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Yeh i assumed that too.Anything over ten on that size prop sounds good to me,don't know whether it's a wide blade or not,adam ain't far off the mark.
Old Fart is offline  
Reply With Quote
Old 10-23-2012, 08:07 AM
  #16
AdamPrime
Thread Starter
 
Join Date: Oct 2012
Location: carlisle, PA
Posts: 6
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Yeah it is a 13x8 3 blade. I also tried a 14x9 3 blade. Seemed to struggle in flight with the 14.
AdamPrime is offline  
Reply With Quote
Old 10-23-2012, 08:28 AM
  #17
Scar
 
Scar's Avatar
 
Join Date: Oct 2002
Location: Peoria Hts, IL
Posts: 3,120
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems


Quote:
ORIGINAL: AdamPrime

Yeah it is a 13x8 3 blade. I also tried a 14x9 3 blade. Seemed to struggle in flight with the 14.
My Saito 100's are happy with a 15x6.

My low speed needle wound up flush with the throttle lever face, nothing protruding past the lever. Results may vary.

Good luck,
Dave Olson
Scar is offline  
Reply With Quote
Old 10-23-2012, 12:28 PM
  #18
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

I have a Saito 100 coming for a 3D profile plane. Will it pull a 16x4 APC Wide prop? That's the same prop my Saito 125 pulls though ... ?
Ernie Misner is offline  
Reply With Quote
Old 10-23-2012, 04:19 PM
  #19
Scar
 
Scar's Avatar
 
Join Date: Oct 2002
Location: Peoria Hts, IL
Posts: 3,120
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems


Quote:
ORIGINAL: Ernie Misner

I have a Saito 100 coming for a 3D profile plane. Will it pull a 16x4 APC Wide prop? That's the same prop my Saito 125 pulls though ... ?
I think you'll find a 15X4W a better fit, after you get the engine broke in.
Just my opinion.

Dave Olson
Scar is offline  
Reply With Quote
Old 10-23-2012, 04:24 PM
  #20
Ernie Misner
 
Ernie Misner's Avatar
 
Join Date: Jul 2002
Location: Tacoma, WA
Posts: 5,024
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems

Yeah, that makes more sense. The wide series props can be quite a load. Thanks.
Ernie Misner is offline  
Reply With Quote
Old 10-28-2012, 02:05 PM
  #21
AdamPrime
Thread Starter
 
Join Date: Oct 2012
Location: carlisle, PA
Posts: 6
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Saito 100 needle problems


Quote:
ORIGINAL: Ernie Misner

Is it possible that with that custom exhaust that you are not getting enough pressure to the tank somehow? I've had that happen and richening the HS needle didn't have much effect. Keep us posted, thanks,

Ernie Misner

It looks like it is a lack of muffler pressure is causing the problem. I switched back to the stock muffler for trouble shooting purposes. It cleared up all the issues I was having. I left the needle at the positon I had set it with the scale exhaust. With proper exhaust pressure it wouldn't even run without continuous glow heat. I leaned it out to the pointI had it running at 6000 rpms wot pulled off the muffler pressure and it surged to over 10,000. I guess I will have to switch to a perry pump of something to provide fuel pressure at the needle since the scale system doesn't provide enough pressure. Thank You Everyone for your help. Adam
AdamPrime is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 03:50 AM.