Go Back  RCU Forums > Glow Engines, Gas Engines, Fuel & Mfg Support Forums > Gas Engines
Up against the wall 53cc engine refuses to start >

Up against the wall 53cc engine refuses to start

Notices
Gas Engines Questions or comments about gas engines can be posted here

Up against the wall 53cc engine refuses to start

Old 08-17-2014, 01:33 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default Up against the wall 53cc engine refuses to start

Engine had been dependable right up until it just quit, it's a cermark 3mm 53cc. I had been flying it regularly, had one bad landing in the rough that broke off the muffler downtube, figured I go ahead and run it without the cowling, didn't seem like a big deal.
So the next day Sat. I start it up and run it fast idle to warm it up and it suddenly just quits as if it ran out of gas.
Been working on it ever since, all day yesterday all day today and still no go,
I pulled the tank and inspected the clunk and tube connections, leak tests good.
Pulled carb and reed block, carb clean as a whistle, settings all checked out, reassembled with all new gaskets, still no go, engine pops and sputters randomly, sometimes floods.out.
Pulled reed block and wet sanded all flat and true all good.
Ignition is an rcexl running on a good 4.8v nicad. With plug just stuck into lead wire have good spark visual and snap sound, timing has not moved, pickup in same position as always.
I've pulled the carb apart about 4 times, practically slept with it last night. I though today would be for sure a running motor but nope still no go, last thing I tried same fresh 50:1 mix but no dice still just get a random pop and sputter, something is not right I can't figure it out need help!
Old 08-17-2014, 02:14 PM
  #2  
My Feedback: (5)
 
All Day Dan's Avatar
 
Join Date: Dec 2002
Location: MANHATTAN BEACH, CA
Posts: 4,606
Received 3 Likes on 3 Posts
Default

Start changing things one at a time. Plug, ignition, switch, sensor, etc.. Dan.
Old 08-17-2014, 04:58 PM
  #3  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

Ok thanks, I'll take your advise and bypass the ignition switch and power the module direct, can a spark plug go bad, other than physical damaged like cracked porcelan? The ignition makes a fat blue spark every time the magnet passes the sensor, I took an old plug and opened the gap to about 1/4" and spark jumped the gap! I'm baffled sick.
Old 08-17-2014, 05:44 PM
  #4  
My Feedback: (5)
 
All Day Dan's Avatar
 
Join Date: Dec 2002
Location: MANHATTAN BEACH, CA
Posts: 4,606
Received 3 Likes on 3 Posts
Default

Spark plugs are notorious for going bad. The may look and act good out of the cylinder but fail under compression. Dan.
Old 08-18-2014, 01:57 AM
  #5  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

I never knew that! Thanks,new to model airplane engines, been around chansaw and weedwackers all my life majority of problems are fuel lines, never a bad plug but there's always a first I sure hope thats all it is.
My plug has no writing whatsoever on it, a 9/16 socket fits it somewhat so it's probably it's metric equiviant, have any suggestion on the plug to replace it with, thanks.

Last edited by a70eliminator; 08-18-2014 at 02:00 AM.
Old 08-18-2014, 09:48 AM
  #6  
CK1
My Feedback: (60)
 
CK1's Avatar
 
Join Date: Apr 2002
Posts: 1,552
Received 24 Likes on 17 Posts
Default

I would replace the plug with a new one and take a look inside the spark plug cap and be sure the silicon boot isn't torn . It is not uncommon for the boot to tear during a crash even if the spark plug cap and plug don't appear to be damaged . Spark may appear normal with the plug resting in the cap but may not fire when the plug is installed and loaded with fuel/air mixture. The higher resistance of being installed and wet will caused the spark to follow the path of least resistance (grounding through the tear in the boot ).
Old 08-18-2014, 01:48 PM
  #7  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

Ok , all the ignition components iare on the bench where I could study them better, with A 4.8V pack plugged in and a small magnet passed along the sensor sparkplug inserted, I get good spark 3 or 4 times then a no spark then 3 or 4 good and another bad, during the times of bad I hear a slight snap inside the boot.
So without a sparkplug in the boot I get spark jumping from deep within the silicone insert straight out to the metal case, it snaps with great power every time hmmm this can't be right so now i'm in the process of removing the boot and getting a better look at the silicone insulator, looks like it's going to be fun, well at least i think the igniton box is good.
Old 08-18-2014, 02:05 PM
  #8  
Senior Member
 
3136's Avatar
 
Join Date: Oct 2010
Location: Victoria, AUSTRALIA
Posts: 973
Likes: 0
Received 6 Likes on 6 Posts
Default

Look at post 36 of the sticky http://www.rcuniverse.com/forum/gas-...rmation-2.html
Old 08-18-2014, 02:08 PM
  #9  
Senior Member
 
3136's Avatar
 
Join Date: Oct 2010
Location: Victoria, AUSTRALIA
Posts: 973
Likes: 0
Received 6 Likes on 6 Posts
Default

Then look at post 15 here http://www.rcuniverse.com/forum/gas-...-question.html
Old 08-18-2014, 02:16 PM
  #10  
Senior Member
 
3136's Avatar
 
Join Date: Oct 2010
Location: Victoria, AUSTRALIA
Posts: 973
Likes: 0
Received 6 Likes on 6 Posts
Default

And if that is your problem http://www.valleyviewrc.com/estore/e...cessories.html
Old 08-18-2014, 02:56 PM
  #11  
My Feedback: (5)
 
All Day Dan's Avatar
 
Join Date: Dec 2002
Location: MANHATTAN BEACH, CA
Posts: 4,606
Received 3 Likes on 3 Posts
Default

I hate to be the bearer of bad news, but it is possible to destroy an ignition module with no spark plug attached. I don't know if that applies to the one you have. Send an email to the manufacturer and find out. Dan.
Old 08-18-2014, 04:28 PM
  #12  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

Cant be much worse than whats been going on as the escaping current spark has actually burnt a tiny hole right through the silicone boot, it seems to still be delivering current and i'm confident a new insulator boot will fix, if not I'll just have to buy another complete unit.
Old 08-18-2014, 08:06 PM
  #13  
My Feedback: (6)
 
av8tor1977's Avatar
 
Join Date: May 2003
Location: Tucson, AZ
Posts: 7,219
Likes: 0
Received 2 Likes on 2 Posts
Default

A new silicone inside the plug cap should fix it.

AV8TOR
Old 08-20-2014, 11:27 AM
  #14  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

I took a couple pics of where the silcone insulator broke down, you can see where the spark had burnt it's way right through and was arcing to the metal sheild causing mis fire and evenetually total ignition failure.
Attached Thumbnails Click image for larger version

Name:	20140818_180802.jpg
Views:	117
Size:	1,015.2 KB
ID:	2024008   Click image for larger version

Name:	20140818_180742.jpg
Views:	81
Size:	1.34 MB
ID:	2024009  
Old 08-20-2014, 01:48 PM
  #15  
CK1
My Feedback: (60)
 
CK1's Avatar
 
Join Date: Apr 2002
Posts: 1,552
Received 24 Likes on 17 Posts
Default

If after replacing the boot and cap the engine wants to run but runs poorly the ignition module itself may have been damaged as well. An open in the high voltage line can damage the triggering components inside the module. It's about a 50/50 chance.
Old 08-20-2014, 04:27 PM
  #16  
Senior Member
Thread Starter
 
Join Date: Jun 2012
Location: mogadore, OH
Posts: 473
Likes: 0
Received 2 Likes on 1 Post
Default

Well, I got anxious because my boot is on backorder from CH Ignitions. I applied 100% silicone sealant into the cut with a needle and also coated the inside of the boot with silicone stuck the plug into it and let cure overnight. Today I cut the plug loose pulled it out of the isulator and re-assembled everything, I applied plenty of non conductant tune up grease into the boot and stuck it onto the sparkplug. The engine fired immediately and is back to running as it's usual 6800RPM 22x10 on the ground with a smooth dependable idle, now I'm going to quit while I'm ahead and not mess with it anymore till the new boot arrives. I evidently have an exceptional good ignition module to be still functioning, according to some of you I toasted it 3 times over, but thanks for all the red flags I will be more careful from now on.

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
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.