Go Back  RCU Forums > RC Cars, Buggies, Trucks, Tanks and more > RC Giant Scale Cars
Reload this Page >

King motor 29cc loss compression after tuning.

Notices
RC Giant Scale Cars For all those who love driving large scale rc cars share your projects or ask questions here.

King motor 29cc loss compression after tuning.

Old 08-02-2012, 09:26 AM
  #1  
kaktus00
Junior Member
Thread Starter
 
Join Date: Apr 2012
Location: , POLAND
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default King motor 29cc loss compression after tuning.

Hi. Today when i ride baja something shot and engine loss compression. I thought it was pullstart but it's not it. Pullstart run slightly and when the piston moves to the top it sounds metallic and run hard. What's happened? Recently i changed oryginal carb to walbro 668, pipe to ddm dominator and NGK Iridium spark plug. Power strongly increased, did engine could not stand this power?
Old 08-02-2012, 09:32 AM
  #2  
Twin_Flyer
My Feedback: (4)
 
Join Date: Jan 2002
Location: Westhampton Beach, NY
Posts: 860
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

Maybe you ran it too lean?

Pull the plug and check the piston. You might have burned it.

Bill S.
Old 08-02-2012, 09:41 AM
  #3  
kaktus00
Junior Member
Thread Starter
 
Join Date: Apr 2012
Location: , POLAND
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.


ORIGINAL: Twin_Flyer

Maybe you ran it too lean?

Pull the plug and check the piston. You might have burned it.

Bill S.
I don't think so, I ran it rich (1,5 turn on h needle), it smoked perfect and spark plug also is perfect. It burn only 7 liters...

Old 08-02-2012, 01:33 PM
  #4  
savagecommander
Senior Member
 
Join Date: Jan 2006
Location: sterling heights, MI
Posts: 1,857
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

Pull the head and inspect. If the engine ingested something you may only be out a head but running it more could blow the whole thing
Old 08-05-2012, 05:12 AM
  #5  
kaktus00
Junior Member
Thread Starter
 
Join Date: Apr 2012
Location: , POLAND
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

http://imageshack.us/photo/my-images/402/imga0007k.jpg/
http://imageshack.us/photo/my-images/715/imga0006h.jpg/
http://imageshack.us/photo/my-images/811/imga0005n.jpg/
http://imageshack.us/photo/my-images/846/imga0004.jpg/
http://imageshack.us/photo/my-images/228/imga0003r.jpg/

It doesn't look good...
OK, what now? I intend to mount zenoah 36mm piston to the KM engine. Did it works together?

Old 08-05-2012, 12:16 PM
  #6  
sparky 25
 
sparky 25's Avatar
 
Join Date: May 2005
Location: Derry, IRELAND
Posts: 1,471
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

I had a needle bearing let go on my km 28.5cc engine,

It left worse drag marks down the side of the piston and liner than that of what is on yours,

I cleaned the engine out and reassembled it using a new bearing it would not start and compression was way down,

So I pulled it apart, replaced the piston ring as they are real cheap, i thought i would try to work with what i had
and it was back to running great, even pulling wheelies

You need to take a look and see what made the marks on your piston, clean out the motor with petrol and replace the bearing if that done the damage,

You may well need to replace the whole motor, but I would definitely try a new piston ring on what you have first,

Some pics on this post http://www.rcuniverse.com/forum/fb.asp?m=9001819
Old 08-05-2012, 04:24 PM
  #7  
savagecommander
Senior Member
 
Join Date: Jan 2006
Location: sterling heights, MI
Posts: 1,857
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

The head is done. The marks on the transfer roofs are death to that cylinder. The piston is also done for. Inspect the crank, find out if a needle came out of one of the needle bearings. If not, and there is no damage to the crank or cases(sometimes they can be bad) just throw the 36mm head on with a good gasket, fresh piston and new bearing.
Old 08-06-2012, 04:46 AM
  #8  
kaktus00
Junior Member
Thread Starter
 
Join Date: Apr 2012
Location: , POLAND
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

Ok, thanks for opinions. I noticed two more things. First > http://imageshack.us/photo/my-images/88/imga0027k.jpg/
The engine can run with it? Second thing > http://www.youtube.com/watch?v=kw_n_...ature=youtu.be - it's normal?
i'm going to buy this kit - http://www.davesmotors.com/s.nl/c.88...t.A/id.8021/.f but i've got 2 bolt in engine not 4. Did i can drill in the engine?
Old 08-06-2012, 05:15 AM
  #9  
hooleydog
My Feedback: (24)
 
Join Date: Nov 2003
Location: SOUTHFIELD, MI
Posts: 188
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

Nope you can't drill the extra 2 holes. Just get this and use you other parts like fan, carb, pull start, covers ect (That's what I did)..

http://www.ebay.com/itm/4-BOLTS-30-5...item2a1d08f727
Old 08-06-2012, 08:06 AM
  #10  
kaktus00
Junior Member
Thread Starter
 
Join Date: Apr 2012
Location: , POLAND
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.


ORIGINAL: hooleydog

Nope you can't drill the extra 2 holes. Just get this and use you other parts like fan, carb, pull start, covers ect (That's what I did)..

http://www.ebay.com/itm/4-BOLTS-30-5...item2a1d08f727
Did you have this kit? It's suspiciously cheap... how many gallon you have on it?

Old 08-06-2012, 09:49 AM
  #11  
hooleydog
My Feedback: (24)
 
Join Date: Nov 2003
Location: SOUTHFIELD, MI
Posts: 188
Likes: 0
Received 0 Likes on 0 Posts
Default RE: King motor 29cc loss compression after tuning.

Yep I bought the kit cos of the 4 bolt head , and it's 30.5cc too. Runs great too (just do a careful break in. Then your good to go)..

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


Thread Tools
Search this Thread

Contact Us - 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.