Go Back  RCU Forums > RC Boats > Speed - RC Nitro Boats
Reload this Page >

outboard cuts out at top speed

Notices
Speed - RC Nitro Boats For all your rc nitro fuel burning boating needs.

outboard cuts out at top speed

Old 04-24-2005, 03:14 PM
  #1  
r/cmark42
Thread Starter
My Feedback: (8)
 
Join Date: Jun 2004
Location: Middleport, NY
Posts: 568
Likes: 0
Received 0 Likes on 0 Posts
Default outboard cuts out at top speed

I have a K&B 3.5 outboard with gold carb and tuned pipe. I have attached to a tunnel haul and if the thing had wings, it would fly! Problem..Once it hits top speed, the engine bogs out after 3-4 seconds. any suggestions? I have played with the needle, richening and leaning does not seem to effect this situation
Old 04-24-2005, 03:30 PM
  #2  
ob nut
My Feedback: (1)
 
ob nut's Avatar
 
Join Date: Mar 2005
Location: Cincinnati, Oh
Posts: 1,350
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

I had this issue before. What fuel tank(s) you using? If you don't have a hopper tank, might want to get one of the new ones from Jim Irwin. They are sweet. Other options: Bearings good? Might want to replace the fuel lines. Needle should be anywhere from 3 - 4 turns out. Good starting point is 3 1/2 turns out.
Old 04-24-2005, 03:54 PM
  #3  
*JCB*
My Feedback: (9)
 
*JCB*'s Avatar
 
Join Date: Sep 2004
Location: Long Beach, CA
Posts: 689
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

make sure your fuel tank is properly sealed and you are getting proper pressure from you muffler. sounds like the motor is being starved of fuel, also try giving your carb a real good cleaning and blow out w/ compressed air
Old 04-24-2005, 06:46 PM
  #4  
Tricksligger
Senior Member
 
Tricksligger's Avatar
 
Join Date: Nov 2004
Location: south, FL
Posts: 634
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

It sounds like a simple case of running too lean. I know you said you tried richening it but maybe you didnt go far enough. If it had to do with your fuel tank or lines it would cut out at any speed. When its just at top speed it usually means your too lean. I dont own a r/c boat...
but....

I did stay at a holiday Inn last week[X(].
Old 04-25-2005, 11:50 AM
  #5  
r/cmark42
Thread Starter
My Feedback: (8)
 
Join Date: Jun 2004
Location: Middleport, NY
Posts: 568
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

Thanks for the information, I will start experimenting further this week...
Old 04-28-2005, 07:39 PM
  #6  
jetpack
My Feedback: (1)
 
jetpack's Avatar
 
Join Date: Oct 2002
Location: Hobart, IN
Posts: 2,477
Likes: 0
Received 2 Likes on 2 Posts
Default RE: outboard cuts out at top speed

Mine i found out was starving for fuel at speed, cause the stock exhaust didnt have any pressure to it, i had to raise it up as high as i could under the cowl for it to gravity feed better.
Old 04-29-2005, 06:56 AM
  #7  
r/cmark42
Thread Starter
My Feedback: (8)
 
Join Date: Jun 2004
Location: Middleport, NY
Posts: 568
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

Well, based on replies submitted, I have cleaned out old fuel tank, installed new lines, removed and cleaned out carb, will raise tank and richen fuel mixture. If this stupid weather clear up, I will let you know soon how it all works out
thanks for all your replies!
Old 05-02-2005, 08:28 AM
  #8  
Satkunas
Member
 
Join Date: Oct 2002
Location: S㯠Caetano, BRAZIL
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

Hey I just ran my boat yesterday and I think I have a setup almost like yours. I have a Quickie 40 with a K&B 3,5ss gold head and carb.

I had the same problem yesterday, but as someone said before I went far and now I can say that this engine loves fuel...........

My boat was running almost like yours, at top speeds my engine just die........So I openned the fuel valve 1 and 1/2 turn and now the engine is running perfect !!!!!!!

For start the engine is pretty easy, and until launch the boat in the water, you need to get the carb almost totally open, cause the engine runs too much rich.....but after you hit the water, (with the load in the prop) the engine become full power !!!!!!!!!!

Hope it helps you !!!

Henrique from Brazil


Attached Thumbnails Click image for larger version

Name:	Zx71693.jpg
Views:	24
Size:	144.8 KB
ID:	265817  
Old 05-02-2005, 10:06 AM
  #9  
r/cmark42
Thread Starter
My Feedback: (8)
 
Join Date: Jun 2004
Location: Middleport, NY
Posts: 568
Likes: 0
Received 0 Likes on 0 Posts
Default RE: outboard cuts out at top speed

Thanks all again.
Went out this weekend with all changes made. I'll be darn if the thing still died out at the top. My neighbor (great guy) had an exrta carb. On a hunch we changed mine out for his. (Gold to Red) Once the red carb was installed it ran sweeeeet!!!
I'm not sure the reasons why, but who am I to argue when something works

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 - 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.