Fuel for old 3.5 K7B OB engine?

All outboard, inboard and aero questions answered here.
ALSO Veco, Torpedo, Fury, & Stallion

Moderator: SteveM

Fuel for old 3.5 K7B OB engine?

Postby Ron » Sun May 02, 2010 4:53 am

I have a 3.5 engine that a friend gave me a few years ago. I ran it then on SIG 15% fuel. It was hard to start then. I want to use it now and would like a fuel brand recommendation. I have read the manual for the engine and the FAQ's about fuel. The FAQ's say 25% nitro with 18% oil with a 50/50 mix of castor oil to synthetic as I read it. I went to several hobby shops and most fuels don't list mix especialy in regard to oil ratios.
Thanks in advance for any abvice

Ron
Ron
 
Posts: 1
Joined: Sun May 02, 2010 4:39 am
Location: PA

Postby MECOA » Mon May 03, 2010 8:36 pm

I know. Most fuel mfg's don't list oil as if it is some big secret. They when your engine is fried it's our fault. 18% is the least.

Call the fuel makers and ask/complain. Maybe they will get the message.
Most will tell you over the phone.
MECOA
Site Admin
 
Posts: 1095
Joined: Mon Jun 30, 2003 9:48 pm

Postby SteveM » Tue May 04, 2010 12:21 am

When I was racing the K&B 3.5 outboard in IMPBA sanctioned races I would run Byron 25% nitro fuel. I would add 1oz of Sig AA Castor oil to each jug as a bit of extra protection. I never had an issue and my motors.
SteveM
 
Posts: 242
Joined: Mon Nov 20, 2006 10:33 am
Location: Ottawa, Ontario, CANADA

Postby HappyOne » Wed May 05, 2010 6:48 pm

If I can get Redmax or other boat fuels I use that but lately I have been running Coolpower heli fuel. Not the same power as the 50% + boat fuels but enough lubrication and goes fine for sport running.
HappyOne
 
Posts: 11
Joined: Fri Sep 25, 2009 9:49 am
Location: Kitchener, Ontario


Return to K&B Mfg. Engine Tech Questions

Who is online

Users browsing this forum: No registered users and 16 guests