K&B 3.5 outboard repairs
09-10-2005, 11:35 AM
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K&B 3.5 outboard repairs
I can not keep this engine running once put into the water. I've run at every setting imaginable. Is there a repair / tune-up shop out there that I can send this?
09-10-2005, 11:45 AM
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RE: K&B 3.5 outboard repairs
What is going on with it? Needle should be 3 1/2 +/- turns out. Need to make sure the fuel tank is sealed, good fuel lines, no garbage in the carb / needle area. Does the piston have good compression? How do the bearings feel? Might need to take them out, all four, and spin by hand to verify... What glow plug are you using? Is this a 12mm or 13mm motor? The 12mm takes a "short" plug while the 13mm takes the "long" plug.
09-10-2005, 01:49 PM
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RE: K&B 3.5 outboard repairs
It is an older engine with several new part. (including new piston and sleeve) I have had all aprt several times, cleaned, re-cleaned and cleaned again. I've tried every plug at every setting. It has great compression. The engine runs absolutly great for 300 - 400 yarfds then will bog out like it is being choked. Will try and get a pic
09-10-2005, 03:31 PM
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RE: K&B 3.5 outboard repairs
How easy does the motor start up? If it's a pain to start, there may be an air leak somewhere. I've cracked several K&B 3.5 cases in my years. How does the motor perform before it dies? When it's started up, is there any hesitation before rev'ing up (just right!) or does it just scream (too lean)??? If, when on water, it screams and dies, it's lean. A rich motor would just lug around slowly, it may die, but the motor will never rev up.
Check the crank pin and con-rod for any scratches.. Just digging at items that might cause the issue at hand.
Ok, reread your last post.. Motor bogs out like it's being choked.. Sounds rich to me. What fuel (brand and %) are you using? The K&B 3.5 will run on low nitro but just loves 50% +... I've had good luck running the K&B L1 or MC-9 plugs on these motors...
Check the crank pin and con-rod for any scratches.. Just digging at items that might cause the issue at hand.
Ok, reread your last post.. Motor bogs out like it's being choked.. Sounds rich to me. What fuel (brand and %) are you using? The K&B 3.5 will run on low nitro but just loves 50% +... I've had good luck running the K&B L1 or MC-9 plugs on these motors...
