CMB On a K&B Lower

[nitrotoys]

CMB On a K&B Lower

has anyone ever put this combo tougher?

(they say that the CMB power head will bolt right on) If so what kind of pipe would you all suggest? and with the added horsepower, what would be a good prop to first start with?

going on a tunnel boat.

Thanks guys for all or any info

Tom

 

[billr]

Re:CMB On a K&B Lower

Is your lower end a 3.5 or a 7.5? I have a CMB 3.5 Greenhead that I am putting on a 7.5 K&B foot with a carbon fiber pipe. I have put a Greenhead cmb on a K&B lower 3.5, but really did not like it due to the stress on the cable(it takes it a true 90 degrees in a very short space). I put a lawless outdrive on it and it did ok, but the metal is soft. Mark Hopper Silver Bullet pipes are really good! His pipes are evolving as the design improves. The latest versions are really good!!! Otherwise I would then go to an Irwin. On the 3.5 K&B, just keep your lower unit really lubed up. I started using a combo mixture that really works great. Once I started using it, I have never broken a shaft. You have to really shake this stuff up before you put in in the unit, but it is as follows: 1/3 20 weight oil, 1/3 STP, 1/3 Automatic Transmission Fluid. Although lately I have used a higher percentage of ATF... it seems to work even better!

Billy R.

 

[nitrotoys]

Re:CMB On a K&B Lower

YES it is a 3.5 lower.

and thanks for the info on the pipes and the lube stuff. But dont it run out or does the STP keep it sticky to stay in there? and HOW do you inject it to lube it?

I ran the K&B Motor and used a high temp grease (syn ) and a little bit of gear oil 80/90 Weight, it seemed to have worked good so far, that great is real sticky, has a high heat tolerence.

where is a good place to by the irwin pipe, and or the other pipe you had talked about??

Thanks for the info

Tom

 

[Precision Boats]

Re:CMB On a K&B Lower

Hi Tom,

You have got mail.

Tim

Precisionboatsracing.com

 

[waterbug]

Re:CMB On a K&B Lower

Billy,

What did you have to do to the 7.5 foot or engine for it to fit??? I asked J.Irwin about that, but he strongly recommended the Lawless. I couldn't afford the engine and the lawless at this time.

 

[Joe]

Re:CMB On a K&B Lower

TO USE THE 7.5 FOOT YOU'LL HAVE TO GET TIM AT PRECISIONBOATS.COM TO MAKE YOU A PIECE TO PUT IN YOUR PTO TO FIT THE 7.5 SHAFT. CENTER YOUR PTO ON YOUR ENGINE TO THE FLEX SHAFT ON THE TOP OF THE K&B 7.5 FOOT. MARK YOUR HOLES. YOU CAN DRILL AND TAP THEM OR YOU CAN JUST DRILL THEM AND USE ALLEN SCREWS AND LOCK NUTS. I RUN THIS SET UP AND WORKS GREAT. IF YOU LOOK AT OTHER PEOPLES BOATS AT THE RACES YOU WILL SEE A LOT OF PEOPLE DOING THIS. I'VE ONLY REPLACED ONE FLEX SHAFT RUNNING A NOVAROSSI ON MINE WHICH HAS A LITTLE MORE POWER THAN THE CMB.

JOE

 

[Precision Boats]

Re:CMB On a K&B Lower

Waterbug

get in touch with me if you need that work done or help.

Tim

Precisionboatsracing.com

[email protected]

p.s. that setup does work good I can also supply the 7.5 foot (k& B)

 

[waterbug]

Re:CMB On a K&B Lower

Hey Tim,

Sounds good to me !!! I'll give you a "holler"

as soon as OLD JERRY gets them New plans done!! Do you have the flex shafts for OS & K&B ??

Has any one tryed this with the OS foot??

I know it has a odd shape, I read were someone said that only a OS would fit.

 

[billr]

Re:CMB On a K&B Lower

Ok, well each to their own with the lower units, but I have no profit in the matter. I will give you my honest opinion. I have seen both, and have ran a lawless myself. Lawless are ok, look great, but have really soft metal. Myself and others in the club have had bent skegs because of minor bumps. The guys in the club who run the 7.5 foot, well they swear by them, never see them hook near as bad, and really the advantage is that you WILL NOT break as many cables. The 7.5 cable is much larger and stronger. The guys who have been running them over the past two years have broken 1 each, as to others many on the 3.5 cables. &.5 foot is the way to go if you want to race and also save money on cables.

As far as injecting the lube, will if you look at the mounted engine from the rear of the boat, you need to look at the side of the lip where the engine and lower unit are joined. There will be a tiny whole. This is the same on the 7.5 K&B and lawless. You take an oil can, or some type of squirt gun( like a an old oil can) and squeeze it in until it runs out ofthe whole down near the drive dog. Some guys use grease, but you must take the cable out ever time. Most of the racers here inject their own lube concoction after and before every run of the engine. This keeps a good coat of fresh lube in the tube.

As far as the STP, well I did it because Irwin told me to. I have almost taken it out of the lube mix, because of the Transmission fluid a nd the 20 weight oil.

The ATF just really seems to join easier with the 20 weight and ATF just really has worked for me.

I belive in experimentation with the lube. Is used the STP and 20 weight alone for a while, and I broke shafts. Once I started in with the ATF... no shafts have broken, but I lube after every run, no matter how short it was!

Hope this helps.

Billy R.

 

[Precision Boats]

Re:CMB On a K&B Lower

Waterbug,

We carry all kinds of parts including shafts. Try some of Billy's grease I think it will work, Billy does it have a little shine in it also,maybe 100 proof??????????? ;D

Tim

 

[waterbug]

Re:CMB On a K&B Lower

Onething I learned from my gokart & drag racing days, synethethic is the only way to go !!!. There's nothing out there better!!! Except N.A.S.A.!!!

As a matter of fact, I had trouble in my blue oval drag engines of after 1.5 years of running ,still have a crosshatch pattern in the cylinders !!! Had to break-in with std. motor oil !! NO ADDITIVES could be used, or you won't get a good seatting of the rings!!!! not with chrom-molly or plasma rings, maybe with castiron rings!! BEEN THERE, DONE THAT !!

I'M NOT KNOCKING ANYONES FORMULA!!!! " TO EACH HIS OWN "

" IF IT WORKS DON'T FIX IT "