help .... k-45

[jfpracing]

...Just started my new k-45 and i am not able to get a good mixture

that thing is running lean ... I tryed a cmb67 and a picco exr67 needle valve

with no results... I started the engine wihtout needle valve at all and the result was

not bad ...I am sure i can put the boat on water with no problem. I have 45%

wildcat , pipe is 10.250 and it' s an ops 45 .

I am sure there is somebody that have an answer for me.

I find the v-groove on the drum of the carb a bit small ....should I

make it bigger ???

thank you !

-jf

 

[Anders_Martinelle]

You have found the problem,the V-grove IS to small.

I have seen that to often.........

Run less then 25% nitro and it might work.

Or mount a nother carb.........

Anders

 

[Mike Hughes]

The low end needle on the stock carb sucks. To difficult to set up with the high nitro. Don't mod the barrel. Mod the aluminum end cap with the hole through it. I ended up just cutting a slot with the dremel cutoff wheel where the fuel passes through the hole into the barrel groove. Center it up on the barrel groove and the problem will disappear. You basically eliminate the low end needle.

Mike

PS Or a new carb works too.

 

[TimD]

Mike,

Are you still using the caged needles / steel rod?

Tim.

 

[Jerry Wyss]

This sounds alot like the way my modified K&B 7.5 was running a while back,,I practicaly had the needle

out and i t ran better. It had ripped a slice in the tuned pipe coupler. Replaced the coupler,,but it still

went lean approching full throttle no matter how far the needle was out. after that I installed, (and I Know

most of you are gonna think I'm Nuts) a check valve, (YS) in the pipe pressure line and YEEHA! that

mod-motor came to life Finally. They only cost 5 bucks, try it.

 

[Mike Hughes]

I am running the bushed rod now. Alan Hobbs had them made last year and he sent me one to try. The K45 never had a steel rod. It was aluminum. It ran a caged bearing. Out of all the K motor , the 45 is the only one that you can not put a full compliment of bearings in. That is because the way that the crank is built. I have been doing some testing with a larger carb than the stock. I am running a .405" bore, that coupled the 45 parabolic and she is starting to come around.

Mike

 

[TimD]

Thanks for the info Mike,

The K45 is the only one I'm missing - got the 67, 82 and 90 and run full compliment needles in all of them.

Are you happy with the bushed rod?

Tim.

 

[Mike Hughes]

Working great so far. No signs of under do wear. Haven't run it much. It has been to 2 races so far.

Mike

 

[TimD]

Sorry for all the questions but what hull / prop are you using it with?

 

[jfpracing]

what about performance ? is it like a mac or not ... what pipe are you using and

what percentage of fuel... sorry for all these questions but I am the first one in our

local club to race a k and I have no clue what to expect h34r: h34r: h34r:

jf

 

[Mike Hughes]

K45 with high nitro head, 60%, head clearance .012", 45 silver parabolic pipe with internal stinger drill out to stinger size, 1457 with slight cup on the tips, .405" carb, 45 Eagle SG. I am not sure of the performance of the MAC 45, as I don't own one. Can't compare. I still need more time to test. Don't have any time to go to the lake so I do it at the races. Last race was pretty rough and boat wasn't handling to good in the corners. Probably in the 65 mph range. Set conservatively on the pipe length at 10". I will be pushing that in next race should do a lot better at 9 5/8" and some smooth water.

Mike

 

[Anders_Martinelle]

JF,the K45 has not the same performance as a MAC 45.

If you run MAC race speed around 80 is common but i have NEVER seen that with a K45....

But the K45 is a very nice engine (i have 3 of them) and they run in the 70-72mph range.

Anders

 

[Ron Olson]

Mike, the bushed con rod sounds like the answer to the problems that I had with mine. It tossed the needle bearings twice and after having Al Hobbs rebuild it once for a little over $200.00 I decided to let the motor set and bought another motor. Tim is getting it as soon as we get some things squared away.

 

[TimD]

Anders,

What is your opinion for the difference in performance?

Mike,

Thanks for the info

Ron,

We'll get there eventually!

Tim.