K&B Engines

[Ken Webb]

Anyone still running any 7.5 inboard marine eng.? I have 2 complete engs. that are over 20 yrs. old with low run times. Also have 1 K&B tuned pipe that was avail. at the time. Had to put new bearings in one eng. Both engs. have good compression. Would they still be somewhat competative now days?

 

[moparbarn]

drum or disc, maybe "somewhat" competitive, front intake, not so much.......they can be made to run fairly well, but reliability goes down as power comes up. i know that's true for most any engine, but they aren't called kabooms for nothing . with a VERY good set up, nail the start & hog lane 1, you can do ok.

 

[Ken Webb]

drum or disc, maybe "somewhat" competitive, front intake, not so much.......they can be made to run fairly well, but reliability goes down as power comes up. i know that's true for most any engine, but they aren't called kabooms for nothing . with a VERY good set up, nail the start & hog lane 1, you can do ok.

 

[Ken Webb]

drum or disc, maybe "somewhat" competitive, front intake, not so much.......they can be made to run fairly well, but reliability goes down as power comes up. i know that's true for most any engine, but they aren't called kabooms for nothing . with a VERY good set up, nail the start & hog lane 1, you can do ok.

 

[Ken Webb]

Rotor w/ rear carb. on backplate.

 

[moparbarn]

disc's are better, imo. drum rotor k&b's suffer from crankcase volume issues. they are still better than front/crank induction k&b 7.5's, though. parts would be an issue...... i have a crank & some ex. throttles for that engine. need to know crank pin diameter, there are 2 versions.

 

[Lennard Cuenco]

i love passing cmbs, rossi's, picco's on the outside with my old kaboom's...LOL

work at ur setup, deck clearance around .013 and let'er fly

ps - call andy for a good prop too

 

[moparbarn]

yeah, there is a perverse pleasure in that B) !!

 

[Andy Greene]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

 

[Bill Gibson]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

 

[dwilfong]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

I started with a K&B 7.5 IB 2 1/2 years ago. The eng was real light and had all kinds of power with the drum rotor and a .400 carb. Would rev its a$$ off. But would break all the time. The pistons would break and the small bridge on the drum would break. If you could get a good piston they would be a very good rigger eng. Run it but don't cut the pipe shorter than 10 1/4" this will keep it from over reving. In a light boat it should be a very good setup.

David

 

[Bill Gibson]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

I started with a K&B 7.5 IB 2 1/2 years ago. The eng was real light and had all kinds of power with the drum rotor and a .400 carb. Would rev its a$$ off. But would break all the time. The pistons would break and the small bridge on the drum would break. If you could get a good piston they would be a very good rigger eng. Run it but don't cut the pipe shorter than 10 1/4" this will keep it from over reving. In a light boat it should be a very good setup.

David

David, did you run yours in a rigger? Just curious!!

 

[Andy Greene]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

LMAO - replied . And thats cause I only ride the elevator in the womans department at Macy's - he's jealous

Robin , Im pretty sure your banned from the 3 R'S

- Delivering a shot via PM for someone else to pass on = (SOFT)

Shave your beard immediately and tell the sheep to get back out to the pasture.

Rick and Ray are gonna have to have a talk with ya .........................

Never got to see that one run Bill, he had already moved on to the lightweight dont hit a buoy boat by them- you guys are old , remember

Sorry for the Hi-Jack spider , run the heck out of em if you have em- at very least they make cool parts to hang from your key ring

Andy

 

[Lennard Cuenco]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

LMAO - replied . And thats cause I only ride the elevator in the womans department at Macy's - he's jealous

Robin , Im pretty sure your banned from the 3 R'S

- Delivering a shot via PM for someone else to pass on = (SOFT)

Shave your beard immediately and tell the sheep to get back out to the pasture.

Rick and Ray are gonna have to have a talk with ya .........................

Never got to see that one run Bill, he had already moved on to the lightweight dont hit a buoy boat by them- you guys are old , remember

Sorry for the Hi-Jack spider , run the heck out of em if you have em- at very least they make cool parts to hang from your key ring

Andy

if ur breakin stuff...ur doing it wrong



http://i1217.photobucket.com/albums/dd385/u37scale/kaboom001.jpg

if your not breakin stuff..ur not trying hard enuf

 

[Tom Foley]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

LMAO - replied . And thats cause I only ride the elevator in the womans department at Macy's - he's jealous

Robin , Im pretty sure your banned from the 3 R'S

- Delivering a shot via PM for someone else to pass on = (SOFT)

Shave your beard immediately and tell the sheep to get back out to the pasture.

Rick and Ray are gonna have to have a talk with ya .........................

Never got to see that one run Bill, he had already moved on to the lightweight dont hit a buoy boat by them- you guys are old , remember

Sorry for the Hi-Jack spider , run the heck out of em if you have em- at very least they make cool parts to hang from your key ring

Andy

if ur breakin stuff...ur doing it wrong



http://i1217.photobu...e/kaboom001.jpg

if your not breakin stuff..ur not trying hard enuf

Yeah right !! I still wonder why someone has not duplicated the KB platform with reliable parts that dont blow up so readily . Steel rods weigh more but don't break in todays stuff . My last MAC 45 was a ballistic missle ..this motor needs to be replicated !!!!!!

 

[dwilfong]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

I started with a K&B 7.5 IB 2 1/2 years ago. The eng was real light and had all kinds of power with the drum rotor and a .400 carb. Would rev its a$$ off. But would break all the time. The pistons would break and the small bridge on the drum would break. If you could get a good piston they would be a very good rigger eng. Run it but don't cut the pipe shorter than 10 1/4" this will keep it from over reving. In a light boat it should be a very good setup.

David

David, did you run yours in a rigger? Just curious!!

Bill I ran it in a Dumas DV 40 that I ran a surface drive on. It was my first boat and would run like a scalded dog. But it would not stay on the water even with 1lb of lead under the eng.

Thats when I got old 666 and ran it in it for a few runs till it went KABOOM 2 times and moved on to the 45RS I run today. That 7.5 ran as fast as my 45RS just could not keep it to geather at 30000 RPM. Would pull the same props I run with the RS in the Cal Craft.

The rod and case never failed just keeps breaking the piston skirts and the small drum bridge.

It's funny the K&B drum looks just like the new VAC setup.

I want to put it in my 21 rigger if I can get a piston for it. The eng will drop right in and weighs no more than my MAC 21. Now that would be a ride.

David

David

 

[Lennard Cuenco]

yeah, there is a perverse pleasure in that B) !!

Till it makes that wonder sound -

KABOOM

And yes Robin , I run a 3.5 Gold Head on my ModVP - and I know that noise first hand

Andy

Andy, first ive got a message for you from someone you think alot of....ill PM ya! Second, Do you remember that 40 hydro that Norm Doerr ran with a KABOOM in it? I think it was a Hawk or a Roadrunner, but that thing was QUICK! I wish i had the time to build a super light 40 hydro and run a KABOOM in it...maybe twist Martys arm to do "things" to it to make er GO!...till it blows!....i still like KABOOMS! It is kinda fun to beat money every now and then! Spider...RUN EM!

LMAO - replied . And thats cause I only ride the elevator in the womans department at Macy's - he's jealous

Robin , Im pretty sure your banned from the 3 R'S

- Delivering a shot via PM for someone else to pass on = (SOFT)

Shave your beard immediately and tell the sheep to get back out to the pasture.

Rick and Ray are gonna have to have a talk with ya .........................

Never got to see that one run Bill, he had already moved on to the lightweight dont hit a buoy boat by them- you guys are old , remember

Sorry for the Hi-Jack spider , run the heck out of em if you have em- at very least they make cool parts to hang from your key ring

Andy

if ur breakin stuff...ur doing it wrong



http://i1217.photobu...e/kaboom001.jpg

if your not breakin stuff..ur not trying hard enuf

Yeah right !! I still wonder why someone has not duplicated the KB platform with reliable parts that dont blow up so readily . Steel rods weigh more but don't break in todays stuff . My last MAC 45 was a ballistic missle ..this motor needs to be replicated !!!!!!

tru story...raced k&b's 10 years...those are ALL the parts i broke, 2 cranks (from that bad run of heat treating on the pro motor) and a rod from a 8701 that was doing low 60's at the time (they run best rite before they break)....i'll take the risk..its worth it

 

[moparbarn]

lennard, i have had the samme experience with k&b as you. ran them on all my .21 tunnels & mod vp's, & in riggers. broke 2 rods in 5 years. 1 was my fault, over revved a drum rotor ib on the bench. the engine on my sport .21 villain tunnel started acting strange the middle of last season. very finicky needle (not like that engine at all), had to prop down to get speed back. changed carb, tanks , lines & filters, entire fr. housing, crank & bearings, pto & bearings. nothing changed.... had good compression, never ate a plug or "hammered" one either, so i didn't look at the piston or sleeve. ran last 3 district races & the fall nats chasing the problem. after the season, i tore the engine all the way apart. the head button & the piston were DESTROYED!! you couldn't even tell where the combustion chamber started & the squish band ended. not detonation, but BIG hammer marks. nothing missing from inside the engine, something went in the intake, i'm guessing. i was amazed that this thing even started, much less ran 4 complete race weekends + testing. they can be tough little engines. i'll post pics later, i think some of you guys that saw this boat run the last half of last season will be amazed.

 

[Lennard Cuenco]

lennard, i have had the samme experience with k&b as you. ran them on all my .21 tunnels & mod vp's, & in riggers. broke 2 rods in 5 years. 1 was my fault, over revved a drum rotor ib on the bench. the engine on my sport .21 villain tunnel started acting strange the middle of last season. very finicky needle (not like that engine at all), had to prop down to get speed back. changed carb, tanks , lines & filters, entire fr. housing, crank & bearings, pto & bearings. nothing changed.... had good compression, never ate a plug or "hammered" one either, so i didn't look at the piston or sleeve. ran last 3 district races & the fall nats chasing the problem. after the season, i tore the engine all the way apart. the head button & the piston were DESTROYED!! you couldn't even tell where the combustion chamber started & the squish band ended. not detonation, but BIG hammer marks. nothing missing from inside the engine, something went in the intake, i'm guessing. i was amazed that this thing even started, much less ran 4 complete race weekends + testing. they can be tough little engines. i'll post pics later, i think some of you guys that saw this boat run the last half of last season will be amazed.

those cranks broke the first time i ran the motors, interesting if you look closely at the picture,they both broke in the same exact spot, check the shape of the line at the bottom of the window..LOL

i knew that rod was sloppy around the crankpin before it let go...but i couldnt change it, motor was running so strong i didnt want to dis-assemble the piston/liner...i chose to break it...er, took the risk

when i first started boating, my boats were radared going 41 mph, then i met jack garcia (Vern), the radar readings went to the high 50's/low 60's after he taught me how to setup boats/motors, helped me win the championship...

i miss him terribly, he was my best bud in model boating

 

[Norm Doerr]

I ran Kabooms for a long time...they are like a Monkey on your back.. As soon as you say you are going to buy just one more.. before you know it.. you have a five gallon bucket full of parts. They are not bad to get in the water and start out with.. BUT don't expect to have one forever.

After you get about 12 of them there are enough parts to make three good ones. LIners come out of round, rods are not perfect in many ways, cases are weak etc. etc. If you run the large pin crank you bust the rod, if you run the small pin crank that shears off... I preferred the small pin crank,,, less damage than busting a rod and windowing the case. If you turn them much over 27,000 they get unhappy.. Kaboom!

Bill/ Andy ...That was the ugly red Hawk I had. The sponsons were VERY disposable and it ran VERY high and dry on the water.. Weighed about 5.5 pounds ran low to mid 70s turned pretty good..It was a fun boat for a while. Bill pitted for me the last race I ran with it.. I think we place second over all for the event. I remember that thing waving at us on the straight more than once. The entire time I kept it on the rich side so we did not have to switch engines.

Norm Doerr