Jerry Dunlap!! Help!!

[JohnBoy]

Jerry, I have a few more questions maybe you can help me with.

1. Right now with the Pro carb on, the motor has hardly any power until it hits the pipe. It takes forever then half way down the straight it's flat out scary-speed. Will the smaller #9445 carb I bought make the power come on sooner?

2. My boat is very loose and sometimes it hits it's own wave and stuffs the bow when coming down. Will more weight in the back help this? It also barrel rolls occasionally if I corner at wide open how can I stop this?

Although I am buying a HTB-360 next month I am interested in getting this one handling better before it is retired.

Thanks for your thoughts, John Smith

 

[Jerry Dunlap]

John,

1. Regarding the power transition, I think the large bore carb is causing that condition.

2. Like I mentioned in a previous post, 32" is small for a 7.5 mod tunnel. You might try the following:

Run a smaller prop with less pitch. If I recall, you mentioned you could run something like a Prather 235. Well, that's a big prop with lots of pitch. You might want to try an Octura X447. That should allow the motor to "r-up" and not cause it to torque roll. Try running the c/l of the prop above the bottom of the sponsons - 1/8" or more.

I think you will fine the HTB 360 a much better platform for the 7.5 Pro.

Jerry D.

 

[not2bright]

jerry where do you live? i thoght you said something about seahawk country. if thats true or not i dont know but i am in the kitsap radio control boat club you might have raced with us

 

[Jerry Dunlap]

NTB,

Sure, I've raced at Sandy Shores. I'm planning to attend the NW Model Expo in Puyallup this weekend, say "hi" if you get down there.

JD

 

[JohnBoy]

Ok, Got parts from G&M. Carb bolted right on. Checked head clearance and it was .022. removed shim from head and it is only .017. How do I get it down to .008? Do I grind off some of the sleeve top?

Jerry how do you like the Keelie Water cooled head on your Pro? Is it worth the money?

Thanks, John S

 

[not2bright]

yah i was there saw your boat wow!!!!!!!!!!!!!!!! very nice i didnt see very much boat stuff very big dissapointment. i was looking for a 21 for my hydro but no cigar oh well better luck next year

 

[waterbug]

HEY, JOHN

I'm not a expert or a god on this forum BUT!

It seems to me that if you try to clamp the sleeve to grind it or turn it you run a risk of distorting the sleeve!

I would take the head and turn it in a lathe , take 9 or 10 thow. off and shim the head with a shim!!

Or if you must cut the sleeve, [ You say u have a automotive background ] , Go to the valve grinding machine ,to the valve stem grinder station , were you face the valve stem tip! Clean the v block were you clamp the stem, clamp it in just snug!! Turn the adjustment dial until it barely touches the sleeve face and 0 the dial, now turn the dial a .001 at a time till you take off what you want!! Just be sure the oiler is running on the sleeve! I think it's cheaper to buy a head than a sleeve!!!!!!

Hope it help's ;D ;D

 

[Jerry Dunlap]

John,

On the K&B 7.5 Pro, here's how I reduced the deck clearance. Using 400 grit wet/dry(wetter with WD 40) paper on a small mirror, I carefully sanded the top flange of the sleeve checking all the time with a mic on how much I was removing. The sleeve is moved in small circles with even pressure applied.

I think WB has some good suggestions also.

Jerry

 

[JohnBoy]

Thanks Jerry I will try the 400 with WD-40 on glass.

John S