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Fly Tying
Mark Knapp

What are you working on?

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My apologies, but jet drives are a rarity in my experiences. I know those specifications are important enough to have relatively close tolerances.

I am not sure the differences you've noted would result in cutting your thrust by half! If you do not see a return to previous values after re-shimming ... I can see if any of the other instructors have more experience with such things.

 

Good luck, my friend.

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As I get older I'm trying to avoid anything with a motor if possible- I've spent way to many valuable hours turning wrenches.

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Working on the boat all weekend. Put fuel injection in my 460 Ford marine engine in the 24 foot Almar jet boat. It's been a struggle to get it running right ever since. But, you know what "BOAT" stands for..... "Break Out Another Thousand".

Well I'll be working on my boat again this weekend. After changing the plugs and shimming the impeller I took it out for a ride today. My RPM's dropped a few hundred at WOT so I changed the plugs. All good there as I'm back to 5800 RPMs at WOT.

 

My impeller is another story. Between the impeller and the liner it was gapped out at .028. Service manual calls for somewhere a range between .020 and .030. I moved one shim from front to back. With each shim being .007 my gap was now set to about .021. I was shocked to see my propulsion cut almost in half even with my RPMs back to normal. I can't believe a .007 difference could cause such a propulsion drop. Now my original three bladed impeller was replaced with a four blade stainless impeller so maybe the tolerance between it and the liner is different. I'm going to move the shim back to where it was and see what happens.

 

Any thoughts MChell?

 

Boats, or more specifically the engines, are ridiculous, contrary things, like donkeys or women. But..... if you need a donkey, you need a donkey.

 

Part of my problem boiled down to a broken off oil pick-up tube for the oil pump. It required pulling the engine and dropping the oil pan to fix the problem. Three days later I got it all back together and It runs much better but I still can't get the RPM's over 2600. We muddle on.

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I'm just going to say it, I'M AN IDIOT!! I should just quietly say I fixed the problem of a lack of thrust on my motor but what the hell, this isn't the only dumb thing I've done in my life and if history does in fact repeat itself it won't be the last. I went to unfix the shim that I thought was possibly the cause of the problem. It took me about 1 second to realize I put the foot on backwards. How I didn't notice this when I put it on I'll never know. What a dumbass.

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Oh ... mellow.png ... that doesn't make you an idiot ... dry.png ... It's a mistake anyone could've made ... rolleyes.gif ...

 

It's unsure.png not happy.png funny tongue.png at all !! laugh.png biggrin.png laugh.png biggrin.png laugh.png biggrin.png laugh.png biggrin.png laugh.png

 

Thanks for the honesty on this one. I needed a break. My group (of students this week) has no sense of humor. It's been a long week.

 

Glad to hear, though, that it was such an easy fix!!!

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I've taken this foot off and put it back on a hundred times. This was a first. At least I was right in not beleiving a .007 shim could reduce HP that much.

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I've taken this foot off and put it back on a hundred times. This was a first. At least I was right in not beleiving a .007 shim could reduce HP that much.

I wish I could fix my boat problem as easily. It's probably something easy and stupid but I've already spent way too much money trying to fix it.

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I've always found RPM problems to be simple fixes like fuel line bulbs, gas tank vents, spark plugs, something in the fuel delivery. Perhaps bigger jets.

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Finally back on the water again, the start of a six day booking. Of course my brand new motor quit on us within the first four miles so that was the end of that. Back to the ramp, a long run to my dealer... Now my new motor has a new fuel pump and they swear Im good to go. My anglers will find out tomorrow... Now Im down to a five day booking.

 

Arent boats fun?

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I've always found RPM problems to be simple fixes like fuel line bulbs, gas tank vents, spark plugs, something in the fuel delivery. Perhaps bigger jets.

In my case, I had a perfectly good running boat but, being a Ford 460 inboard jet, it had horrible fuel economy (30 gals. an hour at WOT) My boat/auto mechanic suggested I put in Multi-port EFI to remedy the economy problem so I ordered the parts and had him install them. It hasn't run well since. I've got a crew of smart people to help me fix it but right now I'm waiting for moose season to get over with so that they can all get home and we can get back to work on it.

 

Around here, when moose season comes, everything else comes to a screeching halt. I don't blame them though I went moose hunting too.

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Of course my brand new motor quit on us within the first four miles so that was the end of that.

Four strokes are looking pretty good about now, huh? dry.png

Sorry ... had to throw that in there! biggrin.png

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A week or so ago I got some really neat feathers, some Argus pheasant feathers. I bought them for eye balls on big streamers for ling cod and halibut. I've been playing with some designs with died mt. goat and Lady Amherst's Pheasant feathers. These are all about 8 inches long and tied with 6/0, 7/0 and 9/0 hooks.

 

I'm leaving for an eight day fly fishing trip in about a week to try them out and here they are.

 

DSCF4120-X2.jpg

 

DSCF4115-X2.jpg

 

DSCF4114-X2.jpg

 

DSCF4125-XL.jpg

 

DSCF4121-X2.jpg

 

DSCF4126-XL.jpg

 

I'll let you know how they do. Now I've got to tie up a bunch of leaders.

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