FX-1 FX1 Runs Great - No Go - Help in Diagnose

kkosche

kkosche

Location
Lake Stevens, WA
I have an FX1, 144mm pump, stock shoe, 13/17 impeller, Factory Pipe, Rejetted / pop off SBN 44. Has ran fantastic all summer. 40 Gallons off fuel through it. Lots of fun, up until last night.

Jumping some waves, 10 minutes into my ride I jump a medium size wave, land, hit the throttle and Engine runs fine, no go forward. Shut it down (sitting in the middle of the lake, with lots of boat traffic / waves). Starts right back up. Zip the throttle a couple times. Sounds great, revs right up . . . ZERO forward motion. Swam it into the beach and now it is on a stand in my garage.

I removed the two bolts in the splash cover (rear of the motor) to see if I could see the couplers / rubber dampener. . . can't get a good angle w/mirror light. So no clues there. No visible trauma looking through the steering cone or up through the intake grate.

Need you FX1 experts to tell me what end to start on? Drop pump and look at shaft, splines, etc . . . or pull tank, battery tray, bilge switch, stinger, slide motor forward and look at coupler. Pump would be easier . . . but I don't want that to influence the unbiased logic you experts are about to give me . . and I would prefer not to have to pull apart both ends.

Thanks folks.
 
BruceSki

BruceSki

Formerly Motoman25
Location
Long Island
start the ski on the stand/trailer on dry land.

Check the couplers and make sure they are spinning at an idle.

Look under the ski through the intake grate and see if the driveshaft/prop are spinning.


It sounds like you stripped the driveshaft/midshaft to me but the above test will tell you what you did for sure. Do that and get back to us.
 
kkosche

kkosche

Location
Lake Stevens, WA
Hey now . . don't get too down on that 144 . . . I got too much money in mine. ;)

I put a wooden dowel through the steering nozzle and was able to spin the impeller w/o the drive shaft spinning. . . so I started on the Pump end.

Here is the picture of the problem.

Two questions:

1. How common is this problem (snapped FX1 drive shaft on a 144 pump). Looking a SJ shaft . . . it doesn't look any different (in diameter) just about 2" longer.

2. Anyone got a FX1 drive shaft to sell me so I can get back out on the water?

Thanks folks.

k
photo.JPG
 
kkosche

kkosche

Location
Lake Stevens, WA
Removing the impeller from such a situation is proving difficult. I now have a ez-out broken off in the end of the shaft that you see inside the impeller.

Heat and an impact driver didn't do it either. Now sitting with penetrating oil inside the impeller cone (filled it to the top) . . . more heat and impact tomorrow. If that doesn't solve it, I will consider sacrificing the pump section to save the impeller . . . or visa verse depending on what the corresponding parts cost.

Good times.

I would throw on a pict or two . . . but looks like I need to have a webspace to store them and then point a URL to them. Seems like a pain, unless I am just being dense.
 
kkosche

kkosche

Location
Lake Stevens, WA
MNTURBO said:
weld a nut on the end of the shaft - that will give you a place to hold the driveshaft steady

or send it off to a shop
Click to expand...

Shaft snapped right at the end of the impeller. I would blow away the thin edge of the impeller if I attempted to get any decent penetration with wire or arc. Shop? Humm. . . . turn around time an $$$ . . . going to work it a little more before throwing in the towel.
 
MNTURBO

MNTURBO

Location
Minneapolis, MN
kkosche said:
Shaft snapped right at the end of the impeller. I would blow away the thin edge of the impeller if I attempted to get any decent penetration with wire or arc. Shop? Humm. . . . turn around time an $$$ . . . going to work it a little more before throwing in the towel.
Click to expand...

what about welding the nut on the other side of the driveshaft?
 
kkosche

kkosche

Location
Lake Stevens, WA
MNTURBO said:
what about welding the nut on the other side of the driveshaft?
Click to expand...

Thats worth a try if I fail at the next round of impact. Only challenge on the other end of the drive shaft, is the shaft is hollow on that end. Not as much meat to get penetration on . . . but desperate times call for . . .

Maybe get a nut that is VERY large, so that it will slip over the threaded portion of the shaft. Then zip it with the welder around the entire inside perimeter. Since the shaft is pressed out from the impeller end . . . it wouldn't matter if there was something oversize on that end.

Thanks for the back up plan.

Would like to post pictures of this adventure . . . . how do most folks do it? URL and store elsewhere?

Thanks again.

k.
 
tnj4life

tnj4life

Location
Marshall, AR
driftmaster said:
One more reason.

You 144 guys are running out of shafts. Sorry but true. I would stock pile. ;)

Hope you get it going.
Click to expand...

Haha, ive thought about that. For every fx1 rider that shears a shaft thats one less out there, and since there were only a handful fx1s made as time progresses the fx driveshaft will become extinct. Maybe by then someone will step up and start manufacturing.
 
ADDict

ADDict

Had the exact thing happen a few weeks back.. Just found a nut that fit the threads on the back side of the pump, threaded it on, held it and broke the impeller loose. Easy fix actually..
 
kkosche

kkosche

Location
Lake Stevens, WA
I looked at using a Nut before I went to the impact. When I considered this, it appeared to me at least, that the nut would just unthread itself (threads going same direction as I need to torque the impeller) hence the need to weld the nut in place. Did I mis-read the threads, or did you also apply some weld love?

Also . . . you can still find FX1 shafts from Yamaha . . they are just expensive $300 ish. For me, I didn't want to cut my boat to install a bigger pump (kawi). . . and after listening to all the back / forth debates, the conclusion I came up with was that the 144 is larger, and of a more efficient design. Down side is the shaft.

http://en.wikipedia.org/wiki/Shot_peening

Has anyone considered (or actually tried) shot-peening the shaft (like the do with connecting rods on automobile motors) to relieve any stress areas on the shaft? I looked at cutting a new shaft out of stronger stock, but there be plenty of cuts between the two sets of threads, splines and bearing races. Not impossible, but time consuming . . . bet I could sell 100 shafts if I made them thou. ;)

Thanks again folks. I'll keep you posted.

Also, if anyone has an easy way to post some picts, all ears there too . . .
 
MNTURBO

MNTURBO

Location
Minneapolis, MN
Finding fx-1 shafts is not an issue, there is one for sale on the X right now, and 122mm fx1 pumps are cheap. Otherwise you could always buy a longer shaft and send it to someone to shorten to the fx-1 length
 
kkosche

kkosche

Location
Lake Stevens, WA
ADDict said:
Had the exact thing happen a few weeks back.. Just found a nut that fit the threads on the back side of the pump, threaded it on, held it and broke the impeller loose. Easy fix actually..
Click to expand...


Turns out I read the thread direction wrong. ADDict is spot on. Went to hardware store and got a 20mm 1.5mm pitch nut, went on put the impeller side down in a vice w/impeller tool viced, put a 1 3/16" wrench (close enough) and a breaker bar . . . applied as even heat as I could to thread sections of impeller and laid the wood to it. Got it apart and and I am am a shaft a way from being back on the water.

I still would like to know if anyone has tried shot peening a shaft to reduce stress. Also interested if anyone has shortened a SJ shaft to work. I think I will mic both a FX and SJ shaft to see if there is any diameter difference between the two. If the SJ is thicker . . . might be worth looking into re-spline (or extending existing splines). That would open up several thousand available shafts for such a set up.
 
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