1957 Fastwin 18 Revving out

[WEIGLE]

First of all, THANK YOU ALL so much for your help throughout the past. Without your resource of knowledge this motor would never keep on chugging along.

I have noticed that a few times when I pull my '57 Fastwin 18hp (150220) out of the water and tilt it over while on shore for several hours that SOMETIMES when I get back on the water and try to reach top-speed the engine will rev-out like air is getting to the prop.

I can only achieve 3/4 throttle before it happens, and then it idles rough and never seems to correct itself, but won't happen next time I launch the boat. Is the motor getting flooded when it's tilted up and over as wakes rock the boat? Any thoughts or fixes?

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

ttt

 

[nwcove]

Re: 1957 Fastwin 18 Revving out

do you still have the old pressure tank set up? if so do you let te pressure off when you're done for the day? it could be dropping the float when its tilted and allowing fuel past the seat under pressure? id doesnt sound like a flooding issue, but if you feel that it might be, that could cause it. sounds more like air under the hull.

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

I thought the same thing, air under the hull but I swerved left and right for over a mile then went in circles. . . nothing helped. I disconnect the pressure tank when not on the water but leave it hooked up when I am anchored. I don't suppose it would be stripped gears since it works fine until reaching a certain RPM? Then again, it ran like CRAP at idle but I've never heard of an engine revving out from being flooded, too rich, or too lean.

Such a simple motor, such a complicated problem.

 

[cc67]

Re: 1957 Fastwin 18 Revving out

Sounds like your prop hub is slipping under load.

 

[samo_ott]

Re: 1957 Fastwin 18 Revving out

I don't fully understand the problem here. It could be a slipping prop if it revs higher than 3/4ers with no speed gain but that would not account for a rough idle. Can you explain it more?

 

[1946Zephyr]

Re: 1957 Fastwin 18 Revving out

Check your needle jet settings. Should be 1 1/2 turns out on the slow speed and 3/4 turn out on the high speed.

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

Here is a video I took today on the water describing the problem. Listen carefully to the engine. After revving-out it will continue forward progress with extremely high RPMS but very slow speed.

http://www.youtube.com/watch?v=G08jCBchROE

 

[nwcove]

Re: 1957 Fastwin 18 Revving out

that is cavitation or more likely a spun hub. there is directions here....somewhere..on how to mark your hub, to see if it is slipping, that should confirm or rule out that problem. definitely not an engine issue.

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

After reading other threads on hub-spin, it sounds identical to what I am experiencing. Everything works fine until I speed up then it slips. When I stop and try again it works fine until I speed up again. Thank you all for the advice!

 

[mstahl1171]

Re: 1957 Fastwin 18 Revving out

Any good prop shop can fix. Did mine last year for under $50.00 If you can buy another prop as a spare and you'll always be in business while the other is being fixed

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

so if I buy a prop will it have all the guts inside or will I need to find some parts? Sounds too easy. I also saw the service bulletin advising against backing the nut off to align with the next cotter pin hole and to install by hand tightening, then take a wrench to turn the nut so that aligns with the closest cotter-pin hole. The bulletin stated that it was for 9.5, 20, and 25hp motors and was issued in 1972. Does it still apply to an 18hp '57?

here is a schematic of the prop area:
http://www.marineengine.com/parts/vintage-evinrude-johnson/ITEM_2833/ITEM_283300010im.jpg

And a $89 prop someone on here bought (looks like it was made in china):
http://www.tacomapropeller.com/6431...ers/9-X-10-RH-3-Blade-AL-Match-Propeller.html

 

[mstahl1171]

Re: 1957 Fastwin 18 Revving out

yeppers...all you need is the prop and I would install a new cotter key just to be safe. Take the old prop off and you'll see how easy it is. And no...that service bulletin does not apply to your motor.

 

[samo_ott]

Re: 1957 Fastwin 18 Revving out

Nice looking engine. And yep, it's a spun prop! Get a new prop!

 

[kfa4303]

Re: 1957 Fastwin 18 Revving out

First of all, great lookin' old evinrude. Does seem like a prop issue as the motor seems to be running and idling well otherwise. I guess the easiest way to confirm a spun prop is to make a level horizontal mark across the hub and prop, then get the motor up to speed under load and check the prop again to see if the line is still intact, level and even. It it has separated then you know for sure the hub is spun. The shuttering/vibrating could be due to vibrations being sent through the leg of the motor and into the transom/hull due to the spun prop. Thankfully, the props really are amazingly cheap/easy to replace too. They seem to be readily available on sites like ebay. iboats probably sells them too. You might get lucky with a donor motor's prop too. Gotta love the old OMCs. Good luck. Keep us posted.

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out

Y'all were right, it was a spun prop. I put a new one on from
Michigan Wheel (bought on iboats) and it runs perfect. I took a 9.25 x 11 off so that's what I put back on versus a stock 9 x 10. I also replaced the J-6J plugs with J4C's. Yes, that's correct... I REMOVED the impossible-to-find J-6J plugs.

She runs BEAUTIFULLY now (even a little faster) but I accidently cross-threaded the spark plug on the first 3 threads so I am looking for a new OMC or like new head and head gasket.

I LOVE this motor. It's so easy to work on and parts are "fairly" easy to buy and
at low prices. OMC did well by using the same parts year after year which helps locate them.

Know where I can buy a head? Should I replace anything else while it's off?

Thank you all again! I love iBoats!!

 

[WEIGLE]

Re: 1957 Fastwin 18 Revving out -- SOLVED

Re: 1957 Fastwin 18 Revving out -- SOLVED

Y'all were right, it was a spun prop. I put a new one on from
Michigan Wheel (bought on iboats) and it runs perfect. I took a 9.25 x 11 off so that's what I put back on versus a stock 9 x 10. I also replaced the J-6J plugs with J4C's. Yes, that's correct... I REMOVED the impossible-to-find J-6J plugs.

She runs BEAUTIFULLY now (even a little faster) but I accidently cross-threaded the spark plug on the first 3 threads so I am looking for a new OMC or like new head and head gasket.

I LOVE this motor. It's so easy to work on and parts are "fairly" easy to buy and
at low prices. OMC did well by using the same parts year after year which helps locate them.

Know where I can buy a head? Should I replace anything else while it's off?

Thank you all again! I love iBoats!!

 

[wilde1j]

Re: 1957 Fastwin 18 Revving out -- SOLVED

Re: 1957 Fastwin 18 Revving out -- SOLVED

See salvage yards

http://forums.iboats.com/showthread.php?t=299680

 

[mstahl1171]

Re: 1957 Fastwin 18 Revving out -- SOLVED

Re: 1957 Fastwin 18 Revving out -- SOLVED

You can have a heli-coil installed to solve your crossthread issue. If you want a new head just do a search on ebay...im sure there is some out there. New head gasket you can try Fairwinds Marina (410) 974-0758 in Annapolis...they should have what your looking for. Heck...they might have a new head also....

 

[kfa4303]

Re: 1957 Fastwin 18 Revving out -- SOLVED

Re: 1957 Fastwin 18 Revving out -- SOLVED

ditto on the helicoil. there should be some threads on how to install it. if you want a new head, I think good 'ol ebay is a great place to start. glad you got her going again. happy boating.