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Vintage Fastwin 18 HP Carburator Issues.

M

memiker

Member
Hi

This is my first post -- but I have been using the information from the site for some time.

Many thanks to the contributing members for the time and energy you have saved me with your expertise.

My current project is a vintage Fastwin 18 HP -- it has no tag but I believe it is a 1957 model.
It has been in our family for many years - my oldest kid used it on his first boat, a 13 foot whaler - more than three decades ago. He stored it all these years and now I am restoring it for use on a 16' Classic PET Skiff. I have both long and short shafts and about six different props. *

I put a seal kit on the lower unit and "almost" stopped the water intrusion. The prop shaft is grooved at the seal surface. I found a new prop shaft at Sea-Way Marine -- I haven't installed it yet.

I also installed a carb kit. It was running very rough on the initial kit. I repaired the threaded bushing that was loose in the casting at the high speed jet. I found a replacement float bowl with a redesigned high speed needle setup - sold as a kit -- also at Sea-Way. I installed it thinking the threaded bushing was not correctly positioned or secured by my my repair work.

Now it barely stays running -- it starts when I set both jets according to the instructions in the kits -- but I can't get it smoothed out - at all. If anyone has a good method to get the carb adjusted correctly -- I could sure use some help. One last point -- before I replaced the float bowl -- I ran it on the boat -- it was surging very badly -- to the point where the pin sheared. I remember this motor seemed to shear the pins frequently under heavy loads. We had to baby it to full throttle.*

I plan to replace the points and condensers but I want make sure i don't compound problems -- I want it to start and run smoothly before replacing more parts. *

Thanks
 
I did a compression test when I started the project. If I remember correctly - 75-80 psi with both the same. There is compression in both cylinders and it does start up and run poorly. I have new plugs installed -- the sparks seems a bit weak to me -- but I don't know what to expect from this old magneto. I checked the point gaps - one needed a small adjustment. This didn't help any.
 
If it has been stored for 20 plus years, the ignition coils are probably cracked and leaking voltage...this can quickly be confirmed by removing the recoil and the three bolts which hold the starter ratchet and the inspection cover to the flywheel. This will allow you to examine the coils without removing the flywheel. The grease which lubricates the fiber rubbing block on the points has probably dried up and running the motor without the points being lubricated will result in the rubbing block wearing down and the point gap decreasing enough to cause a problem. If the ignition system is not working properly, you will never get the engine to run smooth regardless of how the carburetor is adjusted. The shear pin should not shear unless the prop hits something more solid than water....are you using the correct aluminum prop and the correct shear pin.
 
I have previously inspected the coils through the port as you suggested. No cracking is apparent. Can't see much else thru the hole -- I think I will pull the fly wheel, clean lube and adjust everything and try again. Is there anything tricky about removing this fly wheel ?
 
It might come off easy, it may not. Just remove the nut, install a puller using the three threaded holes for the recoil ratchet, and tighten the puller. A good crack with a hammer on the center puller bolt should loosen off the flywheel. If it doeshn't, tighen the puller some more, and let it sit overnight. Sometime that will work. I have 3 1958 Evinrudes, including an 18 hp that I have owned since 1978. Great motor, it sat in my garage (unheated) for about 15 years, and I fired it up last year with minimal work.

Good luck, keep us posted on your progress.
 
Forgot to mention the prop and sheer pins. I have no way to verify if any of the props I have are the original equipment. The one that's on there now seemed to work well back when. The slot etc on all the props are similar to each other.
I made the present pin from brass stock to match the one I found in there, because i couldn't find a replacement using the make and model information. It is a little undersize for the hole in the shaft. I could have matched the diameter of the hole -- but I was afraid of damaging gears in the event of impacting something. Do you know the correct pin specs? and where I can purchase some?
 
Well - after some delay, I am back with an update on the old Fastwin (57-58). I used too large a puller on the flywheel and damaged it. I was lucky to find a replacement on eBay -- and have installed new OEM breaker points and condensers and the replacement flywheel. I had previously rebuilt the carb and later replaced the float bowl with a new style kit. I am pleased to say it is running much better. Top end power is strong and low end idle is OK with one minor exception. Somehow I lost the throttle friction. I remember when doing the points - I wanted to remove the timing disc completely to inspect the parts under it. I loosened one screw and decided it the plate was not coming off easily. I put the screw back - but I think I may have screwed up the friction for the tiller handle.

Does anyone have a manual that covers the friction and throttle stop mechanism adjustments?

I need to get the throttle correct before fine tuning the carb adjustments.

A couple of other observations. I am see gas rainbows in the water with the fuel line connected and the boat tied to the dock for a time. I am thinking the cork float -- needs to be replaced. Any other ideas?

I stalled the motor during my testing and saw what looked like snow flakes in the water - coming from the exhaust ? I think I remember this phenomenon from years back -- or am I going Crazy? Anyone ever see anything like this?

The sheer pin breaking was caused by a combination of a wallowed out hole and the power surging. My home made sheer pins fit perfectly in my new prop shaft (not installed yet). I also replaced a few parts in the recoil starter. The top bolt was not an original part and the washer and pawl were worn. The new parts make it all operate smoothly and engage more reliably when you pull the cord.

Thanks again for all your assistance.

Mike R
 
What oil to gas ratio are you using??? Those older motors are not environmentally friendly and are even outlawed on some lakes...the rainbow may or may not be "Normal" The throttle friction is regulated with a nylon friction disc located under the twist grip handle. You can use the diagrams of your motor (available on this site) to see how the parts are laid out. The shear pins are available, cheap and of the correct consistency to shear without damaging the motor...the homemade versions may not shear as intended by the manufacturer. The "snow flakes" are probably aluminum residue which occurs after the motor has not run for awhile.
 
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