tohatsu 3.5 won't run without choking - Page 3 - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #21 of 65 Old 03-22-2008
Wharf Rat
 
bob chaisson's Avatar
 
Join Date: Mar 2006
Location: RI
Posts: 64
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
I had the same problem with my Tohatsu 8Hp. It was the ethanol clogging my jets. Had to clean the carb and used additive after that. If you can find any 100 octane racing fuel (ethanol free) run a tank of that, it will clean out the carb. Use additive after that, if your gas is going to sit for a week or more. Personally, I think your better of using it all the time.

Bob C s/v Valkyrie, Irwin Citation 35.5

One hand for the helm, one elbow for yourself!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
bob chaisson is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #22 of 65 Old 03-24-2008
Misanthrope
 
TohatsuGuru's Avatar
 
Join Date: Oct 2007
Location: Tampa
Posts: 115
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Service manuals for each brand are available from their respective dealers. The generic manuals often have errors and fail to address some aspects of repair on individual models. Clean the carb by taking it apart and soaking the appropriate pieces in carburetor cleaner. Nothing you can spray into it will dissolve the plugged jets and ports. Spray cleaners should be looked at as a preventive maintenance item rather than as a repair tool.

Elvin
Solution One Maritime
TohatsuGuru is offline  
Quote Quick Reply Share with Facebook
post #23 of 65 Old 03-25-2008
Senior Member
 
Omatako's Avatar
 
Join Date: Sep 2003
Location: Auckland New Zealand
Posts: 2,609
Thanks: 1
Thanked 34 Times in 31 Posts
Rep Power: 13
 
I haven't read the whole post yet . . . .

. . . . so I hope I'm not wasting your time.

Quote:
Originally Posted by ysabelsdad View Post
I have a 5 horse Mercury that is doing something very similar. Can anyone recommend a decent book on maintaining and repairing small outboards. Most of the book I have seen seem to be oriented to larger engines.
Try this site. It costs 15 odd dollars but I down-loaded the Mercury 1989 to 2000 manual and I'm really pleased with the result. This covers all models of Mercury from 2.2 hp to the big daddies.

Technical Download PDF / Text Suzuki GSXR 1000 Service Repair mercury

Andre
Omatako is offline  
Quote Quick Reply Share with Facebook
post #24 of 65 Old 03-25-2008
Senior Member
 
Omatako's Avatar
 
Join Date: Sep 2003
Location: Auckland New Zealand
Posts: 2,609
Thanks: 1
Thanked 34 Times in 31 Posts
Rep Power: 13
 
By now you have probably found the problem but here's a quick fix that often works for this type of problem.

Take off what you need to get to the inlet of the carb - run the engine up to a reasonably high RPM and then while holding the throttle open, block the airway (I try to use the palm of my hand).

The vacuum has to be drawn from somewhere and often it will draw bits of rubbish through the main jet and clear it. If it doesn't work, you haven't wasted too much time.

Andre
Omatako is offline  
Quote Quick Reply Share with Facebook
post #25 of 65 Old 08-21-2009
Junior Member
 
Join Date: Jun 2006
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Just found this thread the other day while trying to fix my friend's Tohatsu 3.5 2 stroke. What the problem turned out to be was the petcock was blocking the fuel flow to a few drops a minute when full open. Unable to disassemble it but there seems to a rubber washer or check valve that only allows fuel to flow in one direction. It was either gummed up or swollen from the ethanol and would allow just enough fuel to idle but not enough to get to half throttle.
Sprayed carb cleaner let it soak and blew it out with compressed air.
Motor now running better than it has in years
bb32 is offline  
Quote Quick Reply Share with Facebook
post #26 of 65 Old 08-21-2009
Member
 
Join Date: Aug 2009
Posts: 78
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
 
To avoid this problem

To avoid this problem in the future, if it is jet stopped up from crud, which I think you will find to be the cause. When you finish for the day with the engine, shut off the fuel and run the carb. dry. Modern?? gasoline is horrible, and while sta bil will keep it usable for some time, when it evaporates, still leaves junk behind, which stops up jets. Running it dry will eliminate this problem.

Dream like you will live forever. Live like you will die tomorrow. ( James Dean )
flatracker is offline  
Quote Quick Reply Share with Facebook
post #27 of 65 Old 08-22-2009
Senior Member
 
philsboat's Avatar
 
Join Date: Oct 2006
Location: Brockville,On.Ca.
Posts: 106
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
I found a tip from a motorcycle forum for dirty carbs.Buy a can of flammable carb cleaner.Drain out all of the gas from the motor.Put enough carb cleaner in the tank to run the engine.Start the engine and run until the carb is full of cleaner.(make sure the proper amount of oil is mixed with it if it's 2 cycle)Shut the engine off and let it sit for a day.Take it for a run with fresh gas and see what happens.
This saved the Triumph motorcycle owner $450 ($150)per carb.Costs $5 to $10 bucks.Make sure the cleaner is ok with plastic parts,it should be written on the label.

Phil
philsboat is offline  
Quote Quick Reply Share with Facebook
post #28 of 65 Old 08-23-2009
Misanthrope
 
TohatsuGuru's Avatar
 
Join Date: Oct 2007
Location: Tampa
Posts: 115
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
That's not a great idea. Most carburetor cleaners will dissolve the rubber and plastic components of the average carburetor. The only safe method is to remove the carb off of the engine, take it apart, dip the metal parts in carb cleaner for at least three hours, wash off, blow dry and re-assemble.

Elvin
Solution One Maritime
TohatsuGuru is offline  
Quote Quick Reply Share with Facebook
post #29 of 65 Old 08-24-2009
Cal 9.2 SilverSwan
 
roline's Avatar
 
Join Date: Jul 2000
Location: East Tennessee
Posts: 272
Thanks: 0
Thanked 2 Times in 1 Post
Rep Power: 16
 
I have a Johnson 3.5 internal tank on my 525, always shut the gas off, run the gas out of the carb, raise it and tilt it , place the sunbrella cover over the engine. I've done that for over 12 yrs. It starts on the third pull and runs strong. Try to find 100% gas, we just have a few stations that still sell it in our area. Only problem to date, watch out for the mub dobbers, they will make a nest in the strangest places like air cleaners or water exit tubes...

Cal 9.2 #19 SilverSwan
roline is offline  
Quote Quick Reply Share with Facebook
post #30 of 65 Old 08-24-2009
Learning the HARD way...
 
eherlihy's Avatar
 
Join Date: Jan 2007
Location: Boston / Ft Myers Area
Posts: 4,431
Thanks: 187
Thanked 123 Times in 120 Posts
Rep Power: 10
 
Mentioned elsewhere in this thread (and Sailnet) is the fact that alcohol (the 15% of E85) eats rubber. (try this experiment at home - pour some isopropyl alcohol into a dish, put a peice of black rubber - say a peice of an old windshield washer into the dish, let stand for 12 hours. Do you see any change in the rubber?)

The problem with this motor is most likeley that some rubber in the fuel supply (gasket, fuel or vacuum line) has partially dissolved and is either gumming up the carb, or causing a vacuum leak.

The FIX is to identify the damaged rubber component(s) and REPLACE it(them) - preferably with a like component that is not affected by alcohol. Rub a Q-Tip over suspect parts. If the cotton turns black, or gets little gooey black blobs on it, then you've found a problem. Then clean the rest of the fuel system (needle valve seats, venturi, jets, etc.).

The best preventitive measure is to run the motor dry, but then you may have to worry about corrosion. If this is a concern, then spray a can of motor fog into the carb before storing it.
eherlihy is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Nissan / Tohatsu 6h 4 stroke audeojude Outboard 261 09-08-2015 06:59 PM
New Dink, Looking at Tohatsu 3.5 Sapperwhite Gear & Maintenance 43 06-30-2009 07:38 AM
Make offer or run away? eherlihy Boat Review and Purchase Forum 56 10-03-2007 03:36 PM
Refrigeration—Part II Selecting a System Tom Wood Gear and Maintenance Articles 0 05-19-2003 09:00 PM
What to Do When You Run Aground Sue & Larry Her Sailnet Articles 0 12-18-2002 08:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome