Abby's Guide to Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more)
Username Password
Discussions Reviews More Guides
Abby’s Guide > Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) > Discussions > Help with Carburetor Cleaning

Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Search For:
nibbler


Joined: Mar 5, 2004
Points: 751

Help with Carburetor Cleaning
Original Message   Feb 6, 2008 8:02 pm
One of my neighbours just gave me his lightly used Sears 10/28 snowblower. He is physically unable to use it any more and was having problems with it for the last couple of years. I suspect the main problem was lack of use and old gas. The machine looks practically new and is very clean. Its in better overall shape than my machine. The only two things I've found missing are the knob on the gear shift and the bolt that holds the top of the tube that the oil dip stick goes into. The engine would not start when I got it.

I took the cowling off and low and behold, the end of the tube from the primer bulb was frayed at the carburetor end. I cut off about 1/4" and put it back on. I've bought a new tube and will replace the old one as soon as it stops snowing and the sun comes out.

The engine starts up but now surges. I've put some Sea Foam into the gas and let it run for about 10 minutes. The engine is running better and does perform better under load. It still needs work.

According to what I've read from searches on this forum and on the Tecumseh Technician's Handbook for 3 to 11HP L-Head Engines the next thing is to take apart the carburetor and clean it. I've never done a carburetor disassembly, cleaning, rebuild before so any advice on cleaning agents, things to watch out for, errors in the handbook or any other advice people would care to offer would be appreciated. I will be getting a carburetor kit from the local L&G since I'm positive gaskets and O-rings need to be replaced.

I don't have the engine serial number but will post it once the snow stops ( Thursday morning is the current prediction).

If I still have a problem then it will be time to look at the governor.
Replies: 16 - 20 of 20Next page of topicsPreviousAllView as Outline
nibbler


Joined: Mar 5, 2004
Points: 751

Some Success
Reply #16   Mar 14, 2008 9:43 pm
I looked at the Tecumseh manual again and found the following things have happened:
  1. As I suspected the manual throttle plate that one of the rods to the governor connects to is supposed to be up and not down.
  2. I've used a dremel tool to cut a slot in the remainder of the broken machine screw. Is still stuck and the slot is starting to deform. I'm not sure if heating the unit will help but the only other solution is to drill it out and tap the hole;
  3. I have now got the correct sized O-ring installed on the fuel cup;
  4. When the throttle was set to "Fast" the engine would rev way to high. In fact oil was starting to come out of the breather tube. I repositioned the governor lever and it now runs better. I have to get a tachometer to set the correct high speed RPM but we are now in the ball park.
  5. Gas still leaks out if I'm not running the engine. I think the inlet seat needs to be reinstalled, I suspect its askew;
  6. I haven't figured out what is wrong with the idle adjust screw. there is a small brass washer on it outside of the O-ring. The washer isn't fixed to anything, isn't pressing against the o-ring and moves back and forth along the shaft. I did find one diagram for a different type of carburetor that showed a spring between the head of the screw and the brass washer. The spring pressed the washer against the o-ring. I also noticed that when I prime thee appears to be a misty jet coming out of that area. I will reread the installation instructions.
borat


Joined: Nov 10, 2007
Points: 2692

Re: Help with Carburetor Cleaning
Reply #17   Mar 14, 2008 11:37 pm
 Not to be a smart ass but you had me laughing for a while there. 

 I admire your perseverance and patience. 

However,personally, I'd have tossed that carb into orbit and bought a new one by now.

Good luck to you and thanks for the updates. 

nibbler


Joined: Mar 5, 2004
Points: 751

Re: Help with Carburetor Cleaning
Reply #18   Mar 16, 2008 1:13 am
No probs.

As to why I haven't gotten a new one:
  1. This is the first time I have done a carburetor cleaning, its a learning experience and therefore perseverance is the name of the game, I have to learn from my mistakes;
  2. I an cheap.
  3. This is for the "spare" snowblower, I can afford to have it out of service while I "play".
As far as I can see most have my problems are from inexperience and a fair bit of dumb luck.

I am learning and thats the main reason for posting, so people can learn from my mistakes, giving then a good laugh is an added bonus.
This message was modified Mar 16, 2008 by nibbler
Moderator Denis


Location: CAN
Joined:
Points: 638

Re: Help with Carburetor Cleaning
Reply #19   Mar 16, 2008 1:34 am
borat wrote:
I just finished cleaning and rebuilding my two Mikunis.  Lots of little parts to clean and replace (in this case).  One picture shows the shiny new replacement parts and the not so clean original parts.  The other shot is of the 32 year old carbs all cleaned up, re-assembled and pretty much ready to go..

   

Borat, I remember in 1973, I owned a Kawasaki semi-trail 90cc, that cames a with a mikunis carburator, very good quality, they really never gum out, well to say the truth, the engine never stops running hehehehe I was 14 years old you imagine, gas at that time was

49.9 cents a gallon :)) Yep Mikunis the only thing is on to 2 stroke engine vibration is present and going down and up pit sand the mikunis got easy disajusted, You are using 2 mikunis parallel :)) keep a flat screwdriver under seat you may need it, buy the way you are doing a pretty nice clean job on it, congradulation

This message was modified Mar 16, 2008 by Denis



borat


Joined: Nov 10, 2007
Points: 2692

Re: Help with Carburetor Cleaning
Reply #20   Mar 16, 2008 2:35 pm
Thanks Denis.

The Yamaha RD's are hot rod street bikes from the early 1970s.  The twins run pretty smooth compared to the small single Kawasaki you were riding.  The Mikuni VM28s hold their adjustment very well.  The idle screw and air screws both are spring loaded and don't move much.  They are the only two adjustment screws on the carbs.  I'm presently working on converting the points ignition system to an all electronic system.   I will also be installing a special CDI that I can plug a hand held controller into for adjusting the engine timing while the engine is running.  The programmer can hold up to ten programmed timing curves depending on what type of riding you want to do.  If you want to run with high fuel efficiency and cooler engine, there's a timing curve for that.  If you want all out horse power (for short durations) there's a curve for that.  Two stroke engines are sensitive to timing changes.  The timing requirements are considerably different at 3000 rpm vs. 10000 rpm.  Points ignition cannot deliver the timing performance that a electronic dynamic system can. 

I'm still a few weeks away from having the RD400 ready.  Will post some pics when it's ready. 

Replies: 16 - 20 of 20Next page of topicsPreviousAllView as Outline
Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Guide   •   Discussions  Reviews  
AbbysGuide.com   About Us   Terms of Use   Privacy Policy   Contact Us
Copyright 1998-2024 AbbysGuide.com. All rights reserved.
Site by Take 42