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  #1  
Old 03-31-2019, 04:39 PM
tango tango is offline
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Default Bombi carb

Hi guys, I recently bought a bombi and working on getting it fixed up. I had to replace the throttle cable. With out throttle cable installed With the machine not running and you manually open throttle wide open the butterfly inside the carburetor only opens about 15-20% is that normal on these. Most carbs I have been around the butterfly opens all the way from horizons to vertical. This also has the handy governed mounted below carb on top of manifold. Just want to figure this out before moving on thanks.
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Old 03-31-2019, 05:28 PM
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Default Re: Bombi carb

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Originally Posted by tango View Post
Hi guys, I recently bought a bombi and working on getting it fixed up. I had to replace the throttle cable. With out throttle cable installed With the machine not running and you manually open throttle wide open the butterfly inside the carburetor only opens about 15-20% is that normal on these. Most carbs I have been around the butterfly opens all the way from horizons to vertical. This also has the handy governed mounted below carb on top of manifold. Just want to figure this out before moving on thanks.
Thatís not normal it should open more than that
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Old 03-31-2019, 10:05 PM
Bobcatbob Bobcatbob is offline
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Default Re: Bombi carb

I recently had the carb off my Bombi replacing the diaphram. The butterfly should open to at least a 45 degree angle. Check the alignment between the hoof govenor and the carburetor.....the barrels need to line up for the butterfly to open (loosen the two mating nuts and see if you have it lined up).





Bob
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Old 03-31-2019, 10:28 PM
tango tango is offline
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Default Re: Bombi carb

Thanks for the info. I will check that. It sure acts like something is not right. If I manually open the throttle the diaphragm pump arm just starts to push the diaphragm and stops. I can physically push the pump diaphragm with my finger another quarter inch or so. When I start to go up the smallest hill I power out but I find I pump the gas pedal a lot the power comes back.

Last edited by tango; 03-31-2019 at 10:40 PM. Reason: Spelling
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Old 03-31-2019, 11:14 PM
Bobcatbob Bobcatbob is offline
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Default Re: Bombi carb

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Originally Posted by tango View Post
Thanks for the info. I will check that. It sure acts like something is not right. If I manually open the throttle the diaphragm pump arm just starts to push the diaphragm and stops. I can physically push the pump diaphragm with my finger another quarter inch or so. When I start to go up the smallest hill I power out but I find I pump the gas pedal a lot the power comes back.

Thatís exactly the problem I had. I replaced the fuel filter, then the diaphram (an Autolite 1250 carb rebuild kit will have the correct diaphram). Fuel filter had crap in it....and the diaphram was like vulcanized rubber. Once I did those two things, ran like a champ (now Iím doing a full restoration on the machine....rust was winning).

If those donít work (after making sure butterfly clears hoof governor opening), check your fuel pump, then fuel spray in carburetor.

Bob
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Old 03-31-2019, 11:29 PM
tango tango is offline
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Default Re: Bombi carb

When I do open the throttle as far as it will go it does move the diaphragm plunger just slightly and it sprays gas but not a lot. The machine is up at the cabin 100 miles away so wonít get a chance to work on it for a week or so.
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  #7  
Old 03-31-2019, 11:31 PM
tango tango is offline
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Default Re: Bombi carb

I know it’s hard to see top pict has butterfly closed second pict is wide open throttle but you can see the butterfly hardly moved.
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Old 03-31-2019, 11:42 PM
Bobcatbob Bobcatbob is offline
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Default Re: Bombi carb

Yep.....looks blocked (or linkage has play in it). Let us know how it turned out.

If the carb hasnít been rebuilt in years, consider a new diaphram (my old one had pin holes and was leaking)....possibly gaskets as well. I couldnít find a manual on this particular carb (they were made by ford for the Kent engine), otherwise I would have rebuilt it.

Bob
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Old 04-03-2019, 11:45 AM
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Default Re: Bombi carb

When the carb is on the table does the butter fly open .?
As for the governor I remove them and make a block or remove the butterfly and make sure it’s sealed around the gasket on the side plate they like sucking air
I install a tachometer and red line 5 grand on all the ones I restored
Have fun
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Old 04-03-2019, 06:50 PM
tango tango is offline
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Default Re: Bombi carb

Thanks for all the good info. I haven’t had a chance to pull carb yet to see if butterfly is hitting like bobcatbob had mentioned. Is it much of a job to take off the governer not really sure how’s those work. I wish I had it here in my shop instead at the cabin. I can’t wait to start tinkering on this unit.
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Old 04-06-2019, 06:15 PM
tango tango is offline
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Default Re: Bombi carb

Ok guys, I hauled bombi home and here is what Iím finding. I loosened the carb up moved it around a little bit working the throttle linkage by hand trying to get it to open up like bobcatbob suggested but had no luck. I than pulled the carburetor off and found the hole in the governer is square and smaller than the butterfly. That is why you canít open up the butterfly. With carburetor mounted at full throttle butterfly is open less than 10%. With carburetor off and open the throttle with linkage butterfly opens to 90 degrees of carb. The butterfly is slightly bent from hitting govenerrbase from operator pushing on pedal trying to get it to open up. Is that the way there made? I have never seen anything like this before. I lifted the governer up slightly off manifold and manifold has round hole same as carburetor. I will post a few pictures. I sure could use some input on this thanks all. First picture carb off butterfly all the way open. Second picture is if carb was mounted this is all the further butterfly will open. Third picture is square hole on top of govener. Thanks. Name:  CAAA692E-B7F5-482A-8523-4638D1016F8E.jpg
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Last edited by tango; 04-06-2019 at 06:38 PM. Reason: Added pictures
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  #12  
Old 04-06-2019, 06:48 PM
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Default Re: Bombi carb

Get a block made is what I would do. Make it out of aluminum if you find a 1Ē
Piece you can make it yourself. Hole saw use WD40 to keep the teeth clean
The machine will run way better .the thing that someone put in there is wrong
They had a round hole in all the ones I took out
Have fun
I was out yesterday lots of snow in the bush
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Old 04-06-2019, 06:50 PM
snowcatt snowcatt is offline
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Default Re: Bombi carb

Take the butterfly out and use a die grinder and open the hole up to the carb size
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Old 04-06-2019, 07:14 PM
tango tango is offline
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Default Re: Bombi carb

Think I will take governer off and open up the square hole to match carburetor. I have a big mill and boring bars to do this. Just didn’t want to screw governer up if this was in fact the way it was designed to work. I didn’t want to bore it out then find out that it was correct and have to look for new governer. Thanks
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Old 04-06-2019, 10:47 PM
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Default Re: Bombi carb

If you do totally disable it which seems like the best thing to do you can add an electronic rev limiter to prevent overspeeding the engine.
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Old 04-07-2019, 11:39 AM
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Default Re: Bombi carb

Looks like air leak below gasket where the notch is in the carb? No seal.
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Old 04-07-2019, 11:45 AM
snowcatt snowcatt is offline
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Default Re: Bombi carb

What Iíve been doing is taking out the hour meter and putting in a digital 2Ē
Tachometer in the hole with a 5 grand red line
Good luck have fun
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Old 04-07-2019, 01:44 PM
tango tango is offline
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Default Re: Bombi carb

Good catch on the notch on bottom of carb sucking air. I will put on new gaskets of course and check those notches and see if those are cut all the way through. There is already a tach mounted in it but I will replace with a new one. With governer on as normal the most RPMs I could get was 2200. That is why I started digging into this thing The gentleman I bought this from had it 5 years but never used it. Surely at some point this thing had to open up more than this but I don’t see how with that square hole governer I’m sure this bombi project will turn into a all summer project. Thanks for all the good advice
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Old 04-21-2019, 01:08 PM
tango tango is offline
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Default Re: Bombi carb

I have machined out a new piece of aluminum to put where that governer was. It fits perfect. Straightened the throttle butterfly put it all back together and it literally doubled or more the horse power and response time of machine. Snow is about gone so I parked in shop and going to do a complete tear done to inspect and see what else I can find and give it a paint job. I’m looking for new louvers for engine cover are they available any where? Thanks
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Old 04-23-2019, 10:08 PM
snowcatt snowcatt is offline
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Default Re: Bombi carb

There hard to find in good shape which ones do you need .ill check and see what I have
I’ve made them out of metal it’s not that hard
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