I need a new Carburetor ( Robin Subaru 6.5hp)

[jamyers]

Jet sizes are hard/impossible to tell by eye, except that some are larger than others, lol. No telling if it'll need rejetting until you run it.

Looking forward to the movie!

 

[Najuto9tail]

Jet sizes are hard/impossible to tell by eye, except that some are larger than others, lol. No telling if it'll need rejetting until you run it.

Looking forward to the movie!

After lots of pulls for the pull start and tweaking the two screws I managed to turn it on, the engine started really accelerated and I made it go down for idle. The problem is that if I move the choke it will turn off...

I will upload videos in a while.

 

[Najuto9tail]

Sorry for using dropbox, my tablet does not wants to connect to my laptop do not know why...

I had to add a piece of fuel line with a screw on it to close the path of gasoline for the reserve on the shut off valve... because the gasoline was coming out from there.
https://www.dropbox.com/s/o2lo07js9tvrlkf/IMG_20130311_152044.jpg

The screws after some tweaking, the piece of fuel line, carb at different angle.
https://www.dropbox.com/s/pdwqyzmr3vmmw2r/IMG_20130311_152153.jpg

This video shows the engine when it turned off it got very hot on first start.
https://www.dropbox.com/s/swrax1zk6fj6or6/VID_20130311_150132.mp4

Edit- I am still uploading the videos of it turned on...

Here is a video of it turned on:
https://www.dropbox.com/s/h34dipwaqvogdzu/VID_20130311_170236.mp4

an other one:
https://www.dropbox.com/s/wt4f10z6lylx2bg/VID_20130311_170850.mp4

the last one:
https://www.dropbox.com/s/u0gdjws21diti4c/VID_20130311_171023.mp4

 

[Najuto9tail]

Jet sizes are hard/impossible to tell by eye, except that some are larger than others, lol. No telling if it'll need rejetting until you run it.

Looking forward to the movie!

The movies are available.

 

[jamyers]

The movies are available.

Looks good and sounds all right! Have you driven it yet? If so, how's it drive?

...The problem is that if I move the choke it will turn off...

Well, that's a problem...means that it's getting too much air from somewhere, either the idle mixture screw or you've got an air/vacuum leak. I'd suspect an air leak somewhere around the carb-to-engine, just because that's a non-stock carb mated up, and I've seen too many of these "leaning-cylinder" OHV engines try to hold the carb off from the intake with the sheet-metal shrouding...

You can check for an air/vacuum leak by spraying anything flammable on the carb/engine seam or anywhere there's a gasket - if there's a leak it'll suck the spray in and the idle speed will change up or down. OF COURSE, be careful spraying anything flammable around a hot engine, don't want to set your kart (or yourself) on fire, that would be bad...

 

[Najuto9tail]

Looks good and sounds all right! Have you driven it yet? If so, how's it drive?


Well, that's a problem...means that it's getting too much air from somewhere, either the idle mixture screw or you've got an air/vacuum leak.

I gave the nuts and screws a little bit of force to tighten then some more. I think I need to tweak the idle mix screw I do not know it making the screw come out a little will make it get more air o less. Have not run the kart yet, because one of the tires needs to be fixed... which I can fix with slime have to add some off it to the tire again, as I used to run it on the mountains where the trees branches that fell into the ground are from thorn trees. It is like getting nails on a tire...

Edit- the robin subaru original spacer had a paper gasket which broke easily when I removed it. Now it does not have any gasket at all. Just the spacer and the carb with the O ring and the gray silicone around it... did not used gray silicon where the spacer and engine intake contacts with... getting that carb out with those screws cutted will be a problem.

You know that the engine with the oem carb I had to run it with the choke on because it would turn off...
Same is happening with this one. What about running it like that will it be bad?

 

[jamyers]

...
You know that the engine with the oem carb I had to run it with the choke on because it would turn off...
Same is happening with this one. What about running it like that will it be bad?

It won't harm anything at idle, but you won't be able to put any kind of load on the engine, since the choke is cutting off a huge part of the airflow.

What it's telling you is that somewhere, somehow, too much air (relative to fuel) is getting into the engine. You really need to find the air leak if you're going to get more than 20% out of the engine.

EDIT: Regarding gaskets, a cereal-box cardboard gasket is going to be better than silicone - gasoline degrades silicone pretty quickly, and you can make a cereal-box gasket with some scissors and a good sharp blade (x-acto knife, etc).

If it was doing the same thing with another carb, I'd take a REALLY close look into the engine's intake port, making sure there aren't any cracks, etc.

EDIT 2: Where are you located? It'd be great if another board member was close by to come lend a helping hand...

 

[Najuto9tail]

It won't harm anything at idle, but you won't be able to put any kind of load on the engine, since the choke is cutting off a huge part of the airflow.

What it's telling you is that somewhere, somehow, too much air (relative to fuel) is getting into the engine. You really need to find the air leak if you're going to get more than 20% out of the engine.

EDIT: Regarding gaskets, a cereal-box cardboard gasket is going to be better than silicone - gasoline degrades silicone pretty quickly, and you can make a cereal-box gasket with some scissors and a good sharp blade (x-acto knife, etc).

If it was doing the same thing with another carb, I'd take a REALLY close look into the engine's intake port, making sure there aren't any cracks, etc.

EDIT 2: Where are you located? It'd be great if another board member was close by to come lend a helping hand...

Hi, I am located at Lajas, Puerto Rico, USA. I managed to fix the problem... The spacer had cracks in the inside... I used high quality gray silicon for motors on it, I loosen the carbs screws a little bit and applyed the gray silicon with a flat head screw driver to the small space between spacer and intake.
Waited a while for it to dry a little and I tighten the carbs screws a lot more than last time until they did not tighten any more. Turn it on and moved the choke to off at the same time tweaking the idle mix screw until I got it to open completely the carb and no choke needed for it to keep the engine turned on. I got it to work perfect now.
I took a ride with my best friend and was very impress as it gave more power with both of us ridding on it than when I ran it with oem carb and me alone.
I took a video of me ridding it:
https://www.dropbox.com/s/ltvf3nszymsqqu5/VID_20130312_174331.mp4

 

[jamyers]

GREAT!!! Love the video, looks like now it's time to think of the next modification, lol.
Actually, now you can start playing with the needle and jets, read the spark plug and get the carb dialed right in....


Congrats on working through everything - gotta love a DIY success!

 

[Najuto9tail]

GREAT!!! Love the video, looks like now it's time to think of the next modification, lol.
Actually, now you can start playing with the needle and jets, read the spark plug and get the carb dialed right in....


Congrats on working through everything - gotta love a DIY success!

Next mod will be adding a better exhaust. Thanks for the help and replies. I took the risk of buying the ct70 carb and it worked.

 

[Najuto9tail]

GREAT!!! Love the video, looks like now it's time to think of the next modification, lol.
Actually, now you can start playing with the needle and jets, read the spark plug and get the carb dialed right in....


Congrats on working through everything - gotta love a DIY success!

Updates: I took the original carbs jet out and it is bigger than the one that came with the one I adapted to the engine. I replaced it and now the engine works awesome.

So for those who want to adapt this kind of carb without any fancy mods.
1- Remove governor
2- Install the Honda CT 70 carb which is 19mm intake and 42mm bolt holes. To make it fit the choke hand must be removed leave the round piece alone, and the shutoff valve must be rotated to the oposite side. Get some fuel line about 2 feet aprox. A small piece of it will be adapted to the shutoff valve reserve with a screw or something that will stop gasoline from coming out of it.
3- Replace Jet with the OEM Robins Jet. ( If you want it to work great) Update(4/14/13): I used a very small drill to enlarge the jet hole so engine gets more gas, I will change the exhaust to a candy cane pipe.

This is what I did and it works great.