gc160 carb manifold

[Minimichael]

Well I was wrong the first time about your needle position, so I don't know if you should trust me. But if I had to guess I'd say turn it out a hair. Maybe two. There's a Mikuni tuning manual floating around here. It gives a good lesson in the concepts of what all's going on in there.

 

[kidgambit]

Well I was wrong the first time about your needle position, so I don't know if you should trust me. But if I had to guess I'd say turn it out a hair. Maybe two. There's a Mikuni tuning manual floating around here. It gives a good lesson in the concepts of what all's going on in there.

I'm all new to this and any advice is greatly appreciated

 

[Harquebus]

so torque converter is on. but having a tuning issue.

This thread needs more pics.

 

[kidgambit]

I hope these help

 

[Minimichael]

Lookin' good man. Don't give up. You've come this far and that's a great engine and carb combo. This manual helped me.

 

[kidgambit]

I not giving up. I do need to figure out a new carb manifold for it. I need a angled one away from the torque converter

 

[Minimichael]

I not giving up. I do need to figure out a new carb manifold for it. I need a angled one away from the torque converter

How about a longer manifold hose? One with a turn in it.

 

[sparkwizard]

A large r rear sprocket might help with your bogging issue, too. That looks like it is ready for the highway.

 

[Skipp]

Best and simplest mikuni tuning video

 

[Skipp]

It’s a process…it may take days…different jets, different needle positions…on a built motor I even needed a different slide…some think this is a slap and go….good luck

 

[Skipp]

Now if your using a Chinese carb…especially the common 2547 I believe the number to be, the air mix is back by the flange and this happens to be the most suck ass carb on the market, and if you have one beat it with a hammer…

 

[sparkwizard]

That was simple and to the point.

 

[Harquebus]

I hope these help

Thanks. If anything, I really like seeing these engines on minibikes, they look 'proper'. They're my favorite non-vintage engine.

 

[sparkwizard]

I have one, but I haven't found a fitting, upswept "scrambler" type pipe for it yet, so I sits on a shelf.
I have often wondered how one of these OHC engines would rev up with the proper valve springs and exhaust.

 

[kidgambit]

so I ordered a curved manifold I will modify and have a friend weld back together

 

[Harquebus]

I haven't found a fitting, upswept "scrambler" type pipe for it yet

I'd love one from one of those plentiful clone-engine header makers but maybe this is (just as) viable:
https://www.oldminibikes.com/forum/index.php?threads/gc160-header-pipe.94624/

It's a lot more involved than the simple L bend headers for the clones. That more graceful, gradual 180° turn at the front, not anything sharp, seems about right.

Valve springs too, in the above thread.

 

[kidgambit]

I ordered a header on amazon

 

[DaddyJohn]

A large r rear sprocket might help with your bogging issue, too. That looks like it is ready for the highway.

I agree, the gearing for this will be way too tall with such a small rear sprocket and the big wheels. The Sears bikes with the bigger wheels had a jackshaft from the factory to reduce the gear ratio to something reasonable.

 

[kidgambit]

I am running a torque converter on it. but I did fix the pulling. the torque converter needs fress molly dry Lube. but the air fuel mixture screw didn't seem to help

 

[Minimichael]

Can you post a video demonstrating the problem? Maybe update where you're at? Might want to wait for the convertor install.