Ridiculous carb problem T350

[cafe noob]

OK, I searched around and can find no answer to this… I just tore down my carbs (stock) and cleaned them, put them back on with a new throttle cable, and the bike revs through the roof when I crank it. I have the cables all the way loose, no even attached at the grip, and confirmed the slides are closed. Here's the tricky part… If I take the cables off of the carbs and change nothing else, the bike starts and idles perfectly, but as soon as the cables are back on… all the way loose and detached at the grip… it revs through the roof. I am at a complete loss, so if anyone far more experienced than me can help, that would be very awesome. I do have a manual, but it is practically useless for this issue. Thanks in advance for any assistance!!!

[Alan H]

For some reason the slides aren't closing when the cables are in. Before fitting the carbs, make sure the slides go all the way to the bottom - they will only need to be up a tiny amount to cause high revs.
Also make sure that the slides are fitted the correct way, i.e. flat base towards the engine, concave (scooped) side towards the air filter.

[mike1161]

Also read through this thread:
viewtopic.php?f=9&t=10488" onclick="window.open(this.href);return false;
The carbs are very sensitive to being over torqued, which can cause the slides to stick in the bodies. I had this same problem, but it's fine now.

[cafe noob]

It was the new cable. I put the old one back on, and all is right as far as that goes. I would like to figure out how to get the new one to work the same way though. LOL. I also had a runaway engine last night, but that was probably from trying to run it with no filter installed??? I hope. She seems to run ok now, just a little idle weirdness, but I can't tell if it's lean or rich. It seems to be doing both. I rode it around the neighborhood for about half an hour just now, and it was pulling great, sounded good, and idled really well at the stop signs, but I fiddled with it more once I got home and now it won't idle. Also when warm, It cranks easier if I open the throttle just a little bit. I'm sure that's a clue, but I'm not sure what to make of that. Stock jetting by the way. I'm running a single small pod filter with the stock intake boot, too. The original air box will no longer fit due to the frame mods for the old cafe conversion. I went with the one filter to maybe get close to the original air flow, as the individual pods would make it super lean. I have a carb kit and some various jets on the way, too, in case that's what I need to sort it out. Hopefully soon, as we are having a very mild winter and it's super fun just roaming around the neighborhood. Thanks for the help.

[cafe noob]

Also, I meant to say, the slides will only go in one way on these carbs. even if you get them mixed up, the guide tab makes you put them in the correct way around. I had thought about that issue first. Thanks.

[cafe noob]

Here's a photo for your help.

[titan performance]

If they are like the 500, you can put the wrong slide in the wrong carb if it's the wrong way around....ie cut out towards the engine.

[Alan H]

Also, I meant to say, the slides will only go in one way on these carbs. even if you get them mixed up, the guide tab makes you put them in the correct way around. I had thought about that issue first. Thanks.

The slides will go in the wrong carbs, backwards, so that the flat part of the slide base is facing the filter and the scooped part of the base is towards the engine. This is the wrong way - trust me I know!!

Nice bike BTW, I always likes the twins, but the 305/315/350 whatever you want to call it wasn't very common in the UK back in the day.

[cafe noob]

If they are like the 500, you can put the wrong slide in the wrong carb if it's the wrong way around....ie cut out towards the engine.

What I was getting at though, was that it appears that both slides are identical. The guide grooves and the cutout in the same place. I thought it was weird, but it works i guess. LOL. I may be leaking air at the carb flange, though. Would that make it hard to sort out the idle? Also, could I make some extra paper gaskets just to make sure I get a good seal? And I thought 2 strokes were supposed to be easier.

[cafe noob]

Also, I meant to say, the slides will only go in one way on these carbs. even if you get them mixed up, the guide tab makes you put them in the correct way around. I had thought about that issue first. Thanks.

The slides will go in the wrong carbs, backwards, so that the flat part of the slide base is facing the filter and the scooped part of the base is towards the engine. This is the wrong way - trust me I know!!

Nice bike BTW, I always likes the twins, but the 305/315/350 whatever you want to call it wasn't very common in the UK back in the day.

Which is funny, as most of the parts I've been getting are coming from the UK. Thank you for the compliment on the bike, as well.

[ConnerVT]

If they are like the 500, you can put the wrong slide in the wrong carb if it's the wrong way around....ie cut out towards the engine.

What I was getting at though, was that it appears that both slides are identical. The guide grooves and the cutout in the same place. I thought it was weird, but it works i guess.

If your 2 slides are identical, that would be a problem.

Your carb bodies aren't identical, are they? The right side carb has the idle speed adjustment and idle jet screws on the right. The left side carb has the throttle and idle screws on the left. Correct? They are mirror image of each other (basically). The slides are the same way.

The slides have a guide groove on one side, and a notch for the throttle idle speed adjustment screw on the other. Set the slides on a table, with the notches facing away from each other. There is a semi-circular cutout on the bottom of the slide. That cutout should face towards the airbox.

[cafe noob]

If they are like the 500, you can put the wrong slide in the wrong carb if it's the wrong way around....ie cut out towards the engine.

What I was getting at though, was that it appears that both slides are identical. The guide grooves and the cutout in the same place. I thought it was weird, but it works i guess.

If your 2 slides are identical, that would be a problem.

Your carb bodies aren't identical, are they? The right side carb has the idle speed adjustment and idle jet screws on the right. The left side carb has the throttle and idle screws on the left. Correct? They are mirror image of each other (basically). The slides are the same way.

The slides have a guide groove on one side, and a notch for the throttle idle speed adjustment screw on the other. Set the slides on a table, with the notches facing away from each other. There is a semi-circular cutout on the bottom of the slide. That cutout should face towards the airbox.

My idle screw is on the top, right next to where the cable goes in. The cutout faces the air filter on both slides. It looks like the only difference in the 2 carbs is the location of the pilot screw and the left one has a vacuum port for the fuel valve. I wonder if it's an earlier carb setup, with it being a '69 model… ?

[elbert]

Could it be that you have a throttle cable for a 250? Been a long time since I played with my 350 but I think the throttle cable end going into the carb is shorter on the 250 since it has 28mm carbs instead of 32mm.

[cafe noob]

Could it be that you have a throttle cable for a 250? Been a long time since I played with my 350 but I think the throttle cable end going into the carb is shorter on the 250 since it has 28mm carbs instead of 32mm.

I suppose that would be very possible. I was considering removing about 1mm of the sheathing on each side to see if that works, as the sheathing on the old cable is very cracked and the cable itself is very sluggish.