We've had a couple hours without rain in Seattle the past week, so I cleaned and tuned my YDLS carbs on my 1986 Yamaha XT600. I had a really hard time getting both the airbox and manifold mouths of the carb to fit into the boots on both sides. It seems like the spacing between the boots and hoses is a few mm too wide for the carb.

I ended up removing all of the bolts on the air box and moving it forward toward the engine enough to barely get the hoses and boots over the ports on the carbs.

Unfortunately, a couple of the screws on the old clamps are stripped and I can't get the clamps to tighten. I'd like to replace the screws or maybe the clamps.

I have two questions:

Does anyone have tips for getting the YDLS carbs to fit snug inside the manifold boots and hoses from the airbox?

Does anyone know what size/thread screws could replace the OEM hose clamp screws?

Thank you much and hope everyone is staying safe and healthy!

could answer partially -
1. spacing situation on my bike seems to be just opposite: carbs fit very tight. also, due to some modifications, i've got even restricted access, so easiest method for me is bit longer both for the removal or installation: all bolts from airbox (including lower one, next to upper chain guide) should be removed. this gives some space to manipulate.
then i remove bolt of rear brake fluid container as well as ignition coil and intake manifold on the right side. only then i'm able to remove/install carbs from the right side.
tubes from airbox have curved shape, they could compress or stretch, i always connect them prior to intake manifolds. you might use screwdriver or something similar as a leverage to push airbox towards the engine during assembly.
2. on intake manifolds i have different, stronger clamps and don't remember their predecessors. on the airbox clamps, there're 4x0.7 bolts (supposedly jis), same as on the oem clamps on the boots of the front fork, maybe different length.

Thanks. It's always something, right? Well, I did some measuring and it looks like the OD of my intake manifold boots is 1.9". I ordered a couple clamps off of ebay in that range with .25" wide bands.

Having the flat head bolt will hopefully make it easier to tighten them down, once I finally have them where they need to be... haha.

Other than that, the bike is running well. 3 1/4 turn out AF mix. Upjetted main and stock pilot. Got my float height bench set to 27mm. Carbs are clean with new gaskets and float needle. Aftermarket exhaust the PO put a hole in and patched up... I got the bike for free basically, so I'm cool with that.

Hopefully get these vacuum leaks sealed up and start riding.

In a pinch, when those clamps stripped, I have used commonly available hose clamps, although they don't fit quite the same - a hose clamp is wider and doesn't fit the groove in the rubber boot quite right. You have to be careful if the clamp is holding the boot to a plastic air tube, turning a hose-clamp screw with a nut driver generates way more clamping force than a stock boot clamp.

Sometimes to get the rubber boots where they need to go, you can use petroleum jelly to get them to move/slide easier, but that also makes it easier for the boots to move/slide off where they belong, and compromise air-filtering. A hair dryer can heat them up a bit and make the boots a lot more pliable.

My new-to-me 1985 XT600 needs carb removed and cleaned and put back in... its been sitting a couple years with regular-ethanol-blend gas in it. Didn't even try to start it.

Do we call this carburetor setup "carburetors" or is it a single carburetor? No matter, it/they still has to come out, apart, and get clean.

Did you obtain a "kit" for this carb? Where did you find it... My local Yamaha dealer says that I should take it apart and order (with a few weeks wait) each individual bit-part I might think I need...

Loosening out the air-filter box is a great tip, thanks.

Does anyone have a service manual for this 84-89 series, the only one I find online is the 90-newer with electric-start.

Thanks...