2003 Xt600e carb sync help
 

After lots of looking I couldn't find a good post about syncing the carbs on my 2003. It was sitting for awhile when I was in the USA so now it has been popping back through the carb. Also the quality of gas here in the Dominican Republic isn't the greatest so I feel a good scrub would do wonders. Which brings me to the next thing. My first time ever syncing carbs. Here in the DR there isn't a good Yamaha shop near by and I also do all of my own wrenching. I want to make sure I know step by step how to sync before I start rooting around in something I wasn't prepared for, living in a land where XT parts are more of a unicorn.. (Been wrenching for over 11 years and my first carb sync scares me. Haha) Any links, tips, tricks, hacks or Grey hairs of wisdom are welcome. Even a point to the tread I missed where this was already discusted.:oops2:

Theres not much to sync.

The slide on the primary carb should open 6mm before the secondary carbs open. Insert a 6mm drill into the primary carb, and adjust the screw between the 2 carbs to meet spec.

carbs should reach full open at the same time or one will prevent the other from opening all the way. I adjust them to reach full throttle at the same time, and the secondary carb delay is what it is. THUMPTHUMP

The secondary is vacuum operated , can't be set at wide open because it doesn't move with the other one. It gets set by when it can start to open (when vacuum can move it. It's done as Jens said.

Yep, that’s how i did mine. :smartass:

Mezo.

jj talking about the linkage for the butterfly dude. That is what you sink. The cable pulls the linkage for the primary carb, then after a 1/4 throttle or so the adjustable screw picks up the cam/ linkage for the butterfly in the carb to open allowing air to be pulled through the secondary carb that creates the vacume to lift the slide . The cam/ linkage on the primary and secondary carbs have different ratios so that the secondary can open the butterfly later but still open to max the same time the primary reaches full throttle .THUMPTHUMP

Sticky on opening page of this forum contains a link to download genuine Yamaha manual for your bike.

It is brilliant in detail. Carb section 5 page 13, says 7mm. Thump*3 method interesting.

But your problem is more likely due to old fuel. A fuel stabilizer can help prevent gum and varnish deposits caused by stale fuel.

Happens in the classic car / bike world and very good for business.

p

analyze a carb off the bike and move the linkage that the cable pulls and watch the butterflys on both carbs. You will see what I mean. If you do not adjust it based on the butterflys you will not get full open butterflys on both carbs at wide open throttle .I am not saying that 7mm will not achieve this just that if it does not you will not get maximum air flow. THUMPTHUMP

@ Thump*3: You are quite correct. My post was rather at the original poster, a newby.
It is my policy to wait and see if the person will reveal more about himself and, if another forum member would have pertinent advice. He didn't and i found no pertinent advice. But he did mention 'a good scrubbing', so is maybe rolling eyes at where his thread has gone:D

It is my experience that sync in a carburettor does not go out from 'standing'. And the best post he could find, the manual, is right here.

I meant no disrespect to your post, quite the contrary. In my opinion it shows lateral thinking, an ability to understand how thing work, fairly rare.

with regards bier
p

Hang on? JJ you posted in the wrong thread. doh

Mezo.

Yep deleted !

As for the syncing, the secondary carb butterfly is fully open quite a while before the throttle gets all the way to full lock. There is a flattening plane if you look at how it's made on the linkage where the roller runs that there is quite a bit of overlap as to when it is open and when the linkage stops, thus why they say have it speced at closed

Do not sweat it pete j . No one getting offended here. There is almost always more than one approach to everything. There are several of us that can not leave well enough alone. So, we try things , some work some do not. But, that is why we ask for advice , opinions , and experiences form others. The different methods posted here will probably result in similar results. I changed the secondary carb engagement all over the place when trying to overcome the challenges of running air pods on a conventional carb and a cv carb. I found the jetting and settings that worked for me. I wanted to be sure that both butterflys will be at full open at the same time. jj is correct in what he has said, the secondary will actually go past parallel and begin to close off again, just a little. But I was not aware that the secondary can actually be wide open and wait for the mechanical primary to get there, if I picture it right in my head. I will measure both bikes to see where the measurement for the delay gap ended. I use the early carbs on the 86 as well as the 90 Estart. I put some ninja carbs on but do not think I can fix the mid range without an air box. THUMPTHUMP

Thanks guys for all the help. Yes I have had the pdf of my bikes manual, but sometimes on things, what that manual says and what a guy who has done it 45 times before says can differ. God knows it never seams to work out like how the manual puts it. I have tried a sortment of fuel this and thats but nothing. Just wanted to understand the tips, hacks, and tricks of the more experienced ones here. Something came up and the xt got put on the back burner but today is my "fix my bikes" day. :scooter: Ya I'm not the one to roll my eyes haha. I want to know everything. When I was still in the states I talked to a bike guru, the Yoda of everything Yamaha, for a good hour and a half about a few things on my Dominican Monster. Thanks @thumpthumpthump great advice! Also great point Jen E.