As to parts numbering, it has been my experience that the first set of numbers are very significant. The remainder of the part number denote a series of a part, and explains the same numbering of the XT and TT front axle. I do believe they are different though, since you have both, are the front axle's exactly the same or is there some difference, like a way to pull the TT axle out?

In other words, if the first numbers are different, the part is unique. You have to go by the entire part number.

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'84 XT600 is now bored to 2nd oversize and new OEM pistons and rings installed. No more smoking.

Ive done a bunch of parts comparing with the parts physically in my hands to double check and other checking into it. The first three numbers are mostly just the model that part is for or made for,( like 34l= '84xt600/motorcycle, 5lp=raptor atv,ect...) I've found that series has little to do with the actual part. It's the second series that is the specific part and design, the third 3 is any re-designs or updates ( this is where there can be some changes to the part), the fourth I'm not sure. I've probably confirmed this with about 20 parts that the first number are totally different but the 2nd series is indentical and the parts are the same .

Now this isn't fail proof or exact, but you would be surprised once you start to physically have the 2 parts in hand and make note of the numbers , how many parts are used across the model line, just the first number changes.

For instance, the oil pump on the '90 XT600 vs 2005 Raptor 660 atv
................................... 3AJ-13300-00-00 vs 5LP-13300-00-00
both of these parts are identical, I have both and measured them to confirm.


Many of these parts, like those jets, on Boats.net when you select the part number it shows a list of what models that part fits, and quite often it comes up with bikes , atv, scooter, snowmobiles , all across Yamaha's lineup ,using that part or could use it.

I'm really finding this out as I am putting the XT600 cylinder and top end on top of a 660 Raptor bottom, everything bolted right up, cam chain fits the 600 cam gear(same part #), the 600 piston fits the 660 con-rod( same stroke), many parts are the same # except the first series. Of course I haven't fired it up yet

I didn't know you mentioned the wire trick. At the UK site was the first I had heard of it. It seems like an okay temporary trick. It seems that it would be good to use if one was curious if a leaner jet would be worth purchasing, in a pinch on a tour up into the mountains & things get too rich or on a bike that doesn't get ridden much, ect.

Another part I ordered for my XT carbs is the newer pilot set screw from the 1990 & newer XT600. I am curious as how it will compare to the older screw.

I can't wait to see this project XT Top/Raptor bottom. Have you got a thread up yet with some pics of the project?

Good luck getting the Raptor carbs going too. I may do the Ninja or Raptor carb conversion after I play with the TK YDISs some more. After doing research on all these TT & XTs I am also wondering if the carbs off the newest XT660 or TT600 sold in Europe will work on the old motors. Another avenue I want to look into is some kind of throttle body fuel injection. A fuel injection conversion would probably be spendy but sure would be sweet.

THE newer 660 bikes are single carbs, which you can get a Grizzly 600 intake that reduces the two carb designed head into a single carb, but then you run into room with the shock. A person would need to have an offset intake so the carb sits a little crooked then the airbox boot could get to it.
I recently bid on but lost, a Raptor 700 EFI throttle body and harness, that would be a good one, especially with the 660 bottom, it has a few more sensor the efi uses. A person can sometimes get the whole system for $350-$400, maybe next year once I have all my projects settled in and get bored again

That secondary jet adaptor would be a good idea, but if these 350 or 225 jets do indeed fit it will provide many of the options one would need then. I wonder if the adjustable needles or the entire secondary slide would fit from there, if it has an adjustable needle.

I also bought a set of four Mikuni's from a Kawi street bike that are 32mm (IIRC), I got them for $45, will need to fab some throttle connections and mounts though. The Raptor carbs fit right on except the snout is another 4mm bigger dia. so the boots need to be ground bigger id or the carbs need to be machined smaller od. That's one of my biggest holdups, I've been trying to find another model/brand that has boots to fit the carbs and can be easily modded or bolt right up to the head. I hate to cut up $80 boots.

Ah bummer on the new XT660 carbs. I know of the troubles installing a single carb. I didn't realize the XT660s had a single carb.

Well the 350 has the other style of secondary jet like the 1990 & up XT600e carbs. So only the primary main jets can swap over to the older XT600s but not the secondary main jets. Maybe there is some other stuff that fits too. I am not sure.

The Raptor EFI sounds sweet. I saw it was a single throttle body though. To bad it can't be a dual body setup.

If the Ninja 250 carbs fit how about a Ninja 250 EFI conversion? Here is one Kawasaki Ninja 250r Fuel Injection Conversion Kit - Small Engine EFI Conversion kit | fuel injection kits I am not sure if this is the right kit that matches the carbs that fit the XT. What year of Ninja 250 carbs work for the XT carb conversion?

If I'd get the 700r EFI system I was planning on making my own intake to go to the single and have either the throttle body offset or move the shock over an inch or so to make room.

That Ninja EFI system I haven't seen before and looks rather interesting. I don't know how it would work because of the cc difference and whether the nozzles can be pulsed enough to throw enough fuel or if bigger nozzle can be gotten for it. Might be worth investigating further though. I've always had that itch for fueling these old bikes or at least one for a daily driver.

That is a good point about the the cc difference. This is definitely something to look into. Maybe a custom kit could be put together. The same company makes a 400-800cc single body kit. I bet if the situation was looked into something could be built.

A fuel injected 43f XT600 would be sweeeeeet! The best part of EFI is as the Ninja kit description says " • Fully tunable with laptop tuning software (free). No need to add any other piggyback device Programmed right with a good kit it would be hard to keep the front wheel on the ground I bet if the throttle has utilized in a heavy manner. The EFI could also be programmed for fuel economy too. Once the programs were created all it would take would be a few minutes of horsing around with a PC to swap programs.

Not true , ALL XT / TT 350, ALL XT/TT 550 , 600, 660 up to 2003 all have TK double carbs , and are all very alike.

The "new" 660 engien in the XTR and XTX 660 from 2004-today and also used in the XTZ from 2008-today are single trothle body injection

As for jets and carbs the 2kf model XT 600 has a slitgly different, bigger tk 27 , the same that is used in the 660 tenere from 92-99 and the TT600 , also
the later TT 600 R also has a different one with a diferent jets

you could try ato get a more recent carb from a european model and maybe be easier to get jets for that

also some models in europe were power limited to local licence limitaitons , theses had different jetting also , if you can hget these you could just drill them out

also check the swiss spec bikes that had different carb setiting (generally leaner)

The Y26PV found on approximately 1991 & newer XT600s uses the same style primary carburetor main jets & pilot jets as the older Y27PV carbs found on approximately 1989 & older XT600s. The jet orifice sizes may change from year to year or model to model or country to country but the actual jet style does not change for the primary main or pilot jets. The secondary main jets are not the same style between the two carbs though. The 1989 & older Y27PV secondary jets are no longer available. The newer Y26PV secondary main jets are still available thru Yamaha & a company called Kedo out of Germany. The selection of these Y26PV secondary main jets sold new is limited & some are very expensive. Because the selection is so limited & costly swapping to these newer TK YDIS carbs is not really that much of an advantage. The chart of jets I put together on page one of this thread shows the Y26PV secondary main jets Yamaha sells #100, #106 & #125. Kedo sells #110 #120 #125 very high prices. If another source for these secondary jets for the Y26PV could be found or if a person hunted up obsolete Yamaha secondary jets then maybe it may make more sense.

Just to be sure everyone reading this is on the same page I would also like to note that the Teikei model numbers of these carbs is confusing if you are unaware of these carb's specifications. The 1989 & older Y27PV is a 27mm carburetor & the 1991-2003 Y26PV carburetor is a 28mm carburetor. Why the second generation of the carb wasn't call a Y28PV I do not know. At any rate a Y27PV is a 27mm carb & a Y26PV is a 28mm carb.

One other thing I would like to note is that in America since the 1990-1995 XT600e was still sold & had a Y26PV carburetor it is not necessary to buy such a carb from Europe per say as they are often available in America used. Ebay has them for sale sometimes as do motorcycle salvage yards. Europe over all probably has more for sale at any given time though the shipping can be cost prohibitive for them to be bought by someone in the US.

Here is a link to a chart showing specifications on XT600s from 1984 - 2003 including when the change in carb models occurred. Wartungsdaten XT600-Modelle

Here is a link to 1984 XT600 specs showing a 27mm carb Yamaha XT600

Here is a link to 1989 XT600 specs showing a 27mm carb Yamaha XT 600

Here is a link to 1990 XT600e specs showing a 28mm carb Y26PV Motorcycle Specs

Here is a link to 2003 XT600e specs showing a 28mm carb Y26PV Yamaha XT 600E

Here is a link to Kedo's page KEDO - Performance Products