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Hopefully I can get this posted. Very poor signal here.
There are 2 different carb mods for the 1200. The first and primary one is the fuel pressure balance mod. This requires drilling out the return orifice to 1/8" and installing a jet in the return line. This will balance the pressure between carbs and if one pump dies the other 2 will supply fuel for it. I beleave I sent this earlier but can resend at the moment as I can't get a good enough signal. How erver you can find it on greenhulk.com under the Yamaha how to's section about half way down page. The other is a change in Jets and needle seats for if you go to flame aresters rather than the stock air box. And it's first on the list under how to's.
 

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Discussion Starter #142
Bought these two
https://www.ebay.com/itm/Yamaha-XL1200-XLT1200-99-05-Genuine-Mikuni-Triple-Carb-Rebuild-Kit-Needle-Seat/192470876588?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
https://www.ebay.com/itm/Mikuni-Pop-Off-Pump-Gauge-100psi/332589884361?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
Got a great deal at $250 minus 15% per eBay discount. The carb kit comes with 1.2 stock needle and seats so I will eave that alone but want to do the other mod with the return line but got to read a bit about it.
 

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Read the instructions for the kits. The check valve have to be installed correctly as they concaved, and be careful with the little rubber plugs that hold them in. They break easily. I made a tool out of a old torx driver. Just don't use anything that has squared off edges or pointed. Lubing the new one with some oil will help, and also working it from the back side of the pump to finish helps.
Blue line faces up away from the body. Install the plug in the check valve, then install into the body.
Do one carb at a time so you don't get the mixture screws mixed up per carb.
 

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For the little rubber plug that holds the pump valve in place I use a ball end Allen wrench that fits the back side hole. Use 2stroke oil to lube hole and rubber plug
 

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Discussion Starter #148
As soon as I get the kits I will post here to get a better understanding of what to watch out for. I will also study the manual which I am sure mentions some stuff. Thanks for the tips
 

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Discussion Starter #149
Hi guys blast from the past here. Sorry I have neglected this thread have been involved with a few time consuming projects and a personal uncle health issue and I just put everything on hold forever.
But 2 weeks ago I actually completed the rebuild on the XL1200LTD and then I came back to this thread and reread it all a few times as it is really descriptive and helpful. That's how I actually realized that I already had the carburetors rebuild kits. I did the rebuild on them last night and now I went over Dave's post that mentioned the modes available for this it Greenhalk.com
I went over there and read the whole post on taping the return line on the last (P) #1 carb using the M5x0.8 tap and drilling the return orifice out, using an 1/8" drill bit all this to install the Mikuni main jet 95. I am trying to locate one and going to EBay I found some.

or

And wanted to know if I need to put anything on the tap to keep it from leaking.
I haven't checked the carbs with the popoff pump yet and I know that is important.
Thanks guys and sorry again for the long delay in response.
 

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Welcome back, hope all is well.

Nothing needed after tapping the threads into the last T. just install the jet and install the hose overtop of it all like normal.
You want the first jet shown in pic 1.
 

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Discussion Starter #151
Welcome back, hope all is well.

Nothing needed after tapping the threads into the last T. just install the jet and install the hose overtop of it all like normal.
You want the first jet shown in pic 1.
So I used the 1/8 drill and made holes as per instructions and used the M5, .8mm tap. So you think the 6mm jet is the one?
 

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Discussion Starter #152
So I used the 1/8 drill and made holes as per instructions and used the M5, .8mm tap. So you think the 6mm jet is the one?
Also I had to open the carb pump side up to drill it and wanted to see if it's safe to reuse after initially tightening it up. They should be ok. On the 4 bolts shouldn't I put some loctite they were pretty loose when opened for the rebuild.
I also have a question on the hi and low speed adjustments. Have the paper from greenhulk but is the factory lean? And should they all be the same or each its own setup.
 

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Yes the first jet pic of the 6mm one is the one you want to use.

If gaskets didn't get damaged they should be fine.
I don't use locktite, but you can just be very sparing with it. Some day you may have to take it apart again.

Set each high/low screw back to where each one was Pryor to disassembly. Each carb has subtle differences. If you didn't record screw settings use what's listed with directions.
 

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Discussion Starter #154
They were all 1.5 or 1.75. Here is the paper I got. I assume that the xl1200ltd is the 1200cc right? Confused on the high speed screw settings it has -1/2(M,P), 7/8 (C) +/- 1/4 how would you interpret that.
15904392113517184288150449511345.jpg
 

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"Confused on the high speed screw settings it has -1/2(M,P), 7/8 (C) +/- 1/4 how would you interpret that"

That states the first and Third carb are 1/2 turn out. And center carb is 7/8 turn. That's for rough starting location. Then the +/-1/4 means, you may be a 1/4 turn in or out from those setting when properly tuned.

You want the pump on your fuel in connection. Only need to block return Fitting. Put WD40 on needle and it should pop around 70/80 psi. Watch out when it pops WD40 mist will go everywhere.
 

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Discussion Starter #159
Yes fuel in is the pump and it's a dual connector and the out or return is blocked and I have to block the other side of it also. So 80psi is ok for this one? Which means I should use the 1200R for low high speed from the sbt chart?
 
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