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Re:ARGH! Still acting lean, but... Was Re:float level
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TOPIC: Re:ARGH! Still acting lean, but... Was Re:float level
#1010814
Jaybo (User)
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float level 9 Months, 2 Weeks ago  
I read the the tech article and I am a tad confused, Measuring in the front I am at 11mm float height, so would that be right at the height of the back mating surface? that seems to be right there in the level in the article. Reading through some of the threads on a search, they talk about 4mm above the rear surface. Which is it?

Carb was apart for the BAK. Grizzly valve, 170/37.5 jetting, with the BAK needle & pumpless. Curts ported manifold with new Orings, new to me 3" HK's with brand new gaskets. Carb was working fine before. Now it sputters and spits and will die once the enrichener is off after warmed up.

Oh and bike is level, on the stand.
 
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Last Edit: 2017/05/14 19:06 By Jaybo.
 
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#1010827
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Re:float level 9 Months, 2 Weeks ago  
Level with the mating surface is based on outdated specs. Yamaha released technical update bulletin some years back, stating the fuel level should be about 4-5mm *above* than the mating surface. I wrote a pretty detailed thread on it 2 years ago: http://roadstarclinic.com/component/option,com_fireboard/Itemid,187/func,view/catid,12/id,882456/
 
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Last Edit: 2017/05/14 23:40 By Doc_V.
 


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#1010831
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Re:float level 9 Months, 2 Weeks ago  
Sounds like you have an air leak
 
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#1010832
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Re:float level 9 Months, 2 Weeks ago  
You want to be measuring on the manifold side(backside) of the carb. Backside is another way of saying it, only you have to think about backside as the carb sets, not the bike. The front of the carb being the side the air enters, and the backside, being the side the air leaves on its way to the cylinders.

4mm is the correct level. Measured along the backside of the carb. You should be fine anywhere from 3 to 5mm. Yamaha revised the original level around 2000 something or other, so all use the 04 and later spec now.

Along the lines of what davej said. You either have a air leak, or, while working on the carb, some small piece of something has blocked the Pilot jet so you're not getting any fuel on the low end, without the enricher. If your confident about no air leaks, I'd remove the Pilot, and inspect it. While it was out, I'd blast some carb cleaner into the Pilot passage, after removing the PMS and it's spring, washer and oring.
 
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#1010833
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Re:float level 9 Months, 2 Weeks ago  
Why don't someone set their carb float level using the backside then convert it to a front side measurement so you guys can quit playing games trying to get a backside measurement?
 
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#1010834
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Re:float level 9 Months, 2 Weeks ago  
davej wrote:
Why don't someone set their carb float level using the backside then convert it to a front side measurement so you guys can quit playing games trying to get a backside measurement?

I think 10 or 11 above the front seam, Is equal to even with the seam at the rear, and, "If" all things are equal, the front should measure about 14. I'm not really sure why Yamaha uses the back edge. If the carb hangs(droops)a bit, the front may add a little more error????
 
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#1011198
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ARGH! Still acting lean, but... Was Re:float level 9 Months, 1 Week ago  
OK, so I just pulled my carb off again, to blow it out, again, and all mentions of the starter jet (behind the main) is to just leave it alone. OK fine, I did take it out and blow carb cleaner through the passage but I figured the hole in the starter jet was just really damned tiny. Taking a closer look, it's plugged completely. Is that normal? How big should that hole be if it isn't? It isn't like some kind of crud, it looks like the same brass color just like a jet with no hole. There are no markings on the jet at all.

SKWEARpeg wrote:
You want to be measuring on the manifold side(backside) of the carb. Backside is another way of saying it, only you have to think about backside as the carb sets, not the bike. The front of the carb being the side the air enters, and the backside, being the side the air leaves on its way to the cylinders.

4mm is the correct level. Measured along the backside of the carb. You should be fine anywhere from 3 to 5mm. Yamaha revised the original level around 2000 something or other, so all use the 04 and later spec now.

Along the lines of what davej said. You either have a air leak, or, while working on the carb, some small piece of something has blocked the Pilot jet so you're not getting any fuel on the low end, without the enricher. If your confident about no air leaks, I'd remove the Pilot, and inspect it. While it was out, I'd blast some carb cleaner into the Pilot passage, after removing the PMS and it's spring, washer and oring.
 
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#1011199
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Re:ARGH! Still acting lean, but... Was Re:float level 9 Months, 1 Week ago  
Its normal. Just don't stick it in the hole the main is supposed to be in.
 
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#1011200
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Re:ARGH! Still acting lean, but... Was Re:float level 9 Months, 1 Week ago  
OK, well I'll put it back on, I pulled my manifold and double checked it, polished the surface on the jugs inspected the new orings gave them a light coat of grease and no air leaks.I just sprayed carb cleaner through everything yet again so will see if it made any difference. I did raise my needle all the way as well but that had no impact. I'll go put it back together again after I eat and see if any change, again. Ugh. I want an EFI Roadie!
 
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#1011202
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Re:ARGH! Still acting lean, but... Was Re:float level 9 Months, 1 Week ago  
 
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Last Edit: 2017/05/19 20:51 By Shores.
 

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