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Got this new bike from a friend and he said he thinks he put to big of a jet in it so it won't start, before he worked on the carb the bike ran great and really strong I rode it myself, I hope someone can tell me what I can do and just basic knowledge on four stroke carbs as I am new to it. Thanks 

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There is no such thing as a 'basic' introduction to that carb.

Every part of the carb is interdependent on another, to some extent.

Put in stock jet sizes, replace the worn emulstion tube and slide plate seal, and that is enough for now.  You do not change jetting to compensate for other issues on the bike, the most common being worn out valves/seats.

The vent hoses need to be routed up and filtered (thats where all the dirt is coming from) and the fuel line needs an in line high-flow filter (like a golan)

There are mods to the accelerator pump you can find by searching.

 

http://www.pbase.com/jdjetting1/keihin_fcr_manual_views&page=all

http://www.dirtrider.com/features/protips/141_0707_keihin_fcr_carb_rebuild/

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Thanks, I managed to get the bike running yesterday and it would idle but somewhat rough and wouldn't rev up good. I already ordered a kit for the carb. But what are the two like chokes on the carb one is red and the other black? 

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1 hour ago, Gravett1 said:

Thanks, I managed to get the bike running yesterday and it would idle but somewhat rough and wouldn't rev up good. I already ordered a kit for the carb. But what are the two like chokes on the carb one is red and the other black? 

Choke and hot start. Read the links. 

By the way, the rebuild kit you ordered will not have the parts you need.....you need to order them from Yamaha. 

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Ok thanks and I think the kit should have everything atleast it looks that way from the pic

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Also what is this for? I unscrewed it and it's a dip stick I just don't know what for. 

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18 minutes ago, Gravett1 said:

Also what is this for? I unscrewed it and it's a dip stick I just don't know what for. 

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Dude, you should not even start that bike till you download a free service manual from Yamaha's website, and READ it.

That is the oil in frame check point.

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1 hour ago, Gravett1 said:

Wow I just sounded like such a ass, sorry🤦‍♂️

I was a bit snippy my self, but man o man, not knowing where the oil goes is a huge red flag......

 

By the way, that rebuild kit does not use OEM jets, so you may have issues. You should only use Keihin or JD jets in a Keihin carb.

The kits also leave out other important parts that need replacing:

  • Acceleratorp pump diaphragm
  • Emulsion tube / Needle jet (they wear every year or two)

Make sure the accelerator pump works BEFORE you put the carb back in the bike.

 

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Ok thanks a lot! I needed a kit anyway for the gaskets but if I need to order jets then so be it.

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