How to change main jets

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maleko89

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Remove top cover and side scoops.

Unfasten float bowl vents from air box:
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Lift coolant reservoir and hang off to the right:

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Unplug fuel pump for safety:

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Sorry for this one. Kloker things I'm hot so I figured I would tease him a bit:

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Loosen 3 screws holding left side heat shield on:

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No need to unhook the throttle cables:

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Loosen screw holding fuel feed line to carbs. Slide fuel hose off. Put rag underneath to prevent mess:

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Push hose behind frame cross bar and prop up to prevent any leakage:

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Drain the float bowls into suitable container:

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Now, put the fuel collected back into gas tank. I'm a cheap ass!

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Loosen top screw of carb to manifold boots. One per carb.

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Remove plastic chrome "H" covers. You'll need to re-sync when done:

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Start with one carb and pull up firmly to get out of boot. Work your way around until all four corners are removed:

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Life up on coolant hose and push over right side carbs to prevent the carbs being hung up on it:

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Carefully pull carbs out left side. Be carefully of crankcase breather and vboost servo cable. Feed float bowl breather tubes out the left side under the clutch line. Careful with the throttle cables!

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Turn carbs upside down and hang on left side nub for the top cover. You can see it in the center of the carbs:

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Get 10 mm wrench and remove brass nut to gain access to main jet:

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Check the o-ring on the nut for cracks and wear. Replace if necessary to prevent leaks:

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Ah, there is the main jet! Boo-yah!

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Use the appropriate flat head screw driver. Make sure the blade fits perfectly in the jet slot.

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Loosen the jet 2-3 turns. Use a toothpick to finish it. Make sure it's tight! If it falls you have to break open the float bowl to retrieve it. Do the other 3 carbs just like this. Swap the jets of your choice!

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Here's the vboost adjuster. Might as well check the vboost sync!

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Turn on the key and turn off once vboost cycles open. Use a couple of fingers as shown here to make sure valve is full open. If it's not open all the way, loosen screw in previous picture and move it forward or rearward depending on how it's currently set.

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Carefully turn carbs back over and re-position over the boots. Make sure the drain hoses didn't get caught or pinched anywhere. Again, be careful of the clutch line and vboost servo cable. Here I'm wiggling the drain hoses to make sure they weren't caught or pinched:

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Now, firmly push the carbs down in the boots. Make sure the boots weren't pinched. Here I'm showing that the ridge on the part of the carb that fits in the boot is even with the boot:

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My family telling me to hurry the f*@*@ up!

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On the left side make sure you reconnect the rubber heat shield to the electrical heat shield using the tabs and slots:

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Reconnect the fuel pump connector and turn on/off the key several times to re-fill the float bowls. Make sure you closed the drain screws!

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Re-tighten heat shield bolts and tighten carb boot clamps. With the coolant reservoir off make sure breather fastens to bottom of air box.

ALWAYS RE-SYNC after removing carbs. As you can see, mine are off now:

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Better, but I'm a perfectionist:

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Here we go!

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We're done, it's beer time!

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Nice,

Throw in a couple of photos on how to you removed the air box, and you're in the clear........
 
Damn, new I forgot something. Will add that pic tomorrow. Thanks.
 
Excellent instructions!!!! Heck I even learned something, I usually completely remove the carbs from the bike and change the jets on a bench, like the idea of hanging them off the frame as it saves a step. One thing I usually do is to take a look at the fuel that I drain from each carb. If it has schmutz floating in it I recommend that the fuel filter be changed and that the fuel system get a good cleaning. Nothing worse than making a change and having the bike take a dump due to debris in the fuel.
 
Nothing like a 10.00 see through fuel filter from your local autoparts store.
Sure does save a lot of carb headaches. And the fit perfect right before the carb fuel inlet
 
Amen!! I have a Mr. Gasket clear fuel filter that can be cleaned. Check it quite regularly to see if there is any debris on it, especially after winter storage. Clean 2x per season and haven't had a problem yet, knock on wood.:eusa_dance: Oh yeah, and Mark, no one is allowed to look that happy LOL.
 
LoL, that's because you can't see the beer sitting on my tool chest behind me! Mmmm, Blue Moon.
 
Very nice post Mark. Wonder where you got that spiffy airbox setup - LOL!

Just for those interested in a short cut. Most of the time you can actually leave the throttle cables hooked to the junction block. Slide it out and turn them over (I also let them drain through the vents all four at one time into a container at this step). Set the rack right onto the upper frame rails and you can go to work. Don't forget to put a rag over the open manifolds just in case you drop something it doesn't go down into the engine. The brass parts will not come back out with a magnet if you make a three pointer with them.

Make sure that the jet fits snugly on the toothpick. Get new picks as needed to make sure they are on there tightly.

Sean Morley
 
Thanks man!

I didn't disconnect the throttle cables. I learned that trick along with turning upside down on frame for you in Topeka 2006.
 
I really could have done without the hairy leg shot...:barf:

Seth had that same look on his face when I was there the other day... cute kid... your mailman must be adorable...haha

Great write up!! Although I think I need to see you do it in person just to make sure I got it right... How about Sun? I need to try and get back to the 132.45Hp settings before Topeka and then give Morley's magic kit a run at it.


Frank
 
Hey Mark
If your not busy tonight could you do the same with the step by step instructions along with plenty of pics on how to remove the engine to check main bearing clearances and installing the engine if you have time also show us some tuning tricks.:rofl_200:

Great intructions on the main jet 101 course..
 
I'm afraid not, I've never had my engine apart before so not much help. I'm sure it's just like putting a puzzle together right? lol
 
Excellent job Mark!!

This kind of DIY instuctional post, and guys like you, are why I love this place so much... If it weren't for VMF, I'd not be able to afford to keep my bike in good running condition at all. Good pics..thanks much for taking the time to do this, and share with all like me who are trying very hard to learn, and catch up...

Great lookin' family too! You're a very Blessed guy!

Yer Uncle Philthy Loves Ya!!
 
wish I would have seen this post before messing with the throttle linkage

I am about to tear into the bike again (probably season ending stuff) tonight to track down my fuel delivery gremlin

Mark fantastic post and I second what Crouching Uncle-Philthy Hidden Camera said.....without someone taking the time to post up instructional pictures like this my local yam dealer would be installing a heli pad at the cottage

Very much appreciated by all
 
I'm sorry, but I don't understand what the toothpick is for...? Do you stick that into the main jet top hole to be able to pull it out?
 
Correct. Jam it in the main jet and carefully lift it out.
 
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