i am just going to borrow a friends gauge kind for now and then order a set for myself. now i just need to go out and get a manual for my bike before i start all this.

 

When you check compression you have to hold the throttle WFO...

When you clean your carbs there is more to it than just wiping residue out of the float bowls, you need to remove the jets and soak them in carb cleaner then use compressed air to blow them out.

Remove the choke pins and clean them

Then you need to spray carb cleaner into every little pinhole passageway in the carb and blow those out with compressed air.

Check the vacuum diaphragms for holes.

Check the float needles and seats for damage and wear, also check that the plastic floats do not have fuel inside of them (leaking).

Check / set the float levels.

Installing a jet kit is easier than everything I've just explained, you simply remove the main jets in all carbs and replace with the recommended jets that come with the kit. Then you remove the stock springs and needles and replace with new springs and needles with the clips in the recommended position. You may need to epoxy one of the holes on the bottom of the vacuum slides if recommended in the kit.

Your idea of how exhaust and air filter modifications affect your jetting is backwards though.

When you install a free flowing exhaust and air filter you are making the conditions LEAN not RICH.

This means you are allowing more AIR into the motor, not fuel.

That is why a jet kit will allow more fuel into the mixture with bigger jets and an adjustable needle, the backfiring and popping sounds you hear are mainly on deceleration, correct?

That is indicative of a LEAN mixture (less fuel, more air)... Running your motor LEAN for too long will eventually cause damage in your valves, valve seats and piston rings - LEAN conditions cause your motor to run very HOT!

Good luck! If this is all over your head... You had better start reading and learning and maybe enlist a friend who knows what he is doing to give you a hand [8D]


P.S. - Spark plugs never lie... to check your fuel mixture after making carburetor adjustments, go for a test ride and bring the engine to operating temperature and ride the bike like you would normally... When you get back home shut the motor off immediately (don't allow it to idle for 5 minutes).

Then pull your plugs and check the coloration:

Dark black and "fluffy" carbon deposits means you're too rich (too much fuel).
White blistered looking plugs are lean (not enough fuel)
Grey to lightish-brown is a good running cylinder.

If you find oil on your plugs it's time for either new piston rings, new valve guides, or valve stem seals. (or all 3)

 

wow, thanks for all the explonations. I have the know how to do it all I was just backwards on the lean and rich definitions. Thanks for clearing that up. I will check the compression again with the throttle open and see what numbers I get. Yes the backfiring is mostly when I let off the gas. As for plug color, 2 of the plugs are whitish yellow and 2 are wet when I pull them. I'm going to install my jet kit this week. After that I'll sync the carbs and see where I'm at. In order to clean everything better I'm going to have to get a new air compressor. Mine died and I have been putting off getting a new one for so long. Right now I have the carbs off and laying on the bench. I'm going to tear them down after I go buy the manual for my bike tomorrow. Thanks again for everything you explained out

 

You probably don't have to buy the manual for your bike, there are many free PDF versions online.

I'm rebuilding an F3 carb right now, and it was strange to me that the 2 outer carbs have larger main jets than the 2 inner carbs.

The outers have 140 mains and the inners have 138's.

Maybe somebody here that knows the F3 better can explain this, I ride an F2.

 

Hmm... Normally the two inner carbs have the larger jets...

 

I might have described it backwards, I can't remember haha... I just know that they are different.

 

yeah i just found a link for it on the forum here. i love this place. i need to see what they jet kit manual says about the different size jets. does anyone know more about what size jets are needed for a stage one jet kit?

 

my biggest concern is the shop here in town wants $700 to jet the carbs and sync them. thats just crazy

 

yeah that is crazy, change the jets yourself and find an honest shop... $50 for a carb sync is more like it.

The dynojet jet kit specific to your bike will have all of the directions you need, and technical support on their website.

 

This is Vegas, there aren't any honest shops... Wish you had a way to get that thing over here, I'd give you a hand.