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That is pretty close. The physics of a regular carb for a car and a float diaphragm carb (FDC) are basically the same. When a FDC carburetor has too much pop-off, it will start, but it will not transition from low to high speed circuit. Modern FDC carbs use a pilot circuit, not a low speed...

I really don't like making absolute statements. it is entirely possible that 2 mechanics can have different skill sets and work experience that apply to the same subject. But this nonsense about pop-off has been going on for more than 30 years. First: Pop-off is a better tool for rebuilding...

2 turns on the low (pilot) screw, and a low pop-off will kill top end. Why do you Fricken think you need a different pop-off than the jet specs for the pipe?? There is many things more important than pop-off. Pop-Off isn't as important as some web sites claim. Pop-off is inter-dependant on the...

Because it took a long time to restart, I do not believe the engine seized. I also don't believe it cold seized. That said, when you ride and it is cold, normally you need to rejet the carbs for more fuel. Engines need richer jetting in cold air. Maybe cold water too? I don't know what your...

The best single pipe for a 900/1100 Kawi is a copy of a Rotax 1/2 pipe used on ultralights. But no one makes one. The stock 900 and 1100 pipes look like a regular pipe, but it doesn't function as a normal pipe because it only scavenges. Any return wave is wasted. On the dyno, a dried out stock...

After taking a second look at this paragraph, I wish that I explained it better. So I edited it. It needed to "start with good specs" Many good specs for sbn carbs use 80 gr springs. In fact a spec that includes an 80gr springs generally work out very well. Rewritten: A method for developing...

Which 1100? and how is it set-up? Is it the SXI with the 1100 engine? What carburetor brand? and we need to talk about pipes. Bill M.

You might see "No Rev Limiter" as a feature, but when DB @ ProTec first started modifying Yamaha rev limiters, he removed the rev limiter. DB (ProTec) was also racing at the time and the cdi's with no rev limiters were snapping off the nose of the crank. Then he started using a mod to make the...

Has it ever happened before? Because it was hard to re-start I would look at the fuel system. If it had seized for the first time, most engines will usually restart quickly. That is one reason why seized engines are seized repeatedly 5 or 10 times. Have you ever replaced the fuel tank filler...

First off, carbs are not designed to respond to snapping the throttle open. It causes a lean spot. But your complaint is one function of the main jet check valve. Preventing a bog after you get off the throttle and then accelerate, and assisting the starting is its 2 main functions. When you...

A method for developing your own specs with a sbn 44 or 46. Begin with good jet specs. For a single 46, it is: 120 low, 160 main, 2.0 seat, 80gr spring. Jet specs that include an 80gr spring work very well, when converting to reverse specs. Sometimes jet specs get carried away with the low...

The Mikuni sbn and Keihin cdk 2 carbs have a really wide range, when it comes to acceptable main jets. A 5/16" or 8mm id insert swedged & glued into the SBN main jet booster will make it easier to find the correct main jet size because it is easy to find the point where the main is rich. So...

Or possibly a rebuilt crank with Chinese connecting rods. Bill M.

Just make sure you use the o-ring from the Mikuni rebuild kit for the seats. 16 ft-lbs for all the 8mm bolts. I like using a dab of Loctite 515 (or maybe 518) gasket maker, or a little dab of 3Bond 1211, or a dab of ultra silicone on the side of the threads (not on the ends). All of these are...

I am concerned that there maybe something else causing your problems. If you don't find any obvious problems inside the carb like a stiff, or leaking diaphragm, and obvious vacuum leaks (wet gaskets). Maybe there is another problem with the engine ability to produce manifold vacuum (top end...

You might be right, but a reverse jetted 650 sbn uses 2.0, 115gr, 32 psi. pop-off. But if I had the time I wouldn't mind getting a 130gr spring from a ~97' 951 (white engine) and trying it. All you need is the right size low jet (~145). All you need for reverse jetting is a proven good jet...

Looks like what hapens to a JS 550 that ran away, or from jumping waves with throttle on, and in the case of a 550 again; jumping waves without a rev limiter. Bill M. I had a customer try to warranty his F-15 Laser Jet, after he crashed in the waves in front of USMC Camp Pendleton. The...

I am not sure that is a problem. Over the years I have had lots of different brands take a few (2 or ~3) pulls on the throttle before they would rev out. Bill M.

You should replace your cut springs. Either replace them with a 95gr as suggested by Fastgtfairlane, or possibly the stock 115gr springs and (2) 75 low jets. (I have never tried that myself, but it is a safe change that should help starting, idling, and low end response) Bill M.

Use the aluminum parts as a template, and the gaskets as just a visual reference. If you replace the intake manifold/reed gaskets, use the spacer plate, so you don't accidentally cut out the cross over tract. Bill M. Be sure to replace the gaskets I pointed to in the attachment. They are...