blowit

Turn air screws in to .5 turns out and try it. Clean pilot jets Increase pilot jet size. Bike is lean on the bottom B

I would not sweat that a bit. You are not always going to seal at the shaft seals with this type of test. Run it B

Leaking air won't cause any running issues like a lean condition but it will sure leak fuel all over. I would recommend either adding a nut on the top, doing a helicoil, or just get another carb. They are a dime a dozen and I am not sure I would hassle with it. A helicoil would surely work if you do it right. B

I would caution you on trying a carbon rich "paste" product for way of case hardening for a structural application. There just is not enough control of case depth to be accurate. I will admit that getting too much depth would not be a concern with that product but the heat being applied is rarely controlled to any exact science (torch or induction) and that can really cause structural problems. Usually a con rod is made from a carbon poor material so hardening on it's own is more difficult so a carbon rich material must be introduced.

Lets not forget about the Wind CD (coefficient of drag in the wind). Is this with the fenders on or off? IIRC, fenders want to fall off about 110MPH!!! Skinny tires pumped to the max, balanced, no fenders, nose cose, etc. All this can be worked out with math people!! It is just power verses drag. Pretty easy to discover a final gearing selection that will enable a bike to hit the "magic" number but then the drag comes in. I am sure there are plenty of street bike riders here that know how easy is is to tag 120MPH but pushing to say 140MPH gets A LOT harder than say pushing from 100 to 120. That is some serious air pressure. ATVs simply are NOT aerodynamic. B

Gotcha. Let us know how she runs. B

As an engine porter, I would tend to disagree on lowering the ports being easier. It really is about the same deal but I consider raising them easier. You will have to remove all the cylinder studs, relieve the holes again so the gasket will sit down, and deck the cylinders. Not worth it IMO when raising the ports will ultimately be a better deal. Allows correction of some port geometry while also advancing the timing. B

I am confused as to your target. Are you doing a 4mm with the spacer? The spacer by itself will be the same as raising the ports 2mm except your deck height will be all wrong. I think if you do your homework, you will find the spacer is not all that great of an idea because of the stock port map. Also must take into account, the rod length, change in stroke, etc. Why don't you post what your goals are, and your target engine spec and I can make some recommendations. Brandon

Depends entirely on what you are doing to it. Steel con rods tend to hold up extremely well. Hydrolocking never seems to turn out too well though... B

What are you trying to achieve? Do you know the alloy of the rods you are working with? Most all structural components such as rods will be tempered from an OEM for obvious reasons. Most all our our components get tempering free of charge to us because it is like having the potatoes without the gravy. I think I would for go the temper and just use them. Without specific knowledge of the part and alloying, you run the risk of distortion of the precision ground concentricity of the rod centers. Grinding is the last step. Mull Engineering

Those are the carb vents. I suspect someone likes to keep the top of their engine nice and clean... As do I..

You need to make damn sure your slides are not on the wrong sides. Remember that the cut away on the bottom of the slide goes to the back of the carb. Reverse will cause a major lack of air flow at low engine speeds. Mull Engineering

Parking Brake... The PB has a rev limit system built into the CDI. There is a switch on the handle bar that will tell the CDI when it is on. If the PB is not adjusted properly, that switch will lie to the CDI. Simply adjust the PB or bypass the switch and that should solve your problem. I should quantify my statements. The PB may be removed but that wiring still exists in the chassis. Would be wise to find it and delete it. The TORS system does NOT create a rev limit condition, it just kills the bike. Your symptoms are indicative of a PB circuit problem, not a TORS issue. Mull Engineering

Now take a pic of the end of the test end that installs in your head. My guess is it does NOT have a valve in the tip. This is a CRITICAL difference. Usually all those little adapters are a sure sign that you need a different gauge.

It would be a good idea to share specs about your comp gauge or even post a pic of it. I am confident there are plenty of top ends replaced solely on comp numbers that may or may not be accurate. http://mullengineering.com/rt/files/2_tech_docs/THE%20TRUTH%20ABOUT%20COMPRESSION%20TESTING.pdf I did a quick write up a while back on a few of the questions on comp gauges. Mull Engineering

It is very important that you closely inspect the mechanical side of things before you try to sync the carbs. A bad cable, etc will really beat you up. You should be able to get them damn near perfect without s sync tool on a twin. Mull Engineering

Water pump, tits up oring failure where water line sneaks through case, Thats about it... My bet is on the old water pump.... Mull Engineering

The CDI is an all digital, encapsulated circuit so smacking really won't offer much but the plug could have a contact problem. I am reaching for the popcorn to see what happens on this one. My money is on the CDI at this point but who knows. Could easily be a wiring issue... B

Sounds electrical for sure. Stator or CDI. I recommend you meter test the stator when cold, then run it until it shuts off and retest the stator. It may also be wise to just swap CDIs with a buddy and see if it fixes it. Heat related electrical failures are difficult to pinpoint at times. Mull Engineering

Yes, we include deck planing, rechambering, and we mill our proprietary velocity vanes in the squish band for increased burn rates. We sometimes have cores in stock to ship out. I think we have a few here that we will cut as soon as we can get them on a machine.

We charge 85.00 to mod a head for pump fuels and I would put our head against any in the industry. Unfortunately, we are running way behind right now and we are still about 3 weeks out from being able to cut more heads. If you can wait, send it over and I will get it done for you. Brandon Mull Engineering

The tuning parameters of such a thing would be vastly different. In our experience, two strokes require a MUCH different approach than 4 strokes. Mull Engineering

I am not sure what your engine setup is but I would recommend just doing one thing at a time and testing. Doing everything at once will leave you scratching your head if you screw up. Document your results and you will figure out what helps and what doesn't. Mull Engineering

We usually only recommend it to do some testing for final port durations. Use older pistons and file them until you find the sweet spot you want to be in, then replace with new pistons and port accordingly. Mull Engineering