blowit

Sure sounds like the floats are in upside down which will cause no fuel flow to the float bowls. You are not getting fuel. If that checks good, better clean the pilot jets again. Brandon

Basically what was said above is cutting on ports while having no idea what is is you are even cutting on, why, or what it does, is certain for disaster. An understanding of the concepts is a much safer approach. If you can't tell, we prefer to do things by the numbers because numbers do work. I guess in some other work we do, "that's about right" causes aircraft to fall from the sky. We don't leave much to chance. This also does not mean you need a degree in physics just to port cylinders but the more you know, the more armed you are. Brandon

Guys, we have had so many guys ask and have replied too many times. Thought it warranted it's own topic. To port yourself, you do NOT need any specific tools but ones that will work for you and obtain a certain goal. What I mean is after you know how much material it to be removed and at what level of finish, you can select what tools you want to use. Some guys use air tools, some guys use electric, some guys use a wood chisel, does not matter as long as you know what needs to be done. You should understand what you are doing BEFORE cutting! Porting was originally concepted by engineers to change optimal power characteristics to tailor power in a certain area without having to recast a cylinder. The actual tuning of engines from the basic concepts IS brass balls engineering but some of the best porting masters have learned through many hours of studying, trying, and failing. Absolutely anyone with capacity and desire to port an engine, can do so with success. The key is in the homework. This seems to be where most will fall short in that by simply looking and measuring ones work, they can simply "duplicate" it or guess on the measurements and "that's about right" theories. There is a ton to be learned in porting and it can be fun and rewarding. The biggest to note here is learn. I will say this, if you are not good at math, things can get tricky and confusing fast. Engine porting is about 95% math. Hell, engines in general is 98% math. After all, do you think the OEMs just "guess" on the size of a bore, stroke, rod, comp ratio, etc? Learning the basics just makes you more educated when assessing porting. "Porting" or port flow and timing are things that should be look at both together and separate. The idea is to get more dense fuel/air in the combustion chamber without losing a bunch out the tail pipe. This all works off port flow in CFM, CMPM, pr whatever volume you wish. Obviously, longer you leave the door open, the more you can get through it in a given about of time. The key is how long is too long? These are questions that only math can answer. By guessing at porting, you can leave yourself wondering, "what did I do right", or worse yet, "what did I do wrong". Timing is one thing, individual port flow is another. Understanding port flow has less to do with engines and more to do with understanding sonic and subsonic air. For these concepts, we HIGHLY recommend starting with fluid dynamics and aerodynamics books. Some of the theories seen in old engines are considered "old school" by todays standards due to better test data and testing methods. Simply understanding flow means you can actually improve an engine by simply helping ports to flow better. I will not drag this one out as I am hoping others will elaborate but the one thing you cannot have too much of is EDUCATION. Read it and understand it. If you think any porting expert got there by guessing, you are wrong. Sometimes it does take trial and error to prove a theory. We call that R&D. It takes time and expense. For anyone wanting to port their own engine, please understand that you can do it, but guessing will get you no where. There are a few amature porting guys here that actually know what is going on. Props to them for learning it. To anyone looking at learning porting, understand that it is NOT an "art" as some people call it but an expertise in an area few choose to learn. After all, find me some true art that had an intended goal when it was concepted. Porting is math and physics and it can be learned. I recommend to anyone looking to understand porting, get books! This will certainly lead you down the path of success and understanding. Brandon

Tell ya what, I will post a new one for you and others looking to self port. We are not against it at all but education is key. Brandon

YOu really need pipes that work with the porting. Using high rev pipes with low rev porting can spell problems. guess we have never tried it but the theory of flow and physics does not work. I am wondering where you are going on the bigger bore. That would not change the duration but I might be reading that wrong. Brandon The best performing woods bikes we have over done included either injection or the 1-2 intake with single carb and 2-1 pipe with woods porting. damn near rip your arms off but super fun to ride.

If you can enclose your engine build and tune, I can recommend a better setup. Ours typically holds 80HP with a near OEM clutch pull and over 100HP with about a 30-40% increase in tension. I have worked with super tough clutches and they are ridiculous IMO. One of the reasons we made a clutchless shift kit. Brandon

If you are wearing woods porting, the port work is probably what is holding you down. Kinda have to take from Peter to pay Paul. Durations have to be held down for bottom end grunt and that will set a lower RPM max torque curve. Brandon

If I remember right, we built that head for you. Anyway, you are spot on with what we would do. You may be able to push timing just a bit more with 93 but honestly, I doubt the extra 1.5 will be worth the fuel expense. I would look into other mods before flipping to race fuels. We generally push for race fuels but sometimes, convenience is king. Brandon

No sir. Regs are for lighting only. Brandon

Should be able to carefully remove the threaded part of the jet from the emulsion tube. Should not be a big deal unless you pulled the threads out of the emulsion tube. Brandon

That is pretty much, where I was headed. can't tell you how many times we made the decision to split them and found "hiding" debris on there. You can just never be sure. In our business, we have to do it because when you have crap in the bottom end, the bearing condition must be assessed. Brandon

You are just going to push funk into the bearings. If you have problems, I recommend brake cleaner with the little tube in the oiling holes and paper towels. If that don;t do it, split em. Now that did not sound right. Unless you are a 5'10 blonde with ID hardware. Brandon

I would say someone needs to go back to school if they are saying rings or valves would cause this. I am aware it is a thumper and yet again, the carb WILL cause this. There is a pumper or accelerator pump in the carb and can fail and way over pump fuel to the engine. This should cause it to run like crap though. IS it possible you have it way over full on oil? They are tricky to fill. DId you read the manual when filling? We have seen it toooo many times where a guy will over fill and it is easy to do. Brandon PS, just to clarify, I am more worried about the fuel seeping in when not running. Really would not make it by the rings while running unless motor is shot.

That statment is dead on. The get closer in accuracy, the bore size and dome volume from timing edge must be calculated. The dome can change everything. Since you are in CAD work, get some measurements on the some and figure the volume of it and put that in the equation. You also should figure the gasket if using one. If you can post all the specs like port height, piston height relative to deck at TDC, bore, and so on, I will check my numbers. We always use correctly because I feel that is the only true way to do it. Uncorrectly just makes little sense to me. You port your engine and comp ratios does not change? BS It sure does. This gets much tougher with thumpers but worth the efforts when building. Good job doing your homework and taking time to check things out. Brandon

92oct will do you fine if you want to run it. Otherwise, I would buy the 100. Brandon

Carb issues if you are sure it is not coolant. You should easily be able to smell what is going on. Gas ain't good and will toast your motor quickly. You may look at your float level, needle and seat, and pumper adjustments. Brandon

Not tryin to be Mr. Ass here but you need to read up on oil compositions relative to their respective mix ratios. I will include a link from my site but there is much more info out there regarding oils. The mfg recommend ratios based solely on their oils tested. Full synthetics can work with much high ratios and still protect the engine. We have our own data on oil testing but there is plenty of test data out there regarding ratios with certain oil types. http://mullengineering.com/t2.cfm?q=qna Brandon

Thats the kind of compression we like to see. She is not going to sign off with 190 psi static as long as timing curve and air flow are working for you up top. The last one that went out our door pumped up 260psi! Brandon

10-4 or blaster pistons but they are actually relocated a little over 5mm and dome is different so not as common any more as the 795s

I am not sure how you are installing but if you are requested to use the overflow tube on the bottom and eliminate the overflow tube in the bowl, don't do it. This can cause fuel to fill up the crank case of the carbs overflow. You need an overflow. We always tap the bowl with an insert and leave the stock stuff alone. Brandon

I agree on alky. So much fuel being dumped and vaporization of the fuel is just so much better with higher pressures of injectors. Just getting all the slick features while holding the price down is going to be tough. Injection is just the only way to fly with boost and NOS so for full race guys, it is a no brainer but the simplicity of carbs is still appealing to many. Brandon

sho looks like cold or hot seizure from here. I can faintly see the signs on the piston. One sided at that. I would want to check piston clearance on that one. The extra stick can cause you to rip the end out of the rod but that is not common. Brandon

I think the Pro x uses OEM tolerancing so the book will tell you. I want to say .0015 clearance but it has been a day or so since using cast pistons. Brandon

absolutely. By auto enrichment, I just mean no choke lever. That was something Honda piloted years ago with the CBRs in the bike world. Still an open loop system with 02 verification. Wide band opens many doors but lead and alky create problems. Yeah, I have not put a tone of thought into it but I know OEMs cannot induce closed loop until operating temps come up and proper combustion commences. Just too tough to stay closed when your burning half the fuel charge on start up. I am sure the OEMs know what they are doing and have put plenty of thought into all possibilities. I still think 02 sensing will go out the door shortly. Brandon

That is kinda what I was getting at. There are other means to employ closed loop data input but the EGT as a closed loop input parameter can work if tuned correctly. The only things we look at hard for this are fail safes and without closed loop, a system can fail without without indication. There are many ways to do it but we feel CL operation is the only cold start enrichment is the only way. brandon