blowit

You have something tuned wrong to be putting holes in pistons. Might post up your entire setup from filters, carbs, jetting, pipes, compression, fuel, etc. Something is causing your pre-ignition condition. We usually see this from a lean condition that causes excessive heat and eventually hot spots. Brandon

He is referring to the bolt for the detent arm. It is a 6mm shoulder bolt. i would sure think that bolt was ready to snap anyway if it failed wtih 8 lbs of force. A larger dealer should have it in stock. You can wing it with proper sized shim spacer but doubt it would be worth the effort. Brandon

You added oil to what? The crank case? If so, I could not agree with toasting the case oil from over heat. I too highly suspected the water pump from your description. 1800 is an ankle grab without lube. If I understand you right, a used 4mm crank and a dune port for that? Depending on how bad it popped, you may have made a mess in there and you may just need a top end. If you have what we call "gray matter" in the engine. It HAS to come apart and be cleaned. If you find silver specs on the crank and such, split it. You may only need to clean the crank up. Hard telling but I have caught plenty that seemed locked only until we got the crank out and it was just piston frags binding it. That is not typical though. Brandon

Actually, we have seen a head gasket do the same thing in severe circumstances. The gasket will burn down on the exhaust side all the way to the coolant passage. I will agree that O-rings can almost have a fail safe built in. Like I say, we have not totally wrote them off as junk but they are NOT the best way to seal a super high pressure, high temperature environment. Increasing thermal conductivity with a copper gasket is reason enough to switch to them. We like them. This is in reference to the stock head of course. Pros and cons to everything I guess. Brandon

D, I do have a couple motors out that run 250psi static compression with a pro design head without issues. Those are both 4mm motors. I think O-rings work fine, just do not have any margin of error built in but that is not always a bad thing. A check valve for detonation would be nice. :biggrin: Brandon

' First off, I LOVE your avatar or whatever you call it. The Obama pic. You need to send that to me! I want to hang it with some verbage like " can you answer why you voted for this guy?". Anyway, no one will ever sell me on O-rings in a head. Not saying they don't work and we may very well apply them to later head designs. However, the material properties and surface area make it very hard to bad talk a real gasket. You wanna bash resusing them? Simply buy a copper gasket and reuse the thing 100 times! You won't get that from O-rings. By the way, anyone know what caused the space shuttle Challenger to fall out of the sky in 1986???? It was not a gasket problem.... That being said, we will never cut out an OEM head to add new domes to to it. Why? Because that is too much work when a billet option is pennies away. You cannot fully hide those new domes anyway. Regarding cooling. Adding cooling the a 2-stroke head is like peeing on the back porch while the front door is burning. You need heat for proper 2-stroke combustion. You need cooling in other areas on banshees for sure but we have yet to have someone call and complain that our head blew up there engine because it ran too hot. IMO, either cut the stock head and rechamber like we do or buy a billet design. Brandon

513ps is a wiseco standard bore 513 piston. Both are the same but one just has the old markings. PS is P standard. They used to use p-0 - p-9 etc

Your E-brake circuit is getting you. If as soon as you touch the throttle, it stutters like a rev limiter is set, there ya go. Here is the deal, you probably have a CDI and harness from a newer bike. You will need to get a wiring diagram for the year of harness you have and complete the circuit for the E-brake. It is designed to do exactly what you are describing. Do NOT, pull your carbs, buy another head, rebuild the engine, change your tires, etc. This sounds electrical and I will bet on the E-brake. It does not matter that you do not have an E-brake, there is a circuit in the CDI that if not closed, it thinks you have the E-brake on. Make sense? Brandon

D, I think you know what I was getting at. They don't guess at anything and it shows. I agree, I would LOVE to have the kind of budget they are running with, NONE! B

Not only the tools but the "knowledge" required. Looks like the port finish thing has been beaten to death but what durations are you at with a 1mm raised 1mm? I remember asking a guy a few years ago about a single lung bike of my own that I was tuning up and asked what kind of exhaust timing he liked, He responded with " about 1mm should be about right". He had zero knowledge of my engine state of tune. I knew I had called the wrong guy. You give me any state of tune specs in mms and I am walking. That is for sure. Come to find out through "math" and my own knowledge in the field that the exhaust was not the problem, it was the limited transfer work that was limiting the engine. If I would have listened to him, I would have had to tape my hands on the bars to handle the power hit at 6500. By the way, the max RPM of a banshee is not 6k rpm. I would HIGHLY recommend calling Kawasaki or some other tech schools and take a semester in engine performance and tuning taught by real engineers. You probably think I am insulting you but I spent a week with Kawasaki factory performance 10 yrs ago and you BET I got schooled! I am not sure if you are at that level yet but it would be to your advantage to learn. I went right home and started design of a VFD/roots blower driven flow bench. I could see the glazed look on most faces in the school when they started drawing equations. Some had no business going to performance school without knowing the basics. Ever wonder why the factory race bikes seem to "run" a little better? It's not because they guessed on the port work.

Your attitude probably will not get you far in this business. Customer service is as important to many people as the service itself. As I said before, you have some learning to do before you step in as a large player in the porting business. Do not take that as an insult, take it as constructive criticism from an experienced engine builder. "looking" at ports is only a small portion of the equation. I can find "many" jewelers and pottery people that can put a porting guy to shame with fit and finish of ports with there flex shaft tools but do they "know" what they are doing? If you can find donors, great. I know I would never just dive into someone else's engine without having experience on the subject. The fact that you have not messed with tranfers much concerns me and that IS the largest part of a port job. If you have a banshee, put some hours into it and make it sing. You probably will run into plenty of opposition on this site but how you handle it determines your character and if people will choose to work with you. I don't think you will find too many people to just hand over a set of cylinders for you to practice on. I strongly recommend you "buy" a few used sets and get at it. Just FYI on how we started porting 10yrs ago. We developed some very basic calculators in Excel to determine optimal setups based on "MATH". This is way before we ever touched a cylinder. Only when you fully understand how to optimize performance, will you learn how to make things really fast. You bet there is some trial and error but when we want to test a new concept, we buy cylinders and get to work. We don't just add these new concepts to a customer's motor and hope it works. I have not heard any mention of compression ratios, timing, blow down, etc. These are rather important things. K, I will get off the soap box now. Brandon Mull Engineering

And you are boosting to what?? atmosphere? what are your calculations again? what is boost pressure of your fans? how much power? A pc fan will do what when it gets debris in it? Save the coin and just port your engine. I don't have time to do the math for you but I can assure you it will not work. Sorry. Been there, explored that. About 10 yrs ago.... B

I would ask that you grab some physics books to answer your question. Electric PC fans will do nothing but rob of of HP. How much air do you need your run your engine and at what pressure??? Once you learn that one, you will quickly figure out how much electric power is needed to do much. power in = power out, start with that. B

Not thinking of doing it, yet posted on a forum wondering what would happen????? I smell BS. :biggrin: The give away that you are serious is that you refer to adding bigger jets or piping back to the filter or something. I think you know the answer by now. Not really a good idea. ALL air that enters an engine must be throttled or metered in some way and fuel added.

Me too, me too, I wanna do a port job for free too. I will go get my light saber..... :biggrin: Mopar, I will help as much as possible. The best way to get into porting is to "learn" on your own cylinders and go beat up on some people at the track or hand off some "tested" cylinders to someone that can ride them. It is one thing to make clean paths with a porting tool, but "knowing" what you are doing is a different zone. We have just never leaned towards the "see what this does" logic. I think some more books would be in order. I would recommend, fluid dynamics, laminar flow, venturi effects 101, turbulent air flow and eddy currents, super and sub sonic air flow characteristics 102, thermal dynamics, and maybe a few more. I would also highly recommend a flow bench with custom fixtures for 2 pokes. Insane the knowledge you can gain from such a device. All in all, just saying, I would take the "educated" road and the experience and business will come. How could it not if you know more than the next guy on how to port an engine or should I say the fundamentals of port flow characteristics. brandon

Easiest way is to measure the crown of the piston relative to the deck of the cylinder at BDC and TDC for stroke dim. Most common setups on the pistons was standard con rod and long rod setups. Make sure you determine which you have. You can simply measure wrist pin location relative to piston crown and relay to piston retailer. Brandon

You didn;t really say what your problem is but sounds like maybe lack if full disengagement. This can be caused by worn inner our outer drive hubs of the clutch assy, plates don't freely move in and out of hub assys, pressure plate not opening symetrically due to compression spring issues, and hub installation errors. Engagement problems would be insufficient compression spring tension, pressure plate bottoming due to lack of plate stack thickness, worn plates, or incorrect oil in trans. Car oils will cause clutch slip. Brandon

You can also drill and tap three holes triangulated around the FW center to use a standard wheel puller. Works every time for us. We don't like to destroy our tools :biggrin: OH, be sure to use a drill stop when drilling so you do not kill your stator. Brandon

We noted the test for the ignition coil in some Clymer manuals to be wrong. Secondary is plug wire to plug wire. Your coil is fine. Move on. They rarely fail, just need reterminated and new caps put on. Brandon

Yep, take it apart and inspect the hubs. The basket or outer hub is the most suspect. DO NOT grind on it to flatten things out. Replace it if worn. Many times the plates will have rounded faces on the contact points and this will accelerate wear. In this case, you need to replace the friction plates as well. The steels last much longer. Brandon

LISTEN, the problem likely does not lie in your TORS, but the CABLE. The TORS is doing exactly what it was designed to do and that is throw a fit and protect the rider if the cable or carbs have problems. You need to make sure you have cable play at the throttle lever and sync the carb slides. When you touch the lever and it zings, that means your throttle is partially stuck. EVERYONE wants to remove the TORS because they do not understand it. I agree they can be a pain but they do not fail near as much as people think. The failure usually lies in the cable or carb slide. NOTE, you notice how your bike wants to run wild with the TORS disconnected? It is doing it's job. Put a throttle cable on it and go ride... Brandon

One common failure we have seen is I believe 3rd or 4th gear that tried to weld to the drive axle in the trans. It will cause bind and loss of power until it welds up. We have not attributed this to lack of oil but we think debris in the oil causes it. The banshee does not have a way to filter the oil so contaminates build up without regular changes. You are best to pull the clutch cover and clutch and verify what is locked and go from there. I have also seen them break the shifter system and cause the trans to lock between gears and roast some trans parts. Brandon

As a general rule, we use 10% max as cause to open one up. So a motor that pumped 200psi new would need looked at at 180psi. Personally, I rarely let them get that low before looking into because when compression starts dropping, there is definitely a reason. Most of our motors will hold near new comp right up until rebuild time and the rings are always shot. Keep a log of your ride time and open it sooner than later the first time and that will give you a feel for how long the motor can go between rebuilds. If you stay on top of it, you throw rings and maybe pistons at it with a hone and run it for many years. If you wait, you WILL pay. Brandon

Waiting until the compression drops off for a top end inspection is asking for disaster. We generally direct people to run 50-75hrs on a top end but IGNORE the compression for telling you when it is time. That is only a bench mark because your pistons are not supported like a thumper so the piston can wear out and NOT show in a comp test. I have seen a BUNCH and engines that were hanging on my a thread but showed good compression. Go by hours or time, location of riding, type of riding, and pay attention to your engine sounds and power. You will save your self head aches in the end. Brandon

I already saw your mess in the other post. Buy another motor because flushing that motor is not going to work. You are asking for it. Brandon