mondtster

Sounds like a plan. I'll look forward to seeing some pics of yours once you have it finished.

If inspecting your carbs doesn't fix anything I would be looking for an air leak somewhere between the carbs and the motor. You could possibly have a torn carb boot or a balance tube (or boost bottle) that got ripped off, etc.

I agree, but I just thought I would mention it since he is working with an unknown motor. It is easier to investigate things first rather than pay for something later that could have been avoided. Honestly, I'm guessing that you are right but there is only one way to tell...

The domes may be a band aid for a worn out top end though so I would do a compression test to see what it comes out at. They may also be there if there is some other work that we are unaware of that would lower the compression as well. Bottom line is that a compression test needs to be done as well as further investigation to see what you really have. My buddy bought his 'shee which he thought had a stock motor but he ran into similar issues and found out that he had a long rod motor and with the way it was built required either 17 or 19cc domes (I can't remember right now) to reach the upper limit of compression for pump gas.

Care to share the information pertaining to the conversion with me? It doesn't look hard to do from the few pics I have seen, but figure that if you have done it or have more information regarding it I could use it...

An even easier way is to use a GPS if you have access to one. I found that I was actually several hundred feet higher than what was claimed by all the other information I had access to.

Check the tranny oil level. I've seen them puke oil all over from being overfull. If you just bought it I would also suggest just replacing the tranny oil and making sure the level is correct. If you still have problems after that I would start investigating further at that point.

So we agree then. All I am trying to get across is that you will not get any more power from running higher octane fuel than is required. I don't care what you are required to do to get adequate fuel in your country. Besides, what you are saying now wasn't said in your original statement. Am I supposed to mind read and see that you are in a place that doesn't have adequate pump gas? Just my $.02...

I agree, but I also believe that most 15 year olds don't truely understand preventave maintenance to the same degree that an older, more seasoned rider may understand. In the last 10 years I have learned a lot, and I can tell you that most people my age still truly don't understand the 2 stroke engine much less have the ability to work on them correctly, and I am 10 years older than him. This is just my opinion. I am not trying to bash anybody. I am just trying to make him aware that he isn't just in for an occasional piston and rings swap from time to time like he may be with a relatively stock banshee. BTW, I would stay in school kid. $30k isn't much when you get into the real world and have to pay for all your own stuff.

You can use Duncan's suggestions as a starting point, but I would always do your own research on jetting. Altitude, temperature, and modification differences between your motor and the motor they based the suggestions off of can and will cause each individual bike completely different. For example, your bike may run fine (and not blow up) on Duncan's jetting suggestions, but I bet it doesn't make all the power it could make. Manufacturers generally play it safe and err on the fat side for jetting so the motors live.

I'm not trying to bash him, I just want him to be aware that mainenance will be an expense that he needs to budget for. I can tell you that there is no way I could have afforded to put together a motor like that and maintenance it correctly when I was 15 or 16 unless my parents would have helped me. I wasn't working minimum wage jobs either...

I understand fully. But why do I want to spend the extra money to get high octane fuel when I can realize the full potential of my current setup using pump premium? I won't gain anything by switching to 110 octane fuel and leaving everything else alone...

The simple answer is no. To expand on that, the service shop guys (at least around here) don't ride your machine or really check to make sure it is jetted correctly. They just do what the instruction sheet that came with the pipes or whatever they are installing says and hopes it is ok. Generally speaking, they also don't really care if it blows up or not because it isn't their machine. IMHO, learn to do all service work yourself. If you own the machine you had better be able to do at least basic maintenance because the machine will break at the least opportune time and you'll have to figure out what to do then.

You do realize that you aren't going to gain any power simply by switching to higher octane fuel right?

So you're going to dump all your money into a motor huh? How are you planning to pay for the preventative maintenance on such a machine? IMHO, building a motor is not a one time expense but a commitment that will cost lots of money over the life span of the motor. What happens when you burn the motor down because of an air leak or poorly adjusted carbs? I've seen too many projects sit for too long without use because people bite off more than they can chew. My prediction: This banshee will be up for sale in a year or two because it is so screwed up that it will cost you too much to repair (if it ever even makes it that far). Then somebody will get a pile of decent parts to put a quad back together with.

By buddy's bike fouls plugs quite frequently now that he switched to a cool head when it was fine before. It isn't with tuning either because jetting is spot on. The only thing different with his motor from before to now is the head, so I believe that we can safely blame that for the increased amount of fouled plugs. I'm mentioning this because it may be worth a look for you since you mentioned that you are running a cool head.

Well, I would be pulling the side covers off first and seeing if it happens to be something easy before ripping into the whole thing. I honestly hope I'm wrong for your sake and that you will get away with an easy fix.

That's the one! Thanks for providing the link.

I think you would be amazed at the amount of oil that pools in the bottom of a 2 stroke engine crankcase... That is why they smoke so much when you start them for the first time after they have been sitting for a while. There really isn't a lack of lubrication in one of these engines especially considering that we are talking about needle bearings. IMHO, I know there are a lot of people who don't understand how the 2 stroke principle works, but google is your friend and there is an animation somewhere on here that shows the 2 stroke principle. A little bit of searching goes a long way.

I've always had pretty good luck with them so far, but I also always have a paper catalog of theirs with me when ordering over the phone or online. The paper catalogs seem to do a better job at describing the parts being ordered than online in my experience. The other thing that I would suggest is to go to your local dealership. All the ones around here get their stuff directly from parts unlimited (dennis kirk is parts unlimited's consumer outlet) or tucker rocky and are right about in line with what you would be paying from dennis kirk.

I'm betting that you will have to split the case. I am somewhat new to banshee specific tranny issues (I haven't personally had to deal with any yet on any of the banshees I have worked on) but I'm guessing that it is either a shift drum or shift fork issue based on past experiences.

I wasn't worried about your question, I was just making a statement. No worries...

IMHO, if you have to ask how hard it is to do then you probably shouldn't attempt it yourself without some experienced supervision.

I think you're going to have to split the cases to inspect it. My old YZ125 lost a tooth on one of the tranny gears (I can't remember which gear but who cares?) which wedged its way into the shift drum in the tranny. It would stay in neutral and you could kind of get it into first depending on how hard you tried to do it. The other thing running through my mind is the possibility of a bent shift fork. Was the banshee recently wrecked or something that may have affected the shift lever?

I searched for what I was looking for when I first came here, so to me searching is a common sense thing. That is why there are sites such as google and search functions on pages such as this. Sorry for the thread hijack...