Martinm210

WOW! That is pure sickness. I need to wipe the drool off my keyboard! I'd love to see how that RZ powervalve runs...that's awesome!! I've been thinking of a similar project on a smaller scale though. I need something a little bigger for my 6 year old boy, I thought it would be fun to take his little offbrand 110 and start modifying the crap out of it. Maybe some custom arms and swinger to start with, then maybe a bigger motor. I've got a welder, a cutoff saw, and one of those mini lathe/mill combos. It's time to spend some time in the garage!..

check to make sure the stator didn't get all wet and dirty. I just about replaced my stator the other day only to find out all it needed was a good sanding between the base plate and stator. If the OEM can have problems with water/dirt, I'm sure the RS stator can, even more so. Those aftermarket stator covers don't seal very well is what I'm finding..

I just had mine done there, and I can't say enough good about it. I bought a piston/bore kit there through ebay. Mine was a 64.75mm bore that was really worn out. They bored it out to 65.5 and shipped it back with wiesco pro-lites. The work was really good! nice chamfering and my ring gap was perfect throughout. Mine was already ported though, so I can only speak about the bore job. They turned my cylinders around after only having them in hand for probably a day or two before it was back on it's way with a tracking number. I will definitely use them again.

FYI, I figured I'd try one last idea before making my order for an OEM used unit, and it worked. Turns out there was enough corrosion or rust between the stator mounting plate and the stator, that I just wasn't getting a good ground. I took the stator apart and cleaned/sanded all the rust down and put it back together and it worked! Freebee.. After that I spent some extra time sealing up my not so air tight stator cover. Anyhow, if you see a stator problem again, it could just need some cleanup work between the stator plate and the stator. That's all it was for me... Now I can spend a few bucks on upgrades instead of replacing parts..that's good!!

Bummer, and comparing the Ricky Stator to the RMstator product pictures sure does seem they come from the same factory... Here is a Ricky Stator listing picture from the RS site: And the RMstator Ding ding ding...I think we have a match. I guess I'll do some searching for a good OEM. Is it a big deal to buy a newer OEM used stator and simply splice the old 94 plug that I have?

Their ebay feedback looks pretty good. I've been thinking about a use OEM stator too, but considering I have a 94 banshee and the first model stator plug is 87-94, I'm stuck buying a pretty darn old use OEM stator. Having a hard time wanting to buy something used that's potentially getting of age and nearly going to fail just like the one I had, that's why I'm leaning toward a new aftermarket. Are there any recent threads of failures you can point me toward? I did a search, but couldn't really find much on the stator itself. Seems some folks were ok with the CDI box. Not sure, I may just go ahead and run this stator without lights for a while, but I've got another dunes trip in a month and I'd like to have lights for some night run fun..

For whatever reason when I rebuilt my motor, I lost the 12V circuit. Trying to measure 12V on all the wires, the yellow wire coming straight out of the stator when running is not registering anything at all. The black/white wire is reading 7V, but that's one of the CDI box wires, so it appears my 12V circuit is dead. I cleaned up the ground on the stator itself, but still no luck. The bike runs fine other than no lights so I guess the 12V circuit is separate. Anyhow, I spent enough money on the rebuild already and just looking to have a good running bike. Are these RMstator stator's any good. They are pretty low cost compared to OEM, This is just the standard 100 watt version which should work fine for my two 35 watt lights.

Cool, that gives me a number to go by. I will check, just waiting on parts right now. The previous owner just had some hole burning in the piston problems, so I'm always a bit skittish about wondering if my fixes are going to fix it. So far, I found a backward head gasket that was covering about 70% of one transfer port that seemed to indicate one side was getting lean/hot, and I also found what appeared to be a partially failing water pump that I replaced. I also replace the case seals. Since then I had one more break down, but that was my fault for changing the crank and not checking squish. Going to run through the carbs once really well and cross my fingers...hopefully the CDI box isn't the source of the hole buring issues and I've nailed it with this one. This weekend running time per rebuild is getting expensive..:eek:

Cool! I had heard 21s would be fine, but then I read somewhere that you need 22cc's to run pump. My first banshee had a stock head, so this is my first with an aftermarket and domes. I'll just make sure it's fresh 93 pump gas and pull the head again after a short break in as a check.

Now that I just about got my banshee rebuilt for the second time (just waiting for some head o-rings), I was curious about compression. The bike came with 21CC domes and the previous owner ran premium gas in it with success. But...I've recently just had the cylinders bored out and I can already tell that the compression is going to be higher than before with the much improved ring gap. I plan to check out the compression very carefully and was contemplating running some octane boost. But before doing anything, I wanted to get a feel for what was an acceptable compression level for pump gas. Is there a compression limit to where you really need higher the premium octane pump gas? And what about those 104+ octane boost products. Are they safe or any good? Thanks! Martin 1994 Banshee Chozen Perf, 21CC domes +4 Ign Advance Stock Reeds FMF Fatty pipes Ported 65.50mm bore, Weisco Pro-lite pistons. .012" ring gap, .045-.047" squish Hotrods crank

Ring gap should be .010" minimum, but it should be a whole bunch more or it's probably a good indication the bore is worn a bit too much.. FWIW, on my last rebuild I had something like .040" it ran OK until my lack of squish killed both pistons, but the compression was pretty low. Since then I had the cylinders bored and matched, ring gap is now .012". I would do the .006" feeler guage test on one side...that seems like a better means to check. On my bore job, I thought I would be going from 64.75mm to 65.00mm, but I think my bore was soo wore out, the shop had to go clear up to 65.50 to clean it up.

There's really not any good sure method. I've tried flushing with WD-40 on a chainsaw until I thought it was pretty clean, then tore it down to see. It didn't look good, chances are any flushing is just going to flush it into the bearings further. Only real way is to part the cases, but the good news is...you can replace those seals while you're at it. It's good insurance to ensure you don't have a crankcase air leak. Also, the banshee is really easy, no special tools other than a flywheel puller and a 30mm socket. Almost all other case splittings I've done have required heating and pressing of bearings, etc. On those you also need at least and arbor press. Once you've done it once, it only takes a couple of hours to split one.

+1 or you can have a slipped o-ring which will crush the o-ring. I just did this last night and now ordering new o-rings. Careful about the o-ring placement.

The jugs appear to be 102.5mm, so it's not the jugs. I think it's the crank is a special order slightly longer crank. The problem didn't seem to be an issue with the stock crank, so that's got to be it...hard to measure though. I ended up having to go 3 gaskets thick and now have .045 to .047" squish. Like you guys said, the yamabond didn't add up to much of any thickness and with only two I was only at .032-.034" which was too tight for my liking. That extra thick base gasket would have been ideal, but I think these will be ok. They are the thin .015" metal reinforced types and I used yamabond in between the layers. Anyhow, I think it'll be good this time. I have .045" to .047" on squish now. Unfortunately I smashed an o-ring on my head, so I've got a new set of o-rings on order too. It should be here tomorrow then I'll be ready to put the bike back together. Thanks for all the help. My biggest error was rushing things and not measuring and checking. This time I measured and remeasured squish 5 times until I got it right. Ring gap is also measuring a nice tight .012" where previously I think it was well over .030" because the bore was so worn out. I didn't measure compression before, but I will this time.

No, I don't know what was really done before. I bought the bike from a friend, but he bought it pretty much the way it is now with all the work done by the previous owner. The crank was brand new this time, maybe it was one that has a little build in length for extra compression, not sure. I sold off the old crank, so I don't have it to compare to anymore. The new boring is showing much much improved ring gap as well. I think the cylinders were worn enough that I had too much play. Ring gap before was probably .030 before, now it's about .012" with this fresh bore. I tried two gaskets last night and only came up with .030-.034" squish, so I'm still a little short. I didn't use any silicone/liquid type of gasket though, so maybe a good application of some liquid on all the layers will add up a few thousands worth. Regardless, it's odd that even with two of the thinner gaskets that I'm still so tight, there must have been something done to the cyliders, the head, or the crank itself. Something doesn't add up that I need so much base gasket thickness.

FYI, Got my cylinders back from the shop bored out to 65.50mm. I split the case and checked out the crank and cleaned everything up really well. My new cylinder bore job came with weisco pro-lites again, and the same thinner metal gasket that I used before, so I did my first squish check with grease and solder pieces on all four corners with the single thin metal gasket. Of the 8 spots measured, they were all .018" to .020", so I guess I can confirm that 20 thousands ISN'T enough. I'm going to double up on the metal base gaskets which are .015 which should give me around .035" or so and check squish again. I'll report back later...just wanted to update you and say thanks for all the help!

Thanks I'll look that over also when the bored cylinders come back. The weird thing is, the previous build that used a stock crank and standard wiesco pistons didn't have any squish issues like this. So I've been leaning toward either the new HotRods crank, the Pro-lites, or the different base gasket. The previous build did have a thicker paper type base gasket, so it may also have simply been the thinner metal base gasket that pushed it over the edge. That or there is a tiny difference between the stock crank and this hotRods crank. The banshee ran like this for probably 15 or more running hours which makes me think the impact was only happening when running it WOT and for extended periods. This time I'll check squish and adjust the base gasket unil I get to .045-.055. Then I'll check the domes again shortly after running it for some warm up cool down break in cycles.

The crank was a new hotrods crank that was supposed to be stock. I got it as part of the package. Not sure on the cylinders, I know the guy I bought it from didn't do anything with the cylinders. Most of the work that had be done was by the previous owner before him and I have no idea what was done there. When I took it apart, the crank was a stock welded crank, but the outer bearing were pretty rough. The HotRods crank came with the package, so I put it in. This banshee is actually intended for my wife, so reliability is more important than every ounce of HP. I'll make sure it has plenty of squish this time around, that'll make sure I have enough regardless of any minor crank differences. The crank seems to be fine from what I can tell. It was brand new except for this one weekend excursion. The piston failure didn't occur suddenly or with any sort of sudden seizure, so I'm hoping these stresses and failures were all smaller impacts that wouldn't have been enough to damage the crank. The bike actually would start with these pistons like this, but it was only really firing on the right side cylinder that still had decent compression. Anyhow...all new to me. I did know better about squish. I've checked it before when rebuilding some chainsaws recently, but I didn't know what the banshee should be and was in a hurry to get it running before our dunes trip. Oh well. Education is never free...at least we had pretty much a full weekend on this first failed build and I'll be meticulous about squish bands in the future...

I think there was too much clearance also, this is why I'm sending the cylinders off to get bored this time. Ring gaps was looser than what I wanted to see, but I threw it together anyhow figuring that it ran before, so it would be ok again. I guess this problem could have been a combination of the two, squish and too much clearance. When the piston is slightly rocked, it would extend further into the domes on the high side making squish a bigger problem. This time I think I'll check squish very carefully, do some break in heat up cool down cycles, and then pull the head to check. It's pretty obvious when there isn't enough by the rings that develop on the pistons.

The previous build used the same Chozen Performance head, but it may have had a slightly thicker paper base gasket. The base gasket I used in this last build was one of those thinner metal Wiesco kit gaskets. I don't know what the squish was though, I never checked..obviously was too little.

Awesome, thanks! I'll be checking this very carefully this time...

I recently bought this 94. It had a hole in one piston, so I went through the motor. Found what looked like a partially siezed water pump bearing, and backward base gasket covering up the failed piston side. I ended up replacing the waterpump and bearing, installed all new bottom end seals, new crank, and and bought new Weisco Pro-Lite pistons. I think the last pistons were standard weisco pistons. Anyhow, a weekend later it gave up and would only run on one cylinder. Took it apart and found one piston had partially broke, but closer inspection it appears both were having squish/impact problems. Not sure if it was the gasket, the pro-lites, or the crank that was ever so slightly different. The old melt down didn't appear to have any problem with squish, just melted a hole which I think was due to the waterpump and/or that base gasket covering up half a transfer port. So on my round 2 rebuild, I'm sending the cylinders in to get bored out. I think the old bore was a bit worn which may have been part of the problem. Anyhow, here are some pics...too little squish is apparent. So...how much is right? I'm definately checking this next rebuild. The banshee is a 94 with a Hotrods standard crank, cylinders have been ported (will be going up to 45.00mm), the head is a chozen performance head (not sure which domes, but supposed to be the max for pump gas), FMF fatty pipes, K&N filters, +4 Ign. Adv. The bike ran awesome when it ran, but I definately want to check and set the squish properly this time.. So my question is: How much squish should I have with this setup? Do you think the dome in the picture is still ok? Should I polish it or anything? The marks left are very shallow and don't appear to be enough to cause a problem. I've got the case split right now to clean out all the little bits of aluminum and the cylinders are already off to get bored and matched to some standard weisco pistons.

That's what I did, only seemed right since that's where it would get it's oil from.