Like others have already said it sounds like the piston is on backwards. The newest BB kits that I've seen look, and run pretty good, the older kits had lots of issues. I'm sure Bailey's will do what they can to help you out.
New Baileys BB kit not a very pretty sight
- Thread starter atlarge54
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gink595
Addicted to ArboristSite
As I was looking at it last night, the ring locater pin is center of the bore perpendicular to the wrist pin, I don't remember which way the arrow was facing now but I believe it was correct the pin was towards the intake side, after thinking about that later on I don't believe the piston ring would ever enter the intake area anyhow so that might be okay on how it is, I just have never seen a piston that located it's rings there in the center??
Also the Nikasil coating was thin near the decomp hole along with it looked to me like tooling marks in the upper part of the cylinder that penetrated teh nikisal coating, I could catch my finger nail in it and there was 2-3 of those. Another horrible looking thing I noticed was the upper transfer they were not aligned and not symeterical at all, the one transfer was only about 3/4 open blocked off with cast compared to the other side. All around this was not a very nice cylinder and I agree'd with Atlarge that he should either try another one or go with OEM.
I forgot to mention this also, but the Nikisal stop short of the squish band by about a good .125, someone else pointed this out to me on a 372 BB kit and it is the same with this kit. I don't think this would affect 99% of people but for the guys milling the base of the cylinder to do pop ups and such might get a ring snatched up in there.
I snatched this photo from Skippyktm in a thread he had, I noticed his had this also, you can see teh darker ring near the squish area, that is what I'm talking about, and you can put your fingernail in it and feel the thickness difference.
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There are several saws that have one ring, and it ends right in the middle of the intake port. It never drops low enough to enter the port, so is not an issue. The stock 7900 is the same way. The 441 has one in the middle of the intake, and the other to the side of the exhaust.
I believe the decomp hole is above where the rings ride. Same with the area where the NiSi stops. It would be nice if it went to the top, but OEM doesn't even do that a lot of the time. These are designed to be bolt on replacements for the average user.
Could you get us some pics of the transfer port?
So far, I don't see anything that would affect usability. It's kind of like the "chicom" 260 P&C. No, it wasn't perfect, but it wasn't anything that would hurt performance. It's just a quality of finish issue. And I do expect more from OEM.
I believe the decomp hole is above where the rings ride. Same with the area where the NiSi stops. It would be nice if it went to the top, but OEM doesn't even do that a lot of the time. These are designed to be bolt on replacements for the average user.
Could you get us some pics of the transfer port?
So far, I don't see anything that would affect usability. It's kind of like the "chicom" 260 P&C. No, it wasn't perfect, but it wasn't anything that would hurt performance. It's just a quality of finish issue. And I do expect more from OEM.
bayshorecs
ArboristSite Operative
Just got my BB last night and noticed the exact same things.
The ring pin is in the center of the intake, the OP had the piston backwards.
I also noticed a lip in the top of the piston which conerned me, but this is my first rodeo so I didn't know if that was a problem.
I also noticed the "line" in the ports like the above pic which I assumed was from tooling. did not know if that would cause an issue.
Not that it is a big deal, but I bought the gasket separately assuming it did not come with the kit based on the description "Gaskets are sold separately." and it being recommended when you purchase the 6401 + BB kit combo (just checked, and it looks like the description may have changed since I ordered the parts). The kit included 2 gaskets and the thinner metal gasket measure about .019 which was the same as the other one I ordered. Only a couple buckets, no big deal. Will keep the other as a spare.
I might try to get some pics of mine posted too.
The ring pin is in the center of the intake, the OP had the piston backwards.
I also noticed a lip in the top of the piston which conerned me, but this is my first rodeo so I didn't know if that was a problem.
I also noticed the "line" in the ports like the above pic which I assumed was from tooling. did not know if that would cause an issue.
Not that it is a big deal, but I bought the gasket separately assuming it did not come with the kit based on the description "Gaskets are sold separately." and it being recommended when you purchase the 6401 + BB kit combo (just checked, and it looks like the description may have changed since I ordered the parts). The kit included 2 gaskets and the thinner metal gasket measure about .019 which was the same as the other one I ordered. Only a couple buckets, no big deal. Will keep the other as a spare.
I might try to get some pics of mine posted too.
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bitzer
******** Timber Expert
Like Brad said there doesn't seem to be anything that would effect the useability of the cylinder. Did you measure the squish? Without a gasket my squish is at .023, with the gasket more like .045 or so. I don't think the ring would even ride high enough to worry about the lack of plating. Is it ideal, no, but they are good quality for a hell of a good price compared to OEM. Pics of the transfers would be helpful. Contact baileys and take it up with them.
If squish without a gasket is .025", and crown thickess is .130", then the NiSi could be .155" from the head, with no problems.
bayshorecs
ArboristSite Operative
Here are some pics:
Just called Baileys and just as suspected, new one on the way. I should have asked if they might give the replacement at least a visual inspection before shipping. To anyone not familiar to doing business with them I highly recommend giving them a try. Hey Grande Dog if you're listening maybe take a peek at some of the BB kits.
Brad I measured .125 from crown to top of ring add .050 squish for .175 total. The decomp hole is about .200 from the bottom of the hole to the top of cyl. On the intake side of the cyl. the shadow region of the nikasil is at least .250 from the top of the cyl. The ring will definately get into some questionable areas.
The real issue is the major nick visible to these 58 year old eyes without the aid of glasses.
Also correction, the piston ring pin is located on the intake side.
I'm beginning to believe that the large squish numbers being reported for these kits may be intentional to keep the ring in a safe zone. It seems from a manufacturing standpoint the upper portion of the cyl. is tougher to maintain bore quality and plating.
If my living depended on this saw I'd without a doubt buy the Mahle P/C. However for my level of use the econo version will be workable. With a little luck I might have an 84cc saw with a 20" and 24" bar plus 4 new chains for about $400. Only time will tell.
Brad I measured .125 from crown to top of ring add .050 squish for .175 total. The decomp hole is about .200 from the bottom of the hole to the top of cyl. On the intake side of the cyl. the shadow region of the nikasil is at least .250 from the top of the cyl. The ring will definately get into some questionable areas.
The real issue is the major nick visible to these 58 year old eyes without the aid of glasses.
Also correction, the piston ring pin is located on the intake side.
I'm beginning to believe that the large squish numbers being reported for these kits may be intentional to keep the ring in a safe zone. It seems from a manufacturing standpoint the upper portion of the cyl. is tougher to maintain bore quality and plating.
If my living depended on this saw I'd without a doubt buy the Mahle P/C. However for my level of use the econo version will be workable. With a little luck I might have an 84cc saw with a 20" and 24" bar plus 4 new chains for about $400. Only time will tell.
I can't see any quality problem in the pics you've shown. Can you get a pic of the transfer port questions?
.050" squish! Why? It should be more like .020"-.025". Are you using that thick spacer? That's for use with the Solo 681 since it has a 1mm longer stroke.
I believe Grande Dog said some of what looks like lack of NiSi, is actually where it wasn't finish honed as well. Maybe he can jump in here and clarify.
mtngun
Addicted to ArboristSite
Thanks for the more detailed explanation, atlarge54. It does sound like the manufacturer is still struggling, but at least Baileys is taking care of you.
As I understand it, the squish band is machined into the cylinder after casting. The cutting tool would have to rub or nearly rub the side of the cylinder, which could explain the imperfections at the top of the cylinder wall.
No one wants the QC fixed on these kits more than I do. The kits are an awesome concept, if only they'd get the bugs worked out.
As I understand it, the squish band is machined into the cylinder after casting. The cutting tool would have to rub or nearly rub the side of the cylinder, which could explain the imperfections at the top of the cylinder wall.
No one wants the QC fixed on these kits more than I do. The kits are an awesome concept, if only they'd get the bugs worked out.
gink595
Addicted to ArboristSite
bayshorecs
ArboristSite Operative
Thats becasue thats not Atlarges pictures
Trying to get some better pics from inside of the jug uploaded. I don't think I have any problems, just might help the other guy compare against his.
Thats becasue thats not Atlarges pictures
I missed that. Pics would be nice if we're going to document an issue.
From what I've seen, the greatest issues with the WoodlandPro kits has been combustion chamber/squish shape, and exhaust port shape. Many kits are showing up where the squish is tapered reverse from what it should be. In other words, it's tigher at the edge of the combustion chamber than the cylinder wall. Some have been bad enough to be unusable. They actually hit. Those were all pitched. The last ones I saw have a beautifully machined, perfectly shaped squish and combustion chamber. I'm talking a work of art here! They are improving.
The next biggest problem is the exhaust port shape. Most are either flat, or even convex. They really need to get a curved exhaust port roof and floor if they want to avoid catching rings.
I so desperately want these kits to be what they can be. There's no reason these kits can't be cast with close to ideal port timings and shapes. This last 066BB is nearly there. Widen the intake port and you'll have a screamer. A modder's going to want to widen the transfers as well. I've given a fair amount of input on these kits, and I've seen some of it become reality. Unfortunately, these changes take time. That's just the way it is.
smitty299
ArboristSite Member
The squish on mine was .051 with the thin gasket and ended up at .031 with no gasket comp is at 165psi and it runs strong. mine also has the combustion chamber shaped wrong the squish is .031 at the inside at the cyl wall its something like .04? 
Brad I'm just assuming the mfg. sends a base gasket that's meant to be used with the saw the kit is designed for. Less squish, less compression, less stress more safe zone at the top of the cyl. might all add up to fewer problems. This all comes at a price which is reduced performance. For a bit more than $100 to pick up 20cc displacement isn't too bad if everything stays together.
As you probably already know those weren't my pictures. I had my camera out and was unable to get any detail of inside the cyl. My camera is a decent new Canon but only a 6x zoom. Evidently a higher zoom is required.
Possibly different lighting techniques. What are the guys using that get nice up close detailed shots?
I'm a relative rookie here trying to learn a little. I'll probably never use a stopwatch and a chainsaw together. My attention is more towards keeping all body parts firmly attatched.
I would guess that you're probably not using the macro mode. That's what you need, along with good light.
gink595
Addicted to ArboristSite
WHAT!!!! Thats disguisting
I wish the airfilter cover had a stopwatch built into it...LOL
WHAT!!!! Thats disguisting
:agree2:
Grande Dog
ArboristSite.com Sponsor
Howdy All,
It took me a little while to respond because I needed to do a little research This is in no way to diminish the issue at hand. Here's the box score on the BBN 7900 We've sold 358 and have had 2 returns. The one we're talking about here hasn't been added to the report yet.
The honest truth is that I have to deal with the biggest issues first. The vast majority of the time it's the money lost, or not being made that drives the urgency of the issue. Recently I've been devoting a lot of time to the BBN 066. It's our best seller by far and demanded the priority attention. I can tell you that the newest generation going into production is nice. We still don't have exactly what we want but, it's getting pretty close.
Our goal is to have close to OEM quality at half the price. Are we there yet? Not even close but, we haven't lost focus through the trials and tribulations. I can't remember the last time that we did a production run that didn't have improvements. The folks that manufacture for us will make the changes we request to the molds for free but, our minimum order quantities go up. It's a good news / bad news scenario in that costs are pretty stable but, there are longer periods between production changes.
I have seen some cylinders with the ring at the top that looks like it wasn't coated. I'm sure that they're coated because you can see that the coating goes way into the combustion chamber. The hone just didn't reach the top of the cylinder.
I hate to not finish this train of thought but, I gotta go. I'll be back.
Regards
Gregg
It took me a little while to respond because I needed to do a little research This is in no way to diminish the issue at hand. Here's the box score on the BBN 7900 We've sold 358 and have had 2 returns. The one we're talking about here hasn't been added to the report yet.
The honest truth is that I have to deal with the biggest issues first. The vast majority of the time it's the money lost, or not being made that drives the urgency of the issue. Recently I've been devoting a lot of time to the BBN 066. It's our best seller by far and demanded the priority attention. I can tell you that the newest generation going into production is nice. We still don't have exactly what we want but, it's getting pretty close.
Our goal is to have close to OEM quality at half the price. Are we there yet? Not even close but, we haven't lost focus through the trials and tribulations. I can't remember the last time that we did a production run that didn't have improvements. The folks that manufacture for us will make the changes we request to the molds for free but, our minimum order quantities go up. It's a good news / bad news scenario in that costs are pretty stable but, there are longer periods between production changes.
I have seen some cylinders with the ring at the top that looks like it wasn't coated. I'm sure that they're coated because you can see that the coating goes way into the combustion chamber. The hone just didn't reach the top of the cylinder.
I hate to not finish this train of thought but, I gotta go. I'll be back.
Regards
Gregg
Thanks Gregg. Your input is appreciated. Above is what I was referring to earlier.
