Bridgestone Motorcycle Parts Discussion Board
Bridgestone Tech Talk => 175 & 200 Talk => Topic started by: rdwilroy on October 21, 2016, 07:18:55 PM
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The pistons were not stuck to badly and I was able to free them up. I drained and cleaned the transmission by rinsing with some kerosene, shifted it through all the gears while pushing it around. I Cleaned up the points, reset timing and got good spark on the plugs. I removed the carbs, cleaned internals and got them looking good. Then I removed the heads and cylinders and cleaned them up. One piston has Stuck rings.
So I'm going to get the cylinders re-chromed and got a cost from US Chrome that seems high at $230/cylinder. Is that high? Any recommendations on who to use?
The OD has 2248 miles. Everything seems free in the transmission and crank. Should I plan to split the case anyway to make sure it's ok?
I'd sure appreciate any advice and guidance.
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Try Millenium Technologies for Nickel Silicon Carbide (similar to Nikasil) on the cylinder bores. It's better than chrome and, the last I heard, was closer to $200/bore. Someone with recent experience should chime in here. Cylinders requiring weld repair will be more.
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Why not just buy new cylinders? Jeff bar
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The cylinder's aren't going to need any weld repair so I figured refinishing the bore wold be cheaper? Can you get new cylinders for less? I'm waiting on a cost from Millennium now.
What do you guys think about splitting the case. It seems to shift through all the gears ok, the 4 to 5 speed lever works, I pushed it around in gear and engaged the clutch and that seemed ok. But it has been sitting in a barn for 20 years or more.
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There are no new cylinders, except for a random one showing up on ebay occasionally. I don't think I've ever seen a good usable used one on ebay. They're always junk.
If the rod bearings look OK as far as you can see and feel with the bottom end together, I'd say leave it alone. There can be center seal problems requiring a teardown, but unlikely. However, if there is any sign of crank bearing problems (rust, roughness, etc.), you don't want to risk a bad bearing destroying good cylinders and pistons when it comes apart.
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richard has new cylinders Jeff bar.
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richard has new cylinders Jeff bar.
Oh, sorry, just realized this was a 200 instead of a 175.
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My latest experience with Millennium was very good. Their base price to clean, strip, hone and plate is about $250 each. Any machining, welding, or other services are extra. They will provide an estimate from pics (and stand by it). The last set I had done were in VERY bad condition ($350 each, but that included mods to improve squish and some pretty major welding to restore the exhaust ports) and they came out perfect. As Karl mentioned, the Nicasil will hold up better than the chrome anyway...
...bert
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I used Powerseal USA in Phoenixville PA for my 175. Cost me $200 per cylinder. I live near them so no shipping charges. Awesome results and will use them again.
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Removed engine from frame today. Degreased it and checked the rod bearings. Far as I can tell they look good. Everything turns smooth so I thinking I probably want split the case. I think I'm just take the clutch cover off and see how that looks.
Emailed Richard about those cylinders. Need new pistons, rings and rist pin bearings too. So next up will be stripping the frame down and clean all that up.
Any recommendations on chroming items like finders?
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Pic
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Other cylinder and heads cleaned up nicely.
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Spark plug hole is stripped on one head. I think I've got a helicoil.
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I bought new pistons from Richard only to find out they were to big. Strange that the frame S/N 23A03722 indicates it was a 200. Also the model # on the tag says BS MK/II SS. The vehicle ID on steering neck says MIISS TA1 034620 which if I understand it correctly means it is a 200 made with some left over 175 inventory parts. The cylinder has 177 cc in the casting. I order 200 piston and rings based on the bike being sold to me as a 200 and based on the article I read on how to identify BS models based on ID and s/n's. I'm guessing someone must have swapped the original engine with a175? I didn't even notice the cylinder casting 177 until I found the new pistons were to large.
I have another bike that indicates it is a 200 but have not checked the cylinders yet. I was basically using it as a parts bike since the bike I'm restoring is in slightly better shape. I'm wondering if I should rebuild that engine and put it into the frame that I am currently restoring or just get the correct pistons and stay with the 175 engine that came with the bike. Any recommendations?
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I think it depends on what kind of shape the cylinders and pistons of the other bike are. If you have to buy new cylinders or get them refinished, the expense will be pretty high. From what I've heard the performance difference between the 175 and 200 isn't enough to make it worth a lot of expense, although I've never spent any time riding a 200. You'll have to check with Richard on 175 piston availability, though, if you're going to keep it with the 175 engine.
You can quickly tell if a cylinder is a 175 or 200 from 10 feet away. The 200 cylinders have two round flat spots on the fourth fin (die ejection pin pads), the 175's don't. You can see them in photos of a 200.
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It looks like to me that maybe someone put 175 cylinders on 200 cases? Wouldn't be the first time I've seen it. The pic of your cases above is clearly a 200. The cylinder that you cleaned up is a 175. You can tell by the size of the transfer ports. You could just put 200 cylinders and heads on your bottom end. You may be able to use the 200 pistons that you bought then.
paul
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I didn't know you could put the 175 cylinders on a 200 so I didn't think about that. I'm going to check my other 200 engine and see how usable those cylinders are. Thanks!
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You might be able to confirm that the bottom end on your resto bike is indeed a 200 from the engine number. If you've already done this, just another thought.
...bert
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I was able to unstick the cylinders from my parts bike. They are definitely 200cc. I cleaned them up a bit and tried the new pistons. They wouldn't go in very far without getting stuck. Is it OK to hone these chrome plated cylinders out and try again? You can see from the picture one of them has some damage at the base and exhaust outlet. Looks like someone tried to beat them off or something before. The other cylinder has a little of that as well.
So I slipped the cylinders onto my other bottom end and they fit. I think I read somewhere that 200 cylinders want go on a 175 bottom end but not sure about that. The number on the transmission case on my restoration bike is E817. What does that mean? Doesn't seem to follow the engine numbers for a 200 or 175 does it?.
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Pic of engine case number.
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My guess is that the E817 is the case number stamped on both matching case halves. Is there a similar number on the upper case (or lower since I'm having trouble figuring out which case is pictured). These numbers are to designate cases that were machined simultaneously to assure bore alignment for the shafts and bearing of the crank and transmission.
Maybe Karl or Paul can confirm my hunch. And while your at it guys, where is the engine number stamped on a 200/175? On the rear mount flange on the upper case like a 350?
Probably not advisable to hone the cylinders unless they have minimal damage. A pic or two of the bores would be helpful.
...bert
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Hey rdwilroy,
This is a section from the clymer manual for 50cc-175cc bikes, page 27. It discusses piston clearance.
On cast iron cylinders, the cylinder can be honed to adjust clearance.
On aluminum cylinders, the piston must be polished to adjust clearance.
Hope this is helpful, Steve
Here's the link.
http://bridgestonemotorcycleparts.com/PDF/BS175ServiceManual.pdf
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Maybe Karl or Paul can confirm my hunch. And while your at it guys, where is the engine number stamped on a 200/175? On the rear mount flange on the upper case like a 350?
The cases did have the machining matching numbers stamped on the case halves, but the engine number was stamped on the clutch cover on a pad near the kickstarter boss. Pretty dumb idea IMHO, as damage to that part could cause someone to change it out with another used one with a different number. My 175 HS was originally from Wisconsin, it is titled using the engine number on the clutch cover. Silly.
Which end of the cylinders did you try to put the pistons into? Sometimes the skirt portion of the cylinders gets bent slightly, especially if they are difficult to remove and require some prying. It won't hurt to run a hone through them to remove any burrs, carbon, rough spots, etc. The chrome is just a couple thousandths thick, so you can't do much, although going through all the chrome would take a lot of time and effort. It cuts very slowly with standard hone. Run a hone through them, then try the pistons from the top. Of course, if you have inside mics or a dial bore gauge, just check that way to find the tight spots.
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My guess is that the E817 is the case number stamped on both matching case halves. Is there a similar number on the upper case (or lower since I'm having trouble figuring out which case is pictured). These numbers are to designate cases that were machined simultaneously to assure bore alignment for the shafts and bearing of the crank and transmission.
Maybe Karl or Paul can confirm my hunch. And while your at it guys, where is the engine number stamped on a 200/175? On the rear mount flange on the upper case like a 350?
Probably not advisable to hone the cylinders unless they have minimal damage. A pic or two of the bores would be helpful.
...bert
Looks like the lower case half Bert. The upper and lower cases are stamped with matching numbers on the left rear of the motor. Like Karl said, the engine number is stamped on the clutch cover. For some reason I've noticed that once I've taken apart a 200 the pistons are tight when placed back into the cylinders. I had two sets of 200 cylinders that the bore looked great but the pistons were tight. I don't think I was the initial person who removed the cylinders. What Karl says makes sense about the skirt. I can only guess that wrapping on the cylinder to free it may cause some distortion on the skirt. The one of yours is pretty hammered by the exhaust port and sealing surface. It might not be usable.
Also note that the 175 and 200 heads are slightly different. The 200 head is opened up to the larger diameter of the 200 piston. Don't know if you can run 175 heads on a 200. Again I wouldn't believe it but 175 cylinders will fit on a 200. 200 cylinders will not fit on a 175. The spigot or skirt diameter is larger on the 200 than a 175.
paul
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So the engine# on the clutch cover confirms it's a 200. Evidently someone put 175 cylinders on it.
I ran a hone through both cylinders. Piston drops through the left cylinder now but it has missing chrome at the top. Piston still want go through the right cylinder. Gets hung just above the cylinder skirt. Although the chrome feels smooth, you can see light scoring their on one side and discoloration in the chrome. I might could do some more honing to get it to get through that spot but probably should get it recoated. Any advice?
Thanks for your help!
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Pictures
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Right cylinder skirt
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Once the chrome starts coming off they are not usable. It pretty much looks like you would have to replate those cylinders. Millennium technologies can plate and probably fix the damaged one. I think they run in the $200-220 per cylinder for plating. They have a minimum fee to repair, I think around $275. You may want to see if Richard has 200 cylinders or find some that are used and have them plated.
paul
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If the bottom picture shows the discoloured area of chrome, it may be that the hammering to the cylinder base on the exhaust side has distorted the cylinder. I agree, have them bored true and replated. It should be possible to weld repair the hammered areas. Brian.
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There's a set of used cylinders currently on eBay. Can't tell if the scoring is bad enough to disregard them or not....
http://www.ebay.com/itm/Bridgestone-dual-twin-200-Mach-II-m2-1971-Cylinders-Pistons-L-R-53-08mm-D21-/322124893550?hash=item4b0023cd6e:g:zZ0AAOSwn8FXSNTY&vxp=mtr
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There's a set of used cylinders currently on eBay. Can't tell if the scoring is bad enough to disregard them or not....
http://www.ebay.com/itm/Bridgestone-dual-twin-200-Mach-II-m2-1971-Cylinders-Pistons-L-R-53-08mm-D21-/322124893550?hash=item4b0023cd6e:g:zZ0AAOSwn8FXSNTY&vxp=mtr
Might be a better starting point if the minimum to repair is $275 from Millennium Technologies.
paul
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I had a couple of 350 cylinders repaired by Millennium and they quoted the repairs individually. I think the repairs and machining I asked them to do were less than $275 for both cylinders, so it might be worth sending them pics and getting a price. They were very helpful and easy to work with.
...bert
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Got my cylinders back from millennium. Not sure if I. I'm satisfied with them. I pointed out that one had been beaten up pretty good at the base and exhaust by someone before me, I'm guessing trying to get it unstuck. I told millennium that and sent pics before I sent the cylinders. They quoted $210 for one cylinder with no weld repairs and $275 for the other with repairs. Got them back and damage to the base and exhaust is still there. Called and was told one cylinder had a flat spot and that was the repaired one for $275. They didn't fix the base because they were concerned about possible porosity that could require machining cut that would change stack up dimension or could make the cylinder unrepairable. They should have at least called me about it but didn't. They said there is still good base gasket surface area to seal with. I'm not sure if I should send it back and make them fix it or not.
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Sorry to hear that. It does seem like a phone call before working on it would have been best. :o
Are they able to say that both the base and exhaust areas are definitely functional as returned?
I had 350 cylinders repaired and plated by them, but that was confined to port repairs.
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G I'm not sure if I should send it back and make them fix it or not.
So frustrating when a company does this to you, can feel the pain.
I think it would hinge on, how you worded the original repair (written?) request. If they clearly didn't do what they quoted for, then you may have a case but they do have expert knowledge on their side..(I'm no lawyer)
If they are unwilling/ unable to put things right, carefully take any burrs off the base flange before refitting, shouldn't be too noticeable on the bike. Whether you could get the exhaust flange welded without distorting the replated cylinder, I don't know. Again, providing you can make a seal, not too noticeable on the bike, just irritating when you spend all this money and it's not perfect.
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I'd suggest filing the base to remove any raised burrs, then if needed to get sufficient sealing surface, use JB Weld to fill in, then file smooth again. Millenium was probably correct to avoid welding on that area due to the possibility of creating porosity. Even just filing off any raised burrs, then using a small dab of RTV to fill in indentations when assembling should work.
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these issues and high price is why i said before just buy new cylinders jeff bar
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Jeff - out of curiosity, how much are new cylinders compared to getting a set re-plated? I paid $400 for plating of an undamaged set. And for the money, the new plating is so much better than the old chrome process.
If a new set of cylinders is available for under $400, then you might have something.
Dan
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I had previously had Richard quote me new cylinders for $529. Based on that, I decided to go with millennium, with a better coating. Probably should have gone with the new jugs.
Millennium has offered to take the cylinder back and repair it under warranty. The down side would be if I end up with them making a machine cut on the base that changes the squash dimension or porosity shows up making it unusable. I'M thinking I'll just go with the JB Weld and put it together.
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I had previously had Richard quote me new cylinders for $529. Based on that, I decided to go with millennium, with a better coating. Probably should have gone with the new jugs.
Millennium has offered to take the cylinder back and repair it under warranty. The down side would be if I end up with them making a machine cut on the base that changes the squash dimension or porosity shows up making it unusable. I'M thinking I'll just go with the JB Weld and put it together.
Any chance of finding a used one that needs replating and having them plate it instead of using the damaged one?
Dan
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Maybe but spending more money and introducing another unknown into the mix makes me uneasy. Unless sending it back to millennium for a no cost repair is a sure bet of success then I probably will go back with it as is. If it leaks I suppose I can send it back for the promised warranty repair at that time.
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Maybe but spending more money and introducing another unknown into the mix makes me uneasy. Unless sending it back to millennium for a no cost repair is a sure bet of success then I probably will go back with it as is. If it leaks I suppose I can send it back for the promised warranty repair at that time.
I definitely agree with you on that part. I wonder if that is a concession they would make - you providing them with a "new" undamaged cylinder for them to replate instead of trying to repair the current one that they stated may not be repairable.
Cant hurt to ask.
Dan