Smokey rebuilt 350

[Nurse Julie]

All the piston rings we have had that come in the kits from Cruzinimage for the 400/500/550 and 750 are Riken which are a good make. Not had any CB350 sets from them for yonks, so can't comment on those ones.

[royhall]

Thanks Julie. Yes, there are very few bad reports on the bigger bikes but loads about the 350. I'm suspecting the rings as I have a series of strange vertical marks on the bores. Possibly out of round rings that would also cause the smoke.

[Nurse Julie]

All the Riken rings have a minute letter R stamped on the rings. Difficult to see sometimes but maybe worth looking to see if yours have the R mark Roy.

[royhall]

Cheers will do.

[royhall]

The rings are marked "T" and the oversize on all three rings, no signs of an "R".......... I have a set of Cruzinimage +1 pistons and the rings on that are marked the same. What make would they be.

[AshimotoK0]

The rings are marked "T" and the oversize on all three rings, no signs of an "R".......... I have a set of Cruzinimage +1 pistons and the rings on that are marked the same. What make would they be.

No copyright on marking rings ..you can stamp what like on them. I have Honda CB250K rings from the far east in red Honda packing with the Riken marks on them but they are definitely copies. Buyer beware, spoiling the ship ...blah blah blah. I would go for Genuine, Riken or NPR from a reputable source.

[royhall]

The rings are marked "T" and the oversize on all three rings, no signs of an "R".......... I have a set of Cruzinimage +1 pistons and the rings on that are marked the same. What make would they be.

No copyright on marking rings ..you can stamp what like on them. I have Honda CB250K rings from the far east in red Honda packing with the Riken marks on them but they are definitely copies. Buyer beware, spoiling the ship ...blah blah blah. I would go for Genuine, Riken or NPR from a reputable source.

Do you have a reputable source Ash? Could do with sending them a piston so they can match them up.

[AshimotoK0]

The rings are marked "T" and the oversize on all three rings, no signs of an "R".......... I have a set of Cruzinimage +1 pistons and the rings on that are marked the same. What make would they be.

No copyright on marking rings ..you can stamp what like on them. I have Honda CB250K rings from the far east in red Honda packing with the Riken marks on them but they are definitely copies. Buyer beware, spoiling the ship ...blah blah blah. I would go for Genuine, Riken or NPR from a reputable source.

Do you have a reputable source Ash? Could do with sending them a piston so they can match them up.

Not really ..they seem really rare NOS and hence very  expensive. I have no experience with IMD but perhaps someone on here has, and if they are good quality then worth a try. I notice originals are one piece oil control rings. Perhaps there is a later bike which may fit uses 3 -piece or IMD would probably supply 3-piece. (e.g one model CB125 single rings fit a CB500/4)

[paul G]

Ash,
          I had a set off them for the Z650 about 2yrs ago and all seems well at the moment.
Not the cheapest but seem good quality.

[AshimotoK0]

IMD don't list them . I think C90 is 47mm bore size though or possibly C70 or both. Hairygit will know. I may have some sort of Honda 90 rings at home ..will check tonight.

Hmm think C90 may be 50mm bore ...ST70 is 47mm though.....Hairy ??

[paul G]

IMD don't list them . I think C90 is 47mm bore size though or possibly C70 or both. Hairygit will know. I may have some sort of Honda 90 rings at home ..will check tonight.

Hmm think C90 may be 50mm bore ...ST70 is 47mm though.....Hairy ??

They do carry a lot more stock than just what is on the web site give him a ring.

[royhall]

Just dug out of the pile a new set of Genuine Honda 350F rings, and they have a "T" and the oversize stamped on exactly the same as Cruzin. I guess the Genuine's I have are fake..... They mike up exactly the same size as well, and they look the same...... I guess I need 4 sets of Riken rings in 47.5mm for the oversize...... Alternatively, I do have a set of Cruzin +1mm pistons that I got for free, I may ask Trigger to do a rebore and check the rings at the same time. If he doesn't like the look of the rings I can source some 48mm Riken items....... Am a bit concerned about putting this back together with anything non Honda, but the price for NOS Honda pistons/rings/pins is just too high for what the bike is worth. Also, I will go to the lockup next week and see if I can find the original STD pistons and see what condition they are in. Maybe I could source a set of good nick standard barrels and use those with new rings...... I am well confused with this, not sure which way to go for the best. But I do know that I dont want to be doing this again in a few months so it needs to be right this time.

[hairygit]

Okay, C90 all models from 1977 onwards are 47mm bore and 49.5mm stroke, with a compression ratio 8.8 :1 giving 85.8cc

[K2-K6]

Those rings on the USA bike are more like horseshoes! I'd be worried if I had those.

Like anything manufactured,  you can get a problem occur which is why you'd try to have batch identifications to help pull the affected parts from giving the supplier a poor reputation. If the company policy effectively locks that route off its a catch 22 for the client and you're left to express your findings freely to others.
It shouldn't be like that as other stuff appears to have reasonable views for similar items. They'll shoot themselves in the foot by sticking to that method of selling.

Obsolete pistons and rings are often made in batches to best support slow sales,  it's possible that it could be a substandard batch of rings in supply chain,  but if they won't look at it then not much you can do.

As you say Roy,  to go toward a rebuild with the effort, cost and anticipation that entails,  then it's a real pain with a poor outcome.

[Nurse Julie]

Just dug out of the pile a new set of Genuine Honda 350F rings, and they have a "T" and the oversize stamped on exactly the same as Cruzin. I guess the Genuine's I have are fake..... They mike up exactly the same size as well, and they look the same.

The thing is Roy and it's well advertised all over internet, Riken make piston rings for Honda. I can't imagine Riken making 'to spec' piston rings for Honda and sub standard rings for every other supplier that sells them as Riken, including Cruzinimage. Now, I can understand a pattern part maker making parts that look identical and selling them as such and there is no way we will ever really know if what we are buying really is 'Genuine' or not. It also doesn't mean that the more we pay, the more chance of the product being truly 'Genuine'. Those days are long gone. Agree with Nigel though, could be a sub standard batch.

Edit...as an example we buy OEM indicator stems direct from the same supplier that Honda buy them from in Malaysia. Honda put them in Honda bags with a part number and then charge $$$$$$ more. They all come off the same production line.