Hey, RD400 guys...

[85RZwade]

My buddy has a 76 RD400 project he's building, and somewhere along the way he acquired a set of cylinders with, supposedly, Banshee sleeves installed.
1) is this possible, probable or maybe even common?
2) if so, why would it have been done?
He's got a set of stock cylinders as well, and we're talking about which set he should bolt up when the time comes. Thanks!

[Striker1423]

I thought the cylinders  on RD's were not sleeve able?

[Seizer]

Would shit even line up?

[rd400canuck]

When I spoke to CVTech-AAB in Quebec about the cylinders that came off the bike I bought (I discovered they were wore right out and ported by a monkey) he said I had the option of resleeving them. I never bothered as I found some from a member who is on this forum.

Maybe give them a call and see what they say.

[m in sc]

maybe because they were readily available? who knows. pics would tell the tale.

[SoCal250]

I thought LA Sleeve used to sell RD400 sleeves years ago?  I could be wrong

[pdxjim]

Wade, y'all can bring them down to superiorsleeve.com here in Portland area to be checked out.

I haven't worked with Charlie Brown (superior sleeve) but he's been at it forever and knows his s#it for sure.

[SUPERTUNE]

It's best to never resleeve.
If getting to max bore, Nikasil plate them.
Sleeving a RD will rob a lot of power. Can be done,if not caring about performance...like the Rajoot RD.
Stay with stock sleeve cylinders.
Chuck

[bitzz]

"Sleeves" are usually press fit into the cylinder bore.
Yamaha, in their infinite wisdom, cast the RD sleeves into the aluminum cylinders. 
You can bore the iron sleeve out of a RD cylinder and press in a replacement sleeve, but it will never cool right, it will have hot spots and cool spots and will never really be concentric.

... I once had a mad dream of a six transfer port RD400....

[teazer]

....... I once had a mad dream of a six transfer port RD400....

And what stopped you?  I have a set of 3G3 6 port TZ350 cylinders and I thing I want to weld on reed boxes and then add boost ports, but I suppose you could order a set of TZ750 OW31 type 6 port plus reed boxes barrels but out of my price range.

At that point, might as well buy a Banshee motor with RZ transmission and fit CPI Cheetah barrels and a +10 crank for a small fortune but t could generate well over 100 rear wheel HP

[85RZwade]

Thanks for the input, I'll see about getting my hands on one for pictures. I believe my friend will want to stick with the stock barrels, as the linered ones sound like a trip to the realm of the experimental.

[paul1478]

At that point, might as well buy a Banshee motor with RZ transmission and fit CPI Cheetah barrels and a +10 crank for a small fortune but t could generate well over 100 rear wheel HP
[/quote]

I hope you are happy. This is all I can think of now...

[85RZwade]

Finally made it over to my man Denny's place today. Got to try out his 2019 CRF250X, went for a spin in the woods on chariots (quads), took a Jeep ride and looked over his various bike projects. Got pictures of the RD400 cylinders at last:









They look nicely done to me. Maybe the professionals will weigh in!

[m in sc]

those dont look to have been resleeved

[SUPERTUNE]

Not re-sleeved.
Looks to be U.S. Daytona F model ported cylinders and the intake track opened up for bigger reed cages.
You should measure the exhaust port height and see if its been raised enough.
CC the heads to see what model they are...or I can tell by pics.

F Daytona model heads will cc @ 23 cc's and C, D and E models are @26 cc's
The headgasket differences with the F model .055 thick one piece gasket and the single copper early models @ .020 will almost make them the same CC.
The issue is the F chamber has horrible head design and develops a high heat burn and is hard to jet out on todays pump fuels.

The U.S. F model carbs were a lean burn setup and makes it worse nowadays.
I like to do 30mm carb conversions for them.

Chuck