Reed ID

[SmokeAddicted]

Chasing an air leak, and I've not pulled the reeds until now. Turns out cheap spacers can be a problem.

Material has been removed from the cylinders. Spacers are approx .33 inches. Any ideas?

[1976RD400C]

I checked some oem 350/400 reeds and they are the dimensions you have there. They should fit in the cylinder without having to remove any material or needing a spacer.

[IR8D8R]

You really need gaskets on both sides of the reed block. The rubber manifold doesn't reliably seal the connection.

IR8D8R

[m in sc]

^ agreed.

[SmokeAddicted]

I tried, but they do not fit without spacers. Intake port was hogged out a bit, prior to my purchase. I can only assume that's relevant to these reeds being installed.

Ran into Tony Doukas at Barber, and he confirmed it was his design, but I didn't think to ask from which platform. I guess he private labeled for other vendors throughout his career.

42HP on the dyno. Seems like a reasonable number. I haven't had a need to pull the top end, so I don't know what I have.

[1976RD400C]

Here are some reed dimensions.

[m in sc]

those cages look like some early DT125 units, that offset hole.

i think you're giving up power with those chambers.  a stock bike can put down 39.

as far as reeds go, those will be 'ok' but you can get RM100 v force reeds to drop straight in w no spacer needed. this will help, removing the spacer on your setup 

[SmokeAddicted]

Interesting, Mark. What makes you say I'm giving up power with the chambers? From what I can tell, they are Spec 2 RD400 chambers.

We dyno'd Greg's bike with those Indonesian pipes and he was making 35hp

[m in sc]

not a 400 motor. the headpipes lengths are a bit different.

I put down just under 32 rwhp on my 72 R5 with the r5 cyls, stock heads, no porting and pipelyne chambers. (rob hall dynoed it back right before i swapped the cyls to rd). I would think an rd would put down a bit more. however w the unknown top end condition, who knows. last rd i dynoed YEARS ago put down 51 rwhp with specII f1s and pwks and an a static cdi. 

not disparaging or talking shit, just thinking you should be closer to 46-48. 

[SmokeAddicted]

I definitely do not take it as talking shit, etc. I'm eager to learn, so any and all information when it comes to performance (or RDs in general) is 100% welcome. There's a lot of bullshit out there. I can take your word as RD gospel, so I appreciate the feedback.

I've been researching pipes, and I may have a line on some old Moto Carerra race pipes, but I'm sure porting would be in order if I decided to purchase them. 

[Kawtriplefreak]

I am running Moto-Carrera chambers on my stock ported RD350B with TM32s and Vintage Smoke ignition and it runs really strong. Never had it dynoed but you don't need to port the motor to run them.

[SmokeAddicted]

Thanks, Kawi. How's the low-mid range? I have nice throttle response at roughly 3K RPM. Power comes around 6500.

[Kawtriplefreak]

https://youtu.be/Efckn50aqiA?is=FamudEpqvy37Mw1h