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Make sure the valve clearance isn't too tight.

Mark,

Your Kerker pipe with a performance baffle should work fine. We've chatted before about RS34 slide clack. If you're slides are clacking (and your intake ports are burnt) then you are DEFINITELY getting reversion. And this is NOT a carb related problem. The carbs are just letting you know there are other problems in the system. (don't shoot the messenger)

A Kerker or VH WITH performance baffle installed should be fine on the exhaust side.

As long as your valve are sealing (bad stem seals will not cause that kind of discoloration inside the port)and your cam timing checks out then I strongly recommend the following:

Epoxy the floor of your ports. There is NO choke point in those ports. Your choke point should be around 24 to 26mm in diameter. This will do 3 things:

1) reduce or eliminate the reversion/slide clacking
2) provide butt loads of mid range torque that you were after when you built the 1327 motor to begin with.
3) improve drivability and fuel mileage

All without sacrificing top end HP.

My big heavy ST shafty with a 1075, mild performance 0.365 cams and RS34s has LOADS of midrange torque, gets 40+ mpg and turns mid 11's at the track.

I'm running with a 25mm choke point.

davel wrote:

Mark,

Your Kerker pipe with a performance baffle should work fine. We've chatted before about RS34 slide clack. If you're slides are clacking (and your intake ports are burnt) then you are DEFINITELY getting reversion. And this is NOT a carb related problem. The carbs are just letting you know there are other problems in the system. (don't shoot the messenger)

A Kerker or VH WITH performance baffle installed should be fine on the exhaust side.

As long as your valve are sealing (bad stem seals will not cause that kind of discoloration inside the port)and your cam timing checks out then I strongly recommend the following:

Epoxy the floor of your ports. There is NO choke point in those ports. Your choke point should be around 24 to 26mm in diameter. This will do 3 things:

1) reduce or eliminate the reversion/slide clacking
2) provide butt loads of mid range torque that you were after when you built the 1327 motor to begin with.
3) improve drivability and fuel mileage

All without sacrificing top end HP.

My big heavy ST shafty with a 1075, mild performance 0.365 cams and RS34s has LOADS of midrange torque, gets 40+ mpg and turns mid 11's at the track.

I'm running with a 25mm choke point.

Have you been doing your home work? It sounds good to me!!!!

Larry Cavanaugh re-ported, replaced the guides, and valves, and did a valve jod last winter.
The intakes looked like they are still sealing but with the amount of ring blow by i was getting it looks like the exht valves were no longer sealing. I just sent him back the head. He is going to redo the head for me, no charge. He is a great guy.
The new cam chain stretched and the intake cam went from 110LC to 112LC.
as for "Epoxy the floor of your ports. There is NO choke point in those ports. Your choke point should be around 24 to 26mm in diameter. "
I don’t have the experience or equipt to measure my results so I will trust Larry's expertise on this.
How did u verify your work Davel .I recall seeing your epoxy test pieces. Your are miles ahead of me bro.That was some nice work.
I take it u are talking about the exht side only?
I got the bike running well with no clacking from the carbs. But the used 1327 pistons blew smoke bad, so I got Paul Gast to bore a cyl to 1200 for me and supply new J&E pistons so I will be starting completely fresh.
I just what to be sure the intakes don’t get dirtied up again..

Theres a good read in Kevin Camerons"Sportbike Performance" which might help, G

I have been reading that book. what part exactly are u refering to Gane?

was thinking of the section which included cam overlap and exhaust wave interfearance, I think scavanging was the term. most references were to genesis motors and their respective ignition lead times.and exup, still, My main thought is to situations where burning charges can back up into intake tract. I believe chapters 3 & 8 apply. I rec, the book and its entirety, also "performance tuning in thory and practice, 4 strokes by afellow named A Graham Bell. I've seen many engines w/stained intake throats which had excellent leak down #'s still,, a student G

Thanks G. I will go back for a read and refresh my memory.
I think it is just normal reversion . i'm just hung up on the fact that all runners are not getting the same amount.
Larry C sent me this link.

www.maxracesoftware.com/pipemax36xp2.htm

It is a program for finding the correct exhaust length for cars. it leads u to believe that there should be no staining in the intake runners. But from what i understand, the motor will only run at its peek at a small rpm range. This range is very dependant on the amount of overlap in the cams. Out side of this rpm the motor will not breath as well. Such as when a car with big cam overlap idles. it is very rough and almost wants to stall. This is due to the exhaust wave pulse, entering the intakes at the wrong time, and pushing the charge backwards, rather than pulling the intake charge towards the cyl.
i imagine the reversion that makes the RS carbs clack loudly, at lower rpms, is just this. Now as I change the exhaust baffle diameter to eliminate this clacking (which i have), have i just improved the breathing at this rpm and hindered it somewhere else?
So much to learn. I wish i had a Dyno ,But i cant even aford to put mine on 1.

Just my opinion, I would change the intake cam timing or Change the timing of both cams to reduce the valve overlap. A person could try a restricter plate. You change the size hole in the plate to find what you need.........Maybe the easiest fix is to change carb size.

I had my LC at 110 and the intake changed to 112 with the cam stretch. i think i may try 108LC's next.Hopefully the cam has finished stretching.
What were thinking for cam timming?
What is a restictor plate?
why would u think the carbs are the wrong size?
I wellcome sugestions.

mark1122 wrote:

What is a restictor plate?

In NASCAR, it's a flat plate with holes in it that goes between the carburetor and intake manifold. The holes are sized to restrict airflow and effectively reduce the CFM the engine can draw, ie "restricting" the intake.

what would i expect to gain ? at low rpms the carbs slide is the restrictor plate? That's would be where i would get revertion ,wouldnt it?
Nascars run wo throttle mostly.arent there plates used for safety,to reduce speed?