Topic: Result from Dyno run: Too rich at 4500-6500 rpm 4-2-1 exhaust better than 4-1?

[Retro Rocket]

you might have to change out the needles to a leaner needle or a leaner needle jet
on all of my double over head bikes with the various cams that I run, I have found the a 105 In and a 107Ex '
is the sweet spot on all of my bikes
but with a single cam your stuck but the 105/112 numbers might get you in the ball park
I would really take a look at your needles and check your ignition (What type of ignition)
good luck
Jim

The guy that ran my bike on dyno had full throttle, needles not involved. When increasing throttle slowly up to full, no problems at these rpms or needle area throttle lift.
I'm searching for a good 4-2-1. CycleX has one that look good.
http://www.ebay.com/itm/Cycle-X-Honda-CB750-4-2-1-Race-Exhaust-Chrome-Header-Only-Chopper-Bobber-Cafe-/151526109837

I found another 4-2-1 http://www.ripplerockracers.com/product/cb750-hindle-vintage-racing-exhaust-system-fits-1969-78/

Which design is better for a CB750 SOHC? CycleX design of 1-4 + 2-3 seems to be more common when searching on 4-2-1 headers. 1-2 + 2-3 might not work as well as  1-4 + 2-3?
Firing order 1,2,4,3 and need of not getting exhaust gases backwards into a cylinder from another cylinder earlier in the firing order.. (this might be the case here when the cam exhaust has very early opening, 76 degrees BBDC wich is around 20 degrees earlier than most other cams.

Improved midrange fits my engine well when the max power at red line is not that important with weak rods. I had planned 4-4 pipes, I think I have to find another bike for them

I have to test other cam on dyno with existing 4-1 and new 4-2-1. Later on install the megacycle 125-20 cam again and see how a 4-2-1 and measure the interaction of them both.
The Megacycle 125-20 cam might need higher CR? I have longer rods (CB900 DOHC) that can fix that in next engine build.

Pewe, schuele {German} make on of the best pipes if not the best, for the 750, its a 4 into 2 into 1 , motoGPwerks also does a very good 4 into 2 into 1

http://www.schuele-maschinenbau.de/pages/ausp_klassik/cb750_rick.htm

Motogpwerks, Chris only makes these in small batches

http://www.ebay.com/itm/HONDA-CB750-K0-K7-F1F2-EXHAUST-STAINLESS-4-2-1-RACE-YOSHI-TYPE-CAFE-RACER-SOHC-/121365841174?pt=Motorcycles_Parts_Accessories&hash=item1c41f7c516&nma=true&si=8L2P6qZJ9O2%252FIhyn8rQe9SjAN9A%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

[PeWe]

You re-jetted the carbs AND swapped the cam? Best to make one change at a time, lest you start chasing your tail.

I had planned to check that cam on the dyno anyway.
Cam off to fix an old bad cam stud helicoil that raised from the head taking the aluminum on its way up.
I guess that carbs will work for both cams when properly jetted for correct A/F ratio. Filter/stacks and exhaust changes make more for jetting, right?
I'll see what the dyno will show for the AF and power. Chart to be posted here or the dyno/cam thread.

I have a CycleX CX-7 cam too, not tested on dyno, yet 

Retro Rocket: Thanks for the exhaust links.
Motogpworks look nice and functional.  Over $300US will be added for shipping and customs+Vat
I guess the original rear foot pegs will be possible without rasing them with a bracket. Other systems are often too much bent upwards that interfere with a passenger.

[scottly]

Your jetting was spot-on at 8000-8500 RPM, the beginning of that cam's "happy place".  If the next test with the milder cam shows lean, you know what to do...

[PeWe]

Your jetting was spot-on at 8000-8500 RPM, the beginning of that cam's "happy place".  If the next test with the milder cam shows lean, you know what to do...

Yes, needles up one step if the lean happen where it before was way too rich.  Plugs are a little bit lighter now, oil temp in tank was 100°C after last test drive.
Mains 132.5 should not change for the milder cam...? A/F will show where lean or rich.
I need to test more, the old milder cam felt very boring after the other much happier cam.
Confirm carbs again with my CX-7 cam Then I know the power of my cams. (except OEM cam)

[PeWe]

Tested the milder cam yesterday with needles 2 steps lower. Still a rich dip. I have not got the dyno charts on a file yet.
It made 80whp with the mild boring cam    I'll publish the chart when I get it (tomorrow)
Action Fours have this in the catalogue: Action Fours SS-1. For those riders that are worried about “hot" cams

I stood beside and made a video.

I guess I have to find out how to adjust the acc pump.

[Old Scrambler]

Nice Work.............and appreciated

Looking forward to my dyno session on the CBR............should be in a week to 10-days.

[Retro Rocket]

That sounds very sweet Pewe...

[brandEn]

Sounds GREAT!

[PeWe]

Latest Dyno run with the old milder cam (Action Fours SS-1. For those riders that are worried about “hot" cams)
See attached pdf
I attached both dyno runs as png as well.  The carbs are not that rich now. The acc pump might be next to adjust. I changed neddles 2 steps leaner from first run. Now clip in 2:nd notch from top.

It's different to watch from beside when engine is screeming past 8000 - 9000 rpms :-) std rods

Not much less power with the milder cam.
I had fine tuned the points (same dwell angles, before only feeler gauges) and ignition the day before.

[johno]

Hi PeWe,
Love the video,
The rings are well bed in now 
chers Johno

[PeWe]

The video is longer, but the noice from the ventilation fans drowned the really nice sound at idle before the real test started. Even the guys working at the tuner Motospeed (wellknown tuner in Sweden since 35-40 years) liked the sound.
Several other guys (with bikes to the dyno) were impressed. 100-150 and even more whp is very common for those guys and they asked what bike is that???

It's very tempting to reinforce the engine and try other cams. Like old RC cams now DP something....

[Jerry Rxman Griffin aka MuthaF'er]

Looks MUCH better. May need to enrichen the needle one notch.

[PeWe]

The details has started to reveal themselves. I adjusted the points last week encouraged by Mike Riecks thread about his point adjustment with a dwell meter, 8cyl setting. http://forums.sohc4.net/index.php/topic,147444.0.html
I got both points equal about 23.4°. Idle much better. I'll try to close the mixer screws when it felt a little bit rich on very low throttle lift. 1 turn out now, will try 3/4 and see.
I have a smooth non sticking clutch now, much easier to start.

Needles are really easy to adjust, no need of lifting the throttles, lift the tank plus the top covers on carbs.

[PeWe]

Looks MUCH better. May need to enrichen the needle one notch.

Yes, did the needles today, (3:rd notch of 6 from top). 1 step richer that made engine to run better when twisting the throttles very slowly from idle. Before too lean. Twisting very quick had really good responce when the pump did the fuel delivery.
Fuel screws to the richer did not help. Needles did.
Fuel screws now 1 1/2 turn out.

[PeWe]

Time for an update
I have changed cam again, now an  "RC295 copy". @ 0.04" lift:  25/55  55.5/22    lift: 0.393" / 0.363"
Better power than my old AF SS-1.
It seems to be easier to jet the TMR32 carbs with a less overlap cam (compared with 125-20, CX-7).

I'm using the free Road Dyno....
Now jetted richer
-Larger pilots. Back to the initial 27.5 as the carbs had at delivery
-Fuel screws 1 1/2 turn out.  1 turn only gave lean low lift and hesitating engine when cruising in low speed. 1 3/4 too much.
-Needles 4:th notch as at delivery of the carbs.
-Main jets up too. Now 135, better response around 160kmh. I think I can use 137.5 and hopefully get better response after 180kmh..passing 200kmh.....
No problem with acc pumps when giving full throttle yet. 
It will soon run better than ever before!

Back in the days it accelerated to 200kmh rather quick, sloooow to 210kmh. Now + 50% more of me hopefully compensated by better carbs, cam....

EDIT: 137.5 too large.. plugs darker than before...back to 132.5 that is verified on Dyno and slightly lean side of perfect line. 1 step larger Pilots and richer needles since then though.

[scottly]

Free road, AKA butt-dyno, doesn't count. Seriously, it is too bad you couldn't get a proper dyno test with each cam...

[PeWe]

Free road, AKA butt-dyno, doesn't count. Seriously, it is too bad you couldn't get a proper dyno test with each cam...

Yes, it would have been nice to have the first cam Megacycle 125-20 perfectly running and not way too rich with full throttle as I got.  It began with 1 bad spark plug wire with intermittent function that tricked me to jet pilot too lean when it smelled rich at idle due to intermittent plug 1.

Cam might have been too advanced. I had too much thoughts about good idle closing inlet valve not late. That cam has a very early opening of the ex valves. 73 BBDC according to the card, 76 in my engine @0.04" lift.
It might be different if I should have timing it at least 3 degrees later or more like EX opening 70 degrees BBDC.
I installed cam: 30.5/58.5  76/22  LC: 104/117
? Better?: 24.5/64.5  70/28         LC: 110/111 

Maybe 1000cc and later timing will do a better combination?

[MRieck]

Time for an update
I have changed cam again, now an  "RC295 copy". @ 0.04" lift:  25/55  55.5/22    lift: 0.393" / 0.363"
Better power than my old AF SS-1.
It seems to be easier to jet the TMR32 carbs with a less overlap cam (compared with 125-20, CX-7).

I'm using the free Road Dyno....
Now jetted richer
-Larger pilots. Back to the initial 27.5 as the carbs had at delivery
-Fuel screws 1 1/2 turn out.  1 turn only gave lean low lift and hesitating engine when cruising in low speed. 1 3/4 too much.
-Needles 4:th notch as at delivery of the carbs.
-Main jets up too. Now 135, better response around 160kmh. I think I can use 137.5 and hopefully get better response after 180kmh..passing 200kmh.....
No problem with acc pumps when giving full throttle yet. 
It will soon run better than ever before!

Back in the days it accelerated to 200kmh rather quick, sloooow to 210kmh. Now + 50% more of me hopefully compensated by better carbs, cam....

Geez PeWe....those cam #'s are real close to the 125-75

[PeWe]

Geez PeWe....those cam #'s are real close to the 125-75

I thought so too. I had 125-75 data in my mind when timing. When I got IN 25/55 I was pleased, just checked EX just for sure.
"RC295 copy". @ 0.04" lift:   25/55      55.5/22    lift: 0.393" / 0.363" (9,98mm / 9,22mm)
125-75 cam spec  @ 0.04" lift: 26/56  53/24      lift: 0.400" / 0.375"  (10,16mm / 9,525mm) 
Real cam with rocker arm lash will get slightly less ?

I cannot see my cam as a sudden 7000 screamer either. It pulls even from low, better after 6000. Very comfortable on 5:th gear when cruising around. OK from 50mph to just twist without any complaints or hesitation.

Mike, I understand why you like a cam with this data   Mine is marked RC295 but is closer 125-75 as I have found out so far.

My bike need a new gadget.
Air fuel gauge so I can check the jetting when and how I want.
At idle, the few mm lift after idle and while cruising up to higher speed as well as WOT.
Todays road test with larger main jets did not increase power or response. I need to step back to 135. It would be nice to see the AF ratio.

A gauge must have logging so the result can be checked afterwards as well as see the gauge when possible. Difficult to check a gauge at high speed driving.
Wego 3 fulfills my need but cost some. Cheaper has probably no logging system with rpm reference from an ign coil as this one.
http://www.daytona-sensors.com/WEGO3.html

I have not found a good looking sniffer to be mounted at rear of my exhaust during road tests.
-I have to weld it into the exhaust right? Hole in exhaust, weld a threaded insert that can be plugged when sensor will be moved to another system....

[PeWe]

Update if other will use TMR32 and similar setup as I have.
Cam still the last one installed a month ago. I really like it!
Carbs are now OK for street use. Good idle, smooth operation from idle to WOT. Jets cannot be better! No too rich at WOT as I had before with the Megacycle 125-20 cam. Overlap and exhaust cam data did that ?

Pilot jets increased to 30  (std pilot 27.5) 
Needles still at 4:6 notch. (std setting)  3:6 caused pinging with the other jets.
Main jet 135 (std 150)   (137.5 did not improve, 132.5 less response and torque on 5:th gear from 80kmh and up)

Fuel screws  1 1/2 +1/8 turn out.  (only 1 1/2 hesitations at low lift)

Next is the exhaust system. I think my 4-1 is restrictive and cause some power surge from higher speeds 160-180kmh.
I'll try a Yoshimura replica with bigger pipe diameter from where the 4 pipes goes into 1.
Update to come later when tested.

Next dyno with better rods. I do not want to press my luck...

[Garage_guy_chris]

I can maybe add a little info on that Ripple Rock Racers Hindle 4-2-1.  I ran into Kemp, the guy in charge of these systems at our local bikes and coffee here in Toronto. He had the cb650 hybrid bike on the ripple rock site there and I started asking questions. Turns out he has been working in conjunction with Hindle to develop this line of systems and the exhausts are all dyno tuned and proven. He is a very knowledgeable well known guy in the Toronto scene. Also note the ripple rock site is in CANADIAN DOLLARS so with any US members it would put the system at about $530 USD

I have been wanting a new exhaust system for my build rather than deal with the old beat up systems I have. Kemp gave me a good deal on a system and being in Canadian dollars with the US exchange being what it is put it way cheaper than any other options. I couldn't resist so i picked one up

I havent got it on the bike yet but Im maybe 2 weeks out for completion and tuning so i should have some more input after that.

[Old Scrambler]

Looks like it will have to removed to change the oil-filter ..............but otherwise looks good............What is the pipe ID at the head and at the 2 into 1?  Also, when they say dyno-tuned, what size motor?

[bwaller]

Lang Hindle knows his biz. I'll bet it's a good pipe. Mike Rieck has an earlier version.

[kmb69]

Looks like it will have to removed to change the oil-filter ..............

Spring mounted so comes off real easy.
Does look very nice and a really good price for stainless IMO.

[PeWe]

It look really nice and slim fit!
I thought that a 4-2-1 should have 1-4,  2-3 to the collector for best performance.
1-2, 3-4 is Ok too or even better on a CB750?