I just did my test on the Dino. Not very conclusive unfortunately. Removed # 5 and car started as usual. Revved to 3k a bit lumpy Above 3k seems fine even with # 5 disconnected. Shut it down and removed both 5 & 6 at the same time and car would not start !! Shut it down and reconnected 6 leaving 5 off and car started. Then disconnected 6 too with car already running. So, now both 5 & 6 disconnected and car running. Rev up to 3,000 is about the same (lumpy). Above 3,000 seems ok with TWO leads off. Reconnected all leads and car starts fine. Under 3k a bit lumpy. Above 3k seems ok. I was really expecting to have noticeably bad running with TWO leads disconnected. But not as noticeable as I hoped. Only noticeable item was that the car would not START at all with both 5&6 disconnected. Once the car was started and running, I could remove both 5 &6 without really noticing much of anything. I will say that this is just revving in neutral without the engine “under load”
Image Unavailable, Please Login I would take out the idle jets and blow them out and clean with a really thin wire. These get clogged occasionally from gas varnishing. Might be the culprit! Note: Photo from Rob and Paul Calisi.
That fact that you have a V4 instead of a V6 and didn't noticed much above 3000 proves my point, you wont with all that noise. If you have to rev the car excessively and basically slip the clutch to get going then you have a problem in the idle circuit, pumping the throttle is just dumping excess fuel down the throats from the accelerator pump circuit. Badly set up idle via the linkages can be the problem especially if you have one throttle plate (or two) open to far, this tends to keep the car running but the others are lean and starved. go back to basics on the settings disconnect all linkages & wind out the idle screw, close the air bypass screws and carefully close the mixture screws and stop as they bottom out.. This is how I do it, some may do it differently but we all get to the same point with a smooth running engine. clean out all idle jets Check all jets, emulsion tubes and main jets etc are as spec Check float levels, worth doing as it can cause flooding issues Check accelerator pump circuit is working (check diaphragms are Ok, most go rock hard and don't work) Make sure accelerator pump is NOT activated at idle (fuel dripping onto the throttle plates) Pre checks open the airbypass screws 1/2 turn out and lock off with the backnut Open the air mixture screws 2 full turns slacken off the heim joints so they are loose . Wind the idle screw 1.5 turns in and reconnect all the carbs linkages making sure they don't alter the pre commission setting, leave slightly loose as they WILL need adjustment and fine tuning Start car and don't worry if it runs lumpy, get someone to keep the car running on the linkages while you start the car. Check airflow through all six chokes and balance out with the air bypass screws. Don't open to much otherwise you will lean out that barrel and get a unresponsive idle mixture screw and snapping / popping out of the exhaust. Adjust the idle screws slightly to achieve equal running on all 6 chokes. If you get a smoky exhaust at idle then you need to fiddle around with the air bypass screws Wind in the idle mixture screws slowly until you hear a noticeable drop in revs, then wind back out until the revs pick up a max. You may then need to readjust the idle speed. Work on one barrel / carb at a time ie carb 1 then 2 then 3 Reconnect the linkages and tighten up the nuts to each heim joint with the car running, any change in revs then you need to adjust the linkage to bring it back in line. Check airflow hasn't changed. Its not an easy task to master setting three carbs, I spent many hours fiddling with mine over the years and can set them up quite easily now. Persistence and a appetite to learn to do it yourself is the goal.
Thanks Freeman. Great photo ! Tony I really appreciate your taking the time to outline the process for me. You’re spot on as far as having to slip the clutch to get things going and also the V4 / noise commentary! Once I get things sorted I may go with the BSM electronics though Superformance as you discussed in other threads....life is short. I’ll tackle things with my mechanic after vacation. Thanks again for your effort ! Headed to your territory of Bermuda soon.
Hope it helps, there are a lot of books about and online to assist you. Learn how the carb works and you should be able figure out whats going on. The basics are really simple, the hard bit is getting all six to talk to each other!! The Black Stallion module is no longer made and Superformance stopped selling it some time ago, it was a good piece of kit but had a fundamental floor in that it chewed up coils through overheating. I ditched it in the end because it started to misfire and went back to a basic Superformance super 4 ignition in a original MM box and points. I had the original dizzy proffesionally set up on a machine and it works great.
Thanks for the info on the BSM. They still show it at Superformance but on backorder...... I guess I'll stay original. I'll update the results when sorted. Skipp
Here are links to a few articles I wrote a few years back on the subject: Carb tuning #1: Weber DCNF carbs and their adjustments explained: http://dino246blog.blogspot.com/2014/08/carb-tuning-1-weber-dcnf-carbs-and.html Carb Tuning #2: Tools needed, pre-tuning prep, & general pre-requisites: http://dino246blog.blogspot.com/2014/08/carb-tuning-2-tools-needed-pre-tuning.html Carb Tuning #3: Setting idle, synching carbs, & air correction: http://dino246blog.blogspot.com/2014/08/carb-tuning-3-setting-idle-synching.html Carb Tuning #4: Setting the idle mixture & understanding the low speed circuit: http://dino246blog.blogspot.com/2014/09/carb-tuning-4-setting-idle-mixture.html Carb tuning #5: The High Speed Circuit (HSC) Explained: http://dino246blog.blogspot.com/2014/09/carb-tuning-5-high-speed-circuit-hsc.html Carb Tuning #6: Modern Fuels & Jet Selection When Tuning: http://dino246blog.blogspot.com/2014/09/carb-tuning-6-modern-fuels-jet.html
I know it is a lot of work but I would clean and rebuild all the carbs. Pull and examine the distributor for wear and lubrication and make sure all your valves are adjusted properly. Then you would know all of the top of the engine work is spot on. I think you mentioned the car didn't get much use for 15 years.
Skipp, For the standard points ignition, you can’t do better than the Winterburn CD ignition. It’s a direct replacement for the Dinoplex. I use the Flame-Thrower #40511 as per Fred Winterburn’s suggestion. This coil can also be used direct as the emergency coil w/o the CD ignition. Freeman
Thanks again guys. I’m going get the carbs rebuilt, service the distrutor & Winterborn box. Nothing like being thorough. Appreciate all the suggestions. It’s great having commrads supporting the Dino cause. I’ll update on the process.
Freeman what spark plug gap are you using with the Winterburn & Flamerhrower ? I have mine at .025 “ Thanks Skipp
This is from an old email from John Corbani: “I run NGK BPR7EIX Iridium plugs gapped to 0.03"-0.04". Have over 5,000 miles on latest set and they look great. Was never able to get much over 2,500 miles on conventional plugs before hard starting became a problem. I changed out a set of NGK Platimun after 15,000 miles and they were still fine, although obsolete. I run standard points with aftermarket replacement for the Dinoplex. Try the NGK Iridium, you will like them.”
Itks best to go through the carbs, but... I have a 44DCNF on a bike. Three or four times over the years it has started poorly after a couple years of non-use. I have never opened the carb yet and it’s an ‘88. Each time, a small dose of Sea Foam in the fuel tank would clear out the clogged circuits, within two or three days of daily starts and working through the different circuits with the throttle. Even when it was bad enough the first time, to clog the fuel filter with green sludge. So, there’s a chance it will clear out with carb cleaner added to the fuel. If you care to try it first. I would not pour it in the intake or a vacuum line, as some people show to do. I only use it by adding in the tank with the fuel at suggested rates or less. I have other vehicles and equipment that sit long term that it has helped in this way as well.
Thanks for the suggestion, I’ve run Techron in the fuel last year. Going to do a thorough rebuild and set up of the carbs sometime soon.
I want to thank you guys for giving me the information and courage to tackle the carb adjustments for the 1st time. After confirming “spark”, I purchased a synchrometer and started the process. Fortunately, the air flows were all identicle so I moved on to idle adjustments and mixture screws. I spent the entire day on this, learning first hand what the effects of various changes are. After setting the idle to 900, I started with the mixture screws. At approx 2.5 turns out from fully closed I found the optimal running. Much more “out” from that point, I would get backfiring when revving,etc. when opening the mixture screws excessively, ie 5 turns out, the idle would get very lumpy, but never stalled out. At 2.5 turns out, the idle was good and backfires were gone. I had to re-adjust the idle again after setting the mixture screws at 2.5. If I turned the screws further inward from 2.5, the cylinder would starve at about 1.5 turns out from fully closed. I haven’t driven the car yet, but I think I’ve got things running properly. Skipp
Well done, its the only way to learn, roll your sleeves up and have a go, remember small adjustments when turning the idle mixture screws and wait a few seconds for the car to respond. You will get to learn how your car behaves and feels, sounds like you are in the right area at 2 Airflow adjustments is more frustrating so you have that to look forward to what airflow did you get, about 4 is OK, no higher otherwise the throttle plates are too far open.
Thanks Tony. The airflow was at 3.5 to 4 when I started. Raising the idle sent the air flow higher. Also setting the mixture too rich had the air flow up to around 9 to 10. In the end, I set the final idle around 1k so they ended up being a bit higher than 4 and all even. Will report back after my next drive.
3.5 to 4kg/hr should be OK, max 4.5 on my car. remember the higher the idle you settle on the more chance you have in bringing in the 1st progression hole. If the mixture screws respond then you should be OK, an un-responsive mixture screw can be blocked idle jets (including the passages in the carb, not just the jet itself) and a idle speed that is to high. settle for about 900rpm
I also blew out and cleaned the idle jets and performed a compression test prior to the carb adjustments. All checked out. Thanks again for your insight.
