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Post by redbug2 on Aug 9, 2015 5:16:49 GMT -5
Hello,
I've been riding my RE5 a bit more lately. Took it to a show 30 miles away yesterday. I was living with the hesitation between primary and secondary ports but I'm over it and want get it right. Also, its not idling well now. Maybe my main jet is too small? I'll get the number off of the jet today.
It runs well on the primary but when I throttle up it seems starved for fuel during the transition. If I punch the throttle it dies for a second and then it kicks in and the power in fine.
Also backfiring on deceleration.
Any tips welcome.
Regards,
redbug2
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Post by jm0406 on Aug 9, 2015 9:22:32 GMT -5
I think the factory designed them to run that way didn't they?
Jeff
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Post by timpa136 on Aug 9, 2015 11:25:15 GMT -5
Hi redbug,
Some common conditions include an air filter that rotted and some foam pieces are wrapped around the carb. venturis with resulting grit doing no good to the rotor housing.
Backfiring on decal may be contaminants in the carb. particularly the pilot jet causing a lean mixture .
Hesitation you describe may be a soft acceleration pump spring if you have an early type, stretch it to 18mm.
Let us know what you find.
Timpa136
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Post by wayne on Aug 9, 2015 18:26:39 GMT -5
You want the quick and easy bandaid ?
Make sure all your cabling is correct and then fit a 100 main jet. That should improve it if not fix it for all practical purposes. If not, play around with 105's, even 110's. If none of those make a difference, then your carb needs a good going over before you try anything else.
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Post by ohiojoe on Aug 12, 2015 17:00:22 GMT -5
Exactly what one is the main jet?
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Post by wayne on Aug 12, 2015 23:25:50 GMT -5
On the same face of the carby that the air horn bolts to, there is a hexagonal brass bolt head which is also slotted for a screwdriver. Unscrew this. Stick a small flat bladed screwdriver down the hole and unscrew the Primary Main Jet. You might need a long toothpick or satay stick to poke down the hole into the jet to pull it out. The original is probably a 90, possibly an 87.5. You can buy these jets from Show and Go products in Australia if not somewhere in the US. You need a N102/221. Buy a 110 and a 100 to start with to try out and then fine tune later (unless cost is not an issue, buy a whole range in 0.25 increments). Here is the exact page, the jets are about half way down. www.showandgo.com.au/mikuni/mikuni.htm?mikuni_bf.htm~mainFrame |
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Post by redbug2 on Aug 14, 2015 6:40:24 GMT -5
I have a few parts carbs that I picked up on ebay and at swap meets. I took a main jet out of one of them and found a small drill that fit the diameter and then went two sizes up. Wow, what a difference! Great low end zip on the first barrel and very little hesitation (still a little) between primary and secondary opening, but I think I could live with it. No backfire. Better idling.
My brother bought a jet kit somewhere and gave me them minus the one for his RE-5. I'll find it again and test all the sizes. If I get a better running jet (And I may already have it) I'll use it (or drill mine out to same diameter and have a spare).
Also, I do have a new air filter so I'm good there.
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Post by charles on Aug 18, 2015 23:30:13 GMT -5
This one always just leaves me cryin' and it has nothing to do with anyone here... www.google.com/patents/US3347213?dq=walter+froede&hl=en&sa=X&ved=0CFUQ6wEwCDgUahUKEwjU_KqSoLTHAhUKqx4KHZy3C60Note the date on the patent. Click on the picture and look at it awhile. In a peripheral port rotary, the farther the ports are from each other, the less overlap. At low engine speeds in a carbureted rotary tremendous amounts of hydrocarbons get pulled into the exhaust where they register as pollutants. NSU got the KKM-502 engine with a SOLEX carb assembled and NSU attempted to license the PACKAGE as much as they could. Sorta like, "We can put a Chevy 283 in this thing and...". Or, "We can take an AC Ace and drop a small Ford V-8 in this thing and call it a...a...COBRA! That's it!!!". Solex licensed many of their carbs to Mikuni, BTW. So: "If we have a small Port far away from the exhaust, we can get good carburetion on the low end and then we can cable open a big Port that's closer to the exhaust Port as the engine revs and we can get the top end as well. It's complicated but it'll work". You don't have to be a Schroedinger to get the wave mechanics here. At some point, there will be a beat frequency between the 2 ports and a hesitation...and a stumble...and the Solex design was awful to "tune", even in the Ro-80 that almost sank NSU. Yet, that's what we got in the RE-5. NSU later developed the 871 rotary with a Bosch K-Jetronic that was designed for a six cylinder piston engine so in effect they "did it again". The 871 had some nice improvements but until more Direct Injection technology came online, it was a lost cause, like You-Know-what. The Rotary is not a creation from an alien civilization from another planet that is not to be touched. It's a 4 stroke engine that doesn't use reciprocating pistons. Variable Overlap (from Froede in 1965!!!). NO THROTTLE BUTTERFLY! A carburetor somewhat more sophisticated than a soda straw in a cup of water (Notice I didn't say "Complicated"...). Ohhh, where have I seen one of those? Injectors? INJECTORS?!?? There are a few RE-5s that get the proper settings that last for a few miles and the riders sing the praises of the engine all day long. It coulda' been so much simpler. Somebody get me a hanky. I'm getting all weepy again. CW |
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Post by wayne on Aug 19, 2015 0:40:41 GMT -5
It's a 4 stroke engine that doesn't use reciprocating pistons. CW Thank you............please come and explain this to every second dunderhead who states to me "they're a 2 stroke, right ?" There are a few RE-5s that get the proper settings that last for a few miles and the riders sing the praises of the engine all day long. It coulda' been so much simpler. CW True, it coulda' been so much simpler, but getting the proper settings can last more than a few miles, more than a decade. But so does the fear, it never goes away, the nightmares are still there............. is it coming back, when will it return ??Cheers, |
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joe
1st Gear
Posts: 49
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Post by joe on Aug 19, 2015 14:52:13 GMT -5
Your right Charles, Injection is the way to go. When I finally get around to rebuilding my RE5 I'll experiment with Injection. Jenvey and Webber Alpha make suitable throttle bodies, trigger wheels and hardware and GEMS can supply the black box of electronics.
I'm currently rebuilding a rotary Norton race bike which was supposed to be fuel injected back in 1991, Norton Motors never actually got it to run. Now though with time it's a far simpler possibility. The same engine is also used for aircraft and drones and this is injected without any problems so a very good basis for stating my project. I have spoken to GEMS and they are confident they can make it work well. After all, they supply the injection system for the twin aircraft engines and it uses the same parts. Of course, an engine used on the road is far different to an aircraft engine which probably just maintains a constant RPM.
Also, Van Veen made one fuel injected bike and prepared another ready for the system with the twin fuel return in the fuel tank. This was a mechanical Pierburg fuel injection system which gave a 30% increase in power, increasing the OCR 1000 to 130 BHP. Not bad for a bike in 1976. I believe this was the same injection from early Audi's. The fuel injected Van Even was delivered to an Arab living in England and all black including all screws and fixings. After a few years of use it gave trouble and was taken to a rotary expert in England which removed the system and transformed it to carburettors. Recently the new Van Veen company in the Netherlands acquired this bike and bought the spare complete injection system from a friend and have now returned the black bike back to it's original format. When I visited them last year they were still rebuilding the bike so I don't know if they got it to run but I plan to call in in a few weeks when I attend a rotary show not far from their works.
Regards, Joe.
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Post by charles on Aug 19, 2015 16:22:35 GMT -5
Wonderful!
I'll try Posting more on this tonight but the situation as stands now on the intake side is:
1. We can get any size opening with Variable Overlap and no Throttle Butterflies or ANYTHING in the way of the airstream into the engine. BTW, the Direct Injection work from Curtiss-Wright on was unthrottled but was designed, esp. at the end of that time period, for high RPM work. This was continued when John Deere bought the rights to the engine from Curtiss-Wright. We get all of this for our lovely Sunday outings right out of the box. DI may eliminate the need for Variable Overlap but the ability to have any size Intake Opening still is an advantage.
2. Mazda won Le Mans with the 4 Rotor which had a different type of Variable Intake. The Intake tubes, like a trombone, could be extended for lower speed torque advantages and shortened for high RPM work. Brian Crighton's CR-700 P motorcycle (through decades of work on the Norton Series) has the same thing. A virtual Constant Torque (high) value at any RPM. No more peakiness in a high output motor.
3. Curtiss-Wright split the Direct Injection machinery into 2 parts: A "Pilot Injector", located a little after ATDC. This pocket contained an injector and spark plug combination and used a very small fixed amount of fuel for ignition and a "Main Injector", located BTDC, which would supply fuel at any amount.
4. Mazda has determined the better/best size for the Pilot Cavity and a very good place for the Main Injector. There is work that has been done on a Norton with Turbocharging (!!!), using the Heavy Diesel fuels (!!!) that used a well designed Pilot Injector and a Glow Plug (!!!).
That's just the Intake stuff. References and other stuff later. You can take out a sheet of paper and a pencil and write all of this that could be done to the RE-5 from the simplest, with little or no machining, to the entire top end. MOST OF THIS MACHINERY IS ALREADY IN EXISTENCE, as Joe has implied. All it would take would be money, earplugs and a laptop (Hopefully running Linux...) for the Mapping of the Injectors and control of the DC motors for the Intake Tube. And some cabling. We're used to dealing with cables with the carburetor we already have...
Advantages:
A. No more 3000 RPM hesitation.
B. Hold on and find out something about Rotary engines.
More later, hopefully tonight.
CW
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Post by allen on Aug 24, 2015 3:50:23 GMT -5
On the same face of the carby that the air horn bolts to, there is a hexagonal brass bolt head which is also slotted for a screwdriver. Unscrew this. Stick a small flat bladed screwdriver down the hole and unscrew the Primary Main Jet. You might need a long toothpick or satay stick to poke down the hole into the jet to pull it out. The original is probably a 90, possibly an 87.5. You can buy these jets from Show and Go products in Australia if not somewhere in the US. You need a N102/221. Buy a 110 and a 100 to start with to try out and then fine tune later (unless cost is not an issue, buy a whole range in 0.25 increments). Here is the exact page, the jets are about half way down. www.showandgo.com.au/mikuni/mikuni.htm?mikuni_bf.htm~mainFrame |
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Post by allen on Aug 24, 2015 3:53:19 GMT -5
Wayne is there a carb needle and seat available from mukini, I have located the jets N102-221 type you quote, if needle and seat is available can you quote the number?
Regards allen
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Post by redbug2 on Aug 24, 2015 19:57:16 GMT -5
RE-5 is now hard starting and not idling as it used to. Running great under a load but it seems labored at idle and stalls often. Smoking more than usual on startup after sitting, but, eventually cleans itself up.
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Post by wayne on Aug 24, 2015 20:42:26 GMT -5
Wayne is there a carb needle and seat available from mukini, I have located the jets N102-221 type you quote, if needle and seat is available can you quote the number? Regards allen Allen, unfortunately that's something I haven't investigated as yet. Perhaps someone else has sourced them, they were available in the carby rebuild kits but they've pretty much disappeared. |
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