C.D.I. conversion for the Mac engine

[gyromike]

Tuesday I installed a CDI conversion on my Mac engine. This is Rick Whittridge's magneto conversion. I bought it from one of our chapter members who decided not to use it.

The installation was straightforward, and everything went according to the directions. I had also spoken to Rick on the phone, and he was very helpful.

All of the internals in the mag housing are finely machined, and the CDI is potted to protect against vibration.

I mounted the coils on the top of my upper engine mount, taking care to leave clearance between the prerotator cable and the pushrod tubes. The CDI unit mounts between the mag housing and the upper engine mount. And the mag housing goes...well it goes where the old mag went. :)

I am using Champion D-9 (509) plugs from the local carquest @ $2.24 a piece vs. $15 a plug for reconditioned fine wire aircraft plugs, and stainless core 7mm ignition wires with 90º boots on the plugs and straight boots into the coils. The plugs are gapped @ .030".

Timing was a snap using Rick's instructions too. I set it to 21º BTDC.

After wiring the switch, and tidying up the wires, we rolled it out side and it fired on the 3rd pull of the prop. No stumbling, no spitting, it just started. Several times.

Yesterday, I took it up for a late afternoon flight and it ran like a top. Same thing for today. The highest CHT that I saw with the retarded timing is right at 400º on climbout, and that drops quickly on power reduction.

The idle is smoother and I was able to reduce the idle speed a little, but since my TinyTach bit the dust I'm not sure of the RPM's.

I'll attach a couple of pictures of the installation.

[gyromike]

CDI picture 1.

[gyromike]

CDI picture 2.

[Rick Whittridge]

Hey Mike , Your installation looks good. Pretty straight forward to install.Glad to see another MAC up & running with my system. I hope you enjoy the mag as much as I do. It`s nice to know you don`t have to worry about when the old point mag might give you a MAC ATTACK! Enjoy & feel free to call anytime for your Mac needs. I `m dedicated to keeping the Mac ALIVE!

[gyromike]

It gets a big thumbs up from me, Rick.

It hasn't taken more than four pulls on the blade to start it, usually just three.

And when it fires...it's running!

[StanFoster]

Mike: Nice setup. I wish I had that on my Mac years ago. It was a rush flying that thing. Times I never will forget..especially the attacks.

[joeheli]

Nice gyro can we have a picture of the gyro? :D
what kind of paint did you use to paint your Mac? :confused:
I am planning to paint mine.

[gyromike]

Stan,

I've never had a Mac Attack (siezure) yet, although my Mag had given me some trouble, and I had a little carb trouble occasionally (trash). Mainly the magneto though. I did break a ring once, but it still flew. I just had low compression on one cylinder.

I run it a little rich, and use Amsoil synthetic 2-stroke oil.
8 oz. Amsoil to 5 gallons of AvGas.

-------------------------------------------------------------------------

Jose,

go to the Instrument Pod thread that John Stevens started:
http://www.rotaryforum.com/forum/showthread.php?t=631&page=1 , and my gyro is the first picture that John posted.

I used high temperature engine paint on my engine case:
Dupli-Color Engine Enamel
Daytona Yellow - DE1642
http://www.duplicolor.com/products/engine.html

[joeheli]

Thank you Mike! :cool:

[joeheli]

Did you took out the cilinders to paint? what is the all prosidure of painting?
is my first time painting a engine. :confused: Did you pain your gyro with the same paint?

[gyromike]

Jose,

I disassembled the engine and rebuilt it myself, so I painted the engine case seperate from everything else.

I think I used black exhaust header paint on the cylinders, and then baked them to cure the paint. I can't remember right now.

My instrument pod is painted with Yellow paint, but I don't remember the brand. Maybe Krylon. I just used whatever was closest in color but it is not an exact match with the rest of the frame.

The frame is powdercoated yellow, and the cheek plates, cluster plates, angles, etc., are powdercoated Gloss Black.

The instrument panel is powdercoated in black crinkle-coat.

I had the powdercoating done locally for about $500.

[joeheli]

Ok,Thank you mike.

[gyromike]

Jose,

I plan to have it at Bensen Days, if you want to get a closeup look at it.

[joeheli]

I will be there Friday,Saturday and Sunday see you there!

[Sonnyj]

Rick Please send me Info on your CDI system.Do I need a battry and a gen.

[joeheli]

Sonnyj, I have the CDI . You don't need no battery or a generator.

[Sonnyj]

Ola Jose Do you mean you have one for sale,if so how much.

[joeheli]

Hola! No, I don't have one for sale. I have mine on my Mac . Belive me is worth to buy it.

[DanR]

Amen!!!!! if you aint got one get it!!! its every bit as good as everyone sezs!!

I am fairly new on this forum, the infomation you get here is priceless!! Example is Rick replyed to my post on cowls showing a picture of his engine without the cowls, so I took mine off it has already saved me a lot of time inspecting the engine, but the kicker is while looking at the engine I could see the piston pin with the hollow end was visible through the exhaust port. I remembered in the Bensen manuel it needed to be turned opposite when you turned the cylinders exhaust ports up, I had presumed it was right when I bought the engine. There is a lesson in that somewhere, anyway got it all back together and it runs perfect it even IDLES! but without this forum I could have had a ruined engine or worse. Thanks everyone!!!!!!

[Sonnyj]

Hey Dan I must have missed that thread.I'd like too know,do they go up or down?Also I'm told my 72HP Mac.never had Cowls,I was about to start making them.If I do'nt needem,that's great :D

[Rick Whittridge]

Frank, check your private messages for your info!
Thank`s Rick

[Caribean_gyro]

depending on where you live you make the decition of using cowls. here in the caribean at 90F you need to cool the engine. from CDI,good oil,cowls and even ionizing fuel. The trick is to have the MC running cool and confortable. He will last a life time.
chuckp

[joeheli]

Sonnyj,This is my engine with the cowlings. I think is better to use it if you live on a hot weather or a cooler one . This mac are verry hot engine, so the cooler the better. The only thing I have try is ionizing fuel. Caribbean gyro use them on his fuel and says that is worth it. Peterson please tell me the place to get them.

[joeheli]

This is Rick CDI.

[joeheli]

There is the system on Gyromike engine.I hope Mike will not get upset.

[gyromike]

There is the system on Gyromike engine.I hope Mike will not get upset.

No problemo, amigo. :)
Post away.

[Chuck Irby]

Jose, your paint job looks real good. Now when are you planning to move the rock guard back?

[joeheli]

Chuck long time I don't here from you!!. This picture is about 1 month old. I already took it out and made some magerment to make the new holes.

[Sonnyj]

Hola me amigo coma esta tu
Thank you so much for the pics.Man what a paint job!That is beautiful Jose.Rick is sending me the info on the CDI system yours looks very nice.I found a place here that odered a kit for my Holly and Monday I'm gonna order a new fuel pump,I can't find parts for the OEM.Right now I'm cleaning and preping to paint the engine.Hopfully I will fire the Mac up in a couple of weeks,no hurry now, I've got all winter.I'm trying to come up with a paint scheme for the bird,something on a southern states motif.Any way thanx again for yours and every one else help,I know it want be the last time I cry for help.
Regards Sonny

[Chuck Irby]

Jose, Good for you! I saw the pic above and thought it was a recent one. Is everything going well with you Jose? What's the latest with the crow hops?

Sonny, How's everything going with you? I'm really glad you're still pleased with that machine. Mr. Gadget's CDI has got to be a big improvement. That's a smart move on your part. Remember now, I want to fly that machine some day, Okay?

[Sonnyj]

Hiya Chuck
Having a few problems but in my line of work problems are the fun part,and I'm having a blast! :D Turns out the fuel pump was bad,and I can't get parts for it but I can get a new Mikuni for 35.00,thats probably better than the OEM anyway. :cool: Got a kit coming for the carb,hope to have her fired up soon.
Good to hear from you Sonny :)

[joeheli]

Thank you Sonnyj. I did it my self with spray paint. I use to pain with airbrush
So I try it again on my rudder. About the CDI, That is the best thing you will do... I use to have alote of problem with the "MAC ATTACK" some times will start, some time it won't. Other thing if you try to idle with out the CDI system it will quit. Now, With the system is easy to start and belive it or not. It idles like a monster Harley Davison. You really will enjoy it!. Chuck I am already flyin all the way strait line at 7' and 10' and on the end doing my landing. I have to tell you does blade are incredible they have alote of inertia and lift I really recommendet to any one . They feel like McCutchen blade maybe is becouse it has the same airfoil.

[joeheli]

Sonny I will recommend to eliminade the mecanical pump ( if you still have it) and the OEM pump use the 2 way Mikuni fuel pump.

[Sonnyj]

Jose are you using the single float Holly?

[joeheli]

Yes. Iam..

[Chuck Irby]

That doesn't sound too bad Sonny. How far is it to the instructor?

Wow, Jose, it sounds like you're doing GREAT with the flying. I am really happy for you, my friend.

[GyroRon]

Sonny..... looked all over for you at ROC, I take it you didn't come cause the engine was't running. Too bad, me wanted to see that gyro and meet you.

[Sonnyj]

Hiya Ron sorry I had to miss meeting up with all of you.Actualy I intended too show up even if the motor did'nt run,I'd realy like to have a good todo list,but I guess it will have to wait.Things Just got too buisy around here,you know the old sayin"ya gotta make hay while the suns a shinin".Maybe I'l get a chance too visit you at the hanger this winter.

Hiya Chuck I'm not sure now Scott was saying the guy that lives closist to me moved of to Arizona are some where,so I reccon I'm on the hunt again.

[joeheli]

Sonnyj, This is Rick engine. As you can see the pump is a two way Mikuni pump, He use (2)Two way Mikunis, One on the top of the CDI and another on the bottom of he engine. He close one of the exit on the 2 mikuni
to compress the pressure to the only exit that is open. Does exit get together on a "T" close to the carb. That is the prosidure that I was tryin to tell you.

[Sonnyj]

Thank you Jose that is very helpful,the only change I would make is,I would put the filter ahead of the pump {between the tank and the pump}it most likely won't make any differance but any little bit of t tape or trash could stick in one of the check valves in the pump cousing it to guit.
Thanx again Sonny

[Sonnyj]

Well I got the new Mikuni fuel pump,and installed it,rebuilt the carb,cleaned the plugs and checked for fire[nice and blue],checked timing ok,but she still wont start.Next thing is to get rid of the shilded plug wires.Can anyone give me the Champion part# for the replacement plugs?
Thanx Sonny

[joeheli]

Champion 506. They call them too the Champion D6.

[joeheli]

The Mac engine, if you don't understand them they are going to give you a hard time
to stard them. Whend you get the wright combination that is the one that you are always going to use intill you change the timing . Tell me what you do to start the engine...

[Caribean_gyro]

stop, beore you change the plugs. If I understand correctly, you have fuel and spark? and timing is done as per CDI booklet.

I will say priming sequence. If you have all of the above and cdi is ON, what is your sequence 2 to 3 pumps and 1 prop turn? etc. This have to be right. please elaborate what you are seing so we can do a telepatic diagnostic.

now 5 cents can make it start. "SAFETY MATCHES"

ChuckP

[joeheli]

That is a good one Chuck :D ! Yes, like Chuck just said, priming sequence is the key of any MAC starting. If you do it wrong it will never start intill you get it wright.

[joeheli]

Chuck I think he dosent have a CDI. I think the problem is the "mac attack".

[Sonnyj]

Good mornin
Thanx Jose Ill get the plugs today,Please elaberate on the phrase "Mac Attack",whats happining to the engine. :confused:
Hello Chuk
Jose is correct I do not have cd ignition at this time,I suspect the plugs are fouling becouse the old wires are leaking inside the sheilding.I'm changimg them to the 8mm silicon stainless core.If the old girl sounds good then I will spring for the CDI,if not it'll have to wait till after the overhaul :eek:.Please tell me about "priming" the engine.
Thanx Guys Sonny

[joeheli]

Sonnyj The engine is not the problem ( I THINK!!). The problem is that if you have to understand the engine or it will never start. I never had any problem with my engine. About the wire I don't think that is the problem because you say that you saw the blue spark commig out the spark. If the timing is wright (.125) the problem coud be like Chuck say "priming" or the gasoline is not getting in to the engine.

Take out the carburetor hat and look inside there, to see if when you open the throttler you see a big line of gasoline getting in to the chamber. If you see it then gasoline is not the problem.The pump is new so is not the pump. You already check the spark plugs Did you check the engine compresion?, verify if theres no compression leak... humm :rolleyes: .... I thing the last thing is primming. For example
I prime my engine this way:

First Check that the switch is off , and throttler close. Prime the carb with the manual pump until the manual pump is very hard. Then open and close gradually the throttler 2 times. Spin the prop one time. I then open and close again (2 more time the throttler gradually) spin the prop again. Verify that you close the throttler .Switch on. And on the third hand start or less it shut start. This is my combination, yours can be different. If you over floted with gas you have to make shure the "SWITCH IS OFF" open the throttle and back up 20 times the prop. Then make shure " YOU CLOSE THE THROTTLE" then switch on and try it to start. Please don't do this alone or tide the gyro..

The "mac attack" is what is happening to you . You have to know this engine and all this procedure. Because if not it will not start. When you get to know them and get a CDI you will enjoy your engine for a long, I will garantee you that.

OH! tell us how do you do your priming to see if we can help you...

[DanR]

I belive my Mac would start with the CDI even if I poured a gallon of gas in the carb lol, but i have a problem with the engine. I recently pulled the cylinders off and inspected everything I could and all checked like new I belive its a new engine from apperances, the problem I am having is one cylinder apears to be running hotter than the rest this cylinder is on left hand side facing the prop from the rear (No. 2) I have increased the size of carb jet to the point the engine is running very rich and still the plug is white the rest of the plugs are in the brown to tan color. I dont know what do next there are no cracks in case or cylinder that I can see, what could cause this? I removed the cowls and running it without them could the prop be pulling the air differently over the cylinder causing it to run hotter? One thing I have noticed is the other two cylinders near the mag have much more compression than the other two when pulling the prop through maybe they just aint broke in yet.

[Rick Whittridge]

Dan, it sounds like the rings are not seating in.
72 or 90 hp?
Did you replace the rings?
How long have you ran the motor?
Crank seals rubber or leather?
What oil are you useing?

[DanR]

Rick, I have a 72 hp Mac, no I didnt change the rings when I pulled the cylinders, like I said the engine seems to be new I have mostly ground time on it just up and down the runway It may have possibly have three tanks of fuel through since I had it. I noticed the white porceln on the plug when I changed to your CDI, I am using Blue Marble oil in it now, it idled about 2 to 3 hundred rpm faster after changing to Blue marble had to slow it down. I think I have the leather seals but not sure without tearing it down, I guess thats the next step replacing the seal in the nose or replacing that cylinder maybe by next spring i'll get the dang thing right but rite now am getting tired of messing with it all work and no fly. Thanks

[Rick Whittridge]

Dan, if cyl 1 - 2 feel differant in compression then start looking there.The old leather seals should not be used. When replacing cyl base gaskets you should beware that some gaskets are cut too big.If you place the gasket on the cyl,line up the holes with cyl & see if the gasket protrudes inside of the induction tract.This can reduce the flow of fuel into the cly.I always trim the gaskets to fit the cly in this area. Cly 2-4 run the hottest. Of all cyl that have caused me problems it has been cly 2!

[DanR]

Okay Rick I think the problem of that cylinder (no. 2) running hot may be the center bearing flange, I have a crank and case sitting here in my lap lol and looking at the no. 2 hole in the case looks like it could benefit from some porting and polishing to let the air into port when piston is down at bottom of the stroke there isnt much room for air to flow into the port. Does R&D have the rubber seal or is there something at NAPA I could replace it with?
Thanks Dan

[Caribean_gyro]

#2 is the closest cyld to the seat. I run hotter. Now what you call hot? Are ou using cooling Cowls? You mentioned new engine? Perhps remanufacture? The piston shall be camgrind to allow expansion with heat? Also the temp is 350 , 450 ? The temp problem is at ground or flying. There are too many things betwen timing , oil brand and ration, crankcase seal etc that could affect temp. let us know the temp reading and testing done so we can be a bit of more help
chuckP

[Caribean_gyro]

dan I didnt saw the cowling note. R&D has the gaskets, I use Yamahabond gasket seal. I like it becasue when you pull the cyl apart it breaks the gasket evenly. SO cleaning is better. But I still will like to know what is the temp. I have sen guys here fly at 450 F' and no problem.

Now can you see all the little marks inside the cyl? do yu see some kind of peling. ALso what is the fuel to oil ratio and what brand.

we use jets between 65 and 66.

chuckp

[gyronutt]

can one use form a gasket instead of paper gaskets on the cly's?what are the color marks on the rods?

[Rick Whittridge]

Guy, I would`nt try PERM-A-TEX as a substitute for a cly gasket on the mac!If you notice that the case & the cly have groove cut into the surface area to keep the gasket from sucking in or blowing out. Any void in the surface between the two parts will drawn outside air into the cly causing a instant lean condition.Some of the earlier Mac rods where copper plated (this is good) to help with the HEAT! Most all modern day 2 strokes plate the rods with copper the same way. I`ve seen paint marks also, must be during manufacturing for identification or completion of maching?

[gyronutt]

thanks rick,where does one get a gasket set?i rented a hub puller from r&d so i'm just getting to work on it,i found a set of piston&jugs from greg who had them for 30 years,not sure if the piston need to go a certain way?i ordering a mac rebuild book.

[Rick Whittridge]

Guy, R&D or Ken Brock can help with gaskets.

[DanR]

What I am gonna do is put differential compression checker on it and then I can determine exactly what is going on with that cylinder. I dont have a CHT on it but will have this week, also there is a tapped plug in the 1 an 2 crankcase area so Ican also check that area for leaks and such. I am suspecting that rings are not seated so I may change to a nondetergent oil and see what happens. Thanks everybody for yall's help

[Caribean_gyro]

First we are talking about an engine that dont start? right. SO dont change oil yet. COmpresion test is ok but you have also to sealed the exasust and blow 80 pounds in the block. This will insure you dont have a bad gasket on the crankshaft ends.

Now you dont have a CDI so you must make sure that the magnet are fully charge. The rotor dont have natural magnets. then the distribution cover tend to create rust on the nails whre you attached the cables. Inspect them. Second USE WIRE CABLES. dont use anu facy low noise cable. Go to a speed shop and you can buy it in feets. a nice cable with a nice strand of cables. the timing is aorund 22' BTC , make sure the inmpulse coupler is freely engaging.

buy no means run the mag without plugs, this ruin the coils. the spark is very low to see, hold the plug and feel the spark. I know is a rush but is the only way.

Now once you have spark at least in 1 coil the engine should start. Oil well if you use aviation it has to be non-deterdent. Priming 2 pump 1 roation of prop, 2 pump another rotation of prop. then 2 rotation more and switch on. This vary with engine some engine need 3 pumps and some only yone. depent of carb and if they are super mc.

still feel the matches is faster but keep trying and let us know what you see and did. Is hard to operate form far away
Chuck

[DanR]

Okay I'm back lol, the internet went down on me. This engine starts and runs perfect with the CDI now the problem is one plug is running hotter than the rest, its not blistering the porceln electrode but it is white where the rest is tan to lite brown color and this at a fast idle sometimes at almost full power for a short time on the ground, I ran the differential compression test the cylinder is 80 over 80, holding the prop where the crankcase is sealed and pressurizing the crank case I hear air escaping through carb the front seal is sealed good but now I am back to square one noticed the lower motor mount brackets are broke so I have fix that before anymore engine work. If these problems would have manifested themselves in the air I fear what may occured just about to the point if any more problems I am gonna cut it up for scrap before someone gets killed.