084 mods

[chuckitt]

We converted the intake to bolt on the solex carb. We call this a big plenium intake. It could also be called a raised plenium intake. It may cause the engine to run lean and a bigger jet may need to be installed.


Thanks, Chuck

[chuckitt]

We changed the spark plugs and wires to automotive. We used the ACCEL # 3009 which are 7mm copper core wires with 90 degree boots. The plugs are Autolite 386. Set the plug gap to .020. We took the wire cap off the mag and cut the threaded bushings off and reamed the wire holes where it will fit over the mag block. The 90 degree boots we put on the mag end of wire came from the ACCEL wire set # 4041K. We had plenty of these left from wiring the v6 motors. To hold the wires on the mag, we drilled and taped a 10/24 thread in the center of the wire cap and bolted a pcs of polymer to keep the wires from coming off. We also put a #4 sheet metal screw in the end of each wire.


Now the Spark Plugs cost less than 2 dollars each and can be purchased at most auto parts stores.
Thanks, Chuck

[Duane Scarborough]

Chuck

That's good info to know.

Do you know if anyone has tried using a Kiehin CV side draft carb like used on 1989 and later Harley Davidsons on an 084? I think one could be installed on the original intake, in the original carb position fairly easily.

Just wondering....

Thanks,

Duane

[buster]

That plug wire conversion sounds like a good idea Chuck. I'm sure I'll be copying it the first time I need to buy one of those $10.00 spark plugs.

Let us know how that carb. mod. works out!

Thanks, Dave

[Duane Scarborough]

Buster,

I've ordered a couple sets of plug wire adapters from Richard Harris on the Yahoo 084 group. These are supposed to let us adapt the shielded military magnetos to use 7 or 8 mm high performance plug wires and automotive spark plugs.

I'll let you know what I think of them when I get 'em.

Thanks,

Duane

[Duane Scarborough]

Buster, and all,

I've got them. They're actually pretty simple. I'll try playing with them over the weekend. After looking them over, I wonder if we couldn't easily modify the original brass mag nuts to do the same thing.

I'll let you know what I learn.

Thanks,

Duane

[airhead]

Well,

For the first time ever we are doing the turkey thing tonight. One of the girls had to travel some distance to be with his folks so we decided this would be best.

Being the busy body that I am, ( when i'm well ) I got bored and and decided to give you'll, and me , a Thanksgiving present. It isn't complete but I think I have enough for you to figure it out.

So, don't throw away your shielded wires They will come apart

Here's a picture and you may come up with a better idea than I did before I can post more. It's simple so don't try to make it complicated

And by the way, HAPPY THANKSGIVING EVERYONE

[Duane Scarborough]

airhead,

I hope that you had a nice Thanksgiving celebration.

I still haven't got around to trying those plug wire adapters that I bought.

But I figured it'd probably be just as easy to modify the originals for the same purpose.

It sounds like you've came up with something there....

When you get a chance, please post a how-to-do-it for the rest of us.

Chuck,

I've meant to ask before, but just never did. How'd you come up with the Autolite 386 plug? I've searched for cross-references for the original shielded plugs to a conventional plug, but haven't found anything.

Thanks,

Duane

[chuckitt]

We have been using these Autolite 386 plugs in aircraft engines for years. Also the Delco C87 is a good plug. They quit making the Delco C86.
Thanks, Chuck

[brlcla]

Since I am waiting on a few adjustments to my boat.... I of course have been researching.... You know the "What could I have done different?" question you always ask yourself after you get the boat you wanted. But I am very happy with my EVT Stage 2 American Airboat... may step up to a Stage 3... but that is for later

So here goes a thought... After looking at Rotax engines I noticed they run dual carbs, one for each side of the motor. Has anyone considered fabricating a set of plenums for the 084 to allow dual mikunis to be bolted up to the 084? Also what is the displacement of the engine, 84ci? I also heard that EVT has an 084 in their hands taking a look at what they can do with it... I have heard a few rumors

[Duane Scarborough]

brlcla .

You're correct about the 4A084 being 84 ci.

I've read some on the Yahoo user's group about folks trying different carbs.

The Solex seems to be a fairly common setup, since it was designed for a similar sized 4 cylinder engine.

Everyone I know that's tried it has had pretty good results. Not to say that you idea may not work better.

We'll keep our eyes and mind open....

Thanks,

Duane

[Papee]

Here's my new carb

[Duane Scarborough]

Papee,

You know better than to throw out a carrot like that without more info.

I'm still convinced that a Keihin CV carb, like used on a Harley would work pretty good. It's also a side draft. That's partly why I held on to my original manifold when I ordered the modified one from Chuck.

But I'm going to try the Solex first.

So, spill the beans...

Thanks,

Duane

[brlcla]

That carb appears to be a Mikuni VM Round Slide...

[Duane Scarborough]

brlcla,

I think you're correct.

Papee,

Tell us more. Why'd you choose this carb?

It may work just fine. But I'd like to know how/why you chose it to try.

Duane

[Papee]

Ok, as we all know I pretty much have my own drummer I march to.

This is a Dellorto VHSAB carburetor, it is a racing version of their VHS series carbs. Why? I am trying to get the best fuel mileage I can get with the best performance. This carb is very adjustable to each application and is polished for better flow. I plan on cutting the intake shorter and polishing them up also.

I just wasn't happy with the mods on the intake for the Solex carb. I'm looking to get a better delivery system to the cylinders. I'm looking for specific results improving the response, a few more rpm, and the adjust ability to get the right amount of gas without losing the fuel consumption I have now I know I will use some more fuel to an extent but my major quest is for better fuel flow and better throttle response.

[Duane Scarborough]

I hate Ebay.

I just "won" a bid for a Keihin CV side draft carb, from a 1200 Harley Sportster. Dammit.

I know these carbs inside and out from playing with them for years. I knew that I was going to try one eventually. In my defense, this bidding was into the last 5 minutes, and it was going for so low that I just "had" to bid on it.

I ain't complaining.

At least I have another option. Dammit again. I'm sure glad that I hung on to the original intake manifold now. Or I wouldn't have nothing to play with.

Thanks,

Duane


Papee, Yeah, I guess that I march to a different drummer myself. I'm not sure if that's a good thing, or a bad thing. I'm pretty much tone deaf.

[Sandman]

It looks allot like a mikuni for a snow machine... just polished. What size is it Papee?
I don't really know enough about carbs to do allot of modding with them... it would be nice to run dual Mikuni's but I wouldn't even know where to begin... I think I would need to go with the most common set up for my 084... oh yeah.. I've got an 084!! Whoohooo!!

Sorry that just slipped out!!

[Papee]

It's actually a Dellorto VHSB34, it is a 34mm all jets can be interchanged.

Choke : Ø 34 ? 36 ? 37 ? 38 - 39
- 2 - 4 stroke
- Flat throttle valve
- Inserted choke
- Independent starting circuit
- Idling system with jet and air adjusting screw
- Main circuit with mechanical mixture adjustment by means of conical needle
- Versions with idle adjusting screw on the left and/or on the right
- Bowl with the possibility to assemble independent floats
- Ø 44 elastic fitting connection
- Air intake connection Ø 64 for unions assembling and special for ?free? suction