1982 430CR Performance Mods

[Kartwheel68]

Yes, it would. Harry Klemm also covers why it is a bad idea to go to a bigger carburetor, very few bikes will perform better with larger than stock carburetors. He covers why doing plug readings with current pump gas is a waste of time, oils, fuels, air leaks, pretty much everything you need to know. Harry is a genius and if you want to learn how to tune two stroke engines there is no better person to read.

 

[Bigbill]

I had the 40mm carb working on my last 390cr. I leaned the jets and added the UFO and leaned the needle jet. It ran awesome but not for a beginner rider. The 390 I just bored, new crank bearings, new piston, seals and gaskets. A made a adapter plate to fit the larger 40mm manifold. I have another correct needle jet I used but I can't remember the jet size. Old age brain fade. But it can't be that hard I did it once already. I think properly fitting the UFO is very important. It's a tad large(higher) I sanded and filed the wedge so it fit perfect. Don't forget to match the transfer ports to the case. And match the base gasket to the case and cylinder. Then match the reed block to the cylinder. Lots of porting to do or should I say surgical porting. Go slow do it right.

I have the mossbarger complete intake coming with a Yamaha 465 boost bottle. I have a plate to machine to install the fitting for the hose for the boost bottle. This way nothing can't be put back to stock. I'll use the 38mm carb with a UFO.

 

[justintendo]

if you really want to emulate the crappy yamaha setup, why not just thread, weld, or epoxy a tube to a stock manifold like this? plenty of these on ebay if you still have the rotted and expensive to replace one piece rubber manifold.

guarantee with a 40mm carb and a bottle it will have less bottom end power than a well jetted stocker. definitely wont run as clean as a stocker thats been lectronified. yes, i know you are going to use the ufo stuffer. some carbs are designed to not need it you know.

 

[Bigbill]

The mossbarger reed block needs a 3/4" spacer block. I can machine the npt hose barb. The newer reed block I have coming it's threaded from a 500.

 

[dmcoz]

I'd like to see the pic of the exhaust port.

I open up the exhaust port, arch the upper part of the port and raise it a tad. Then widen it a little like 1/16" then polish it. Once you do all the porting the engine is right there on the throttle. There is no lag when you twist it its response is right there. You will see the difference.

 

[dmcoz]

How many different stages of porting is there?

At least 4

 

[84scrambler]

What I can't believe is this thread about boost bottles is this long... Do you want to believe they work just because it looks cool or something ?
If they worked, every bike would be sold with one.
Hot rods in the 50's were totally different seen, You had to experiment because the stuff was not for sale then and very few really knew what made horse power during this new era. That was a totally new up and coming fad that lasted a long time and still exists to this day.

 

[ct cr430]

Hi Bigbill , you asked about my jetting so here it is . But first here is my setup . Cylinder has transfer port mismatch to cases cleaned up and ant mismatches with mossbarger reed block removed . Asche pipe with shortened stock silencer . All new bearings and seals . Stock 38 vm Mikuni carb . Timing set to 2mm btdc . Ngk b8 ev or similar non resister plug , want to say b8evg . The mossbarger has 2 stage reeds from a Yamaha banshee it it . I was using this , main 430 , pilot 40 , slide cut to about a 3 from stock , r4 brass jet needle and 6d3h needle on leanest clip . This ran ok but was rich down low and into the midrange while using pump 91 octane with ethanol , maxima k2 oil mixed at 40 :1 with an once of start on to 5gallons . Then while up in Vermont I bought 5 gallons of ethanol free 91 octane and the bike ran like cr$p ! Time to re-jet . Right now here is what I'm running , slide cut to about 3 , pilot 40 , main 450 , r0 jet needle and 6d3h needle on clip 3 . I also bought a 6d2 needle but haven't tried it yet . The first jetting specs where rich down low and sluggish into and thru the midrange , had trouble getting out of corners . The 2nd set cleaned that right up . Still trying a few things but that's where it is right now . My riding is all below 2000' .

 

[Bigbill]

Thanks they arched the exhaust port like I been saying.

Thanks, ctcr430 for the specs. Have you thought about installing a UFO in the bottom of the slide.

With the talk ongoing about the boost bottle I think the carb jetting has to be spot on in order for it to work. There is so much involved to tuning it correctly. Some will get that to the point it's 90% jetted correctly. That last 10% can kick your butt. And some will never get it and give up. Remember once it's close jetting wise you need to tweek the needle and ajust the balance screw last just to clean it up. Write everything down. Having a good needle and seat that doesn't leak and the float level set right is a good starting point. Go slow, don't give up. It may take going through the jetting process two or three times to get it close to that 90%. The different circuits overlap. One circuit can be rich and mess the process up. Once the pilot jet has the balance screw between 3/4 to 1 1/2 turns ( I like it at 1 turn or close) it gives you room at the final tweeting to go either direction.

 

[Bigbill]

What I can't believe is this thread about boost bottles is this long... Do you want to believe they work just because it looks cool or something ?
If they worked, every bike would be sold with one.
Hot rods in the 50's were totally different seen, You had to experiment because the stuff was not for sale then and very few really knew what made horse power during this new era. That was a totally new up and coming fad that lasted a long time and still exists to this day.

Did the works bike or pro circuit bike use a boost bottle back then? Is there any history on it? I have learned that every change we make adds up. To the end point were adding up horsepower. One change doesn't really add that much. With porting we need to do it all. The engine has to breathe it's free horsepower. You won't believe how fast the engine reacts to the throttle. All the changes work together. Arching the exhaust port changes the port timing. The exhaust opens sooner.

On the piston ported two strokes we cut 1/8" from the bottom of the piston. Then raise the exhaust port and lower the intake port. (No reeds)

 

[Bigbill]

What I can't believe is this thread about boost bottles is this long... Do you want to believe they work just because it looks cool or something ?
If they worked, every bike would be sold with one.
Hot rods in the 50's were totally different seen, You had to experiment because the stuff was not for sale then and very few really knew what made horse power during this new era. That was a totally new up and coming fad that lasted a long time and still exists to this day.

I think everyone here deserves a pat on the back just for keeping it civil. It's a great discussion. The question is does it work or not. I don't know.

 

[ct cr430]

Somewhere in here there is a post showing a procirciut add listing the then available mods for husky's . Thanks to others who posted thier settings before me to get me this close . I did think about the ufo but just not at this time . One thing I hope to have pointed out is there are a lot of variables involved , what works for one person may not for another .i believe that to use somebody else's jetting you need to know thier set up also and as what I found out , what fuel is being used .

 

[Kartwheel68]

I think everyone here deserves a pat on the back just for keeping it civil. It's a great discussion. The question is does it work or not. I don't know.

No, it does not work, and you have been told repeatedly why. The Pro Circuit bikes did use them but the European bikes did not, and none of the factory enduro bikes used them. PC used them because they sold them, not because they worked.

 

[GaryM]

No Bill no Please! not at all on raising the exhaust port any higher on 430. Its at 39mm on CR starting 82 and 40mm from top on the WR and. If you have the top of port opens too
soon on the 430 you can get incomplete ignition and a hot head pipe on the 430. ( i have hot head pipe now at 39mm ) The ignition or head pipe on the 430 is hot , real hot now at 39mm this would reduce power.

This setting is at a balanced setting at it limits of port timing design I guess you could have tunnel boost exhaust on the same level.( like 84 250 WR std ) but I don't know if to close to stud holes

Please no more advance other than the 2.2 on the 430. It still is a risk to get kick back for most ignitions. Could and will break your cases. Again motor will run hotter. Not good for engine life.

Boost bottle don't work noted by expects. Wasting time and money. Single cylinder cranks can be trued and square and smooth. Single Cylinder Cranks cannot be Balanced - class given by crank restorer from UK major shop ( took this class three times) Multi cylinder cranks engines can be balanced because they have something to be balanced to.

Remember Rick Horvart to me. Don't overdo it. the 430 can be improved yes but at the expense cost of heat wear and tear and exhaustion as you try and control the power band when riding.

 

[GaryM]

Rational porting and mods. Mossbarger reed block, clean up standard ports and transfers. Basically match iron liner opening and cylinder.

Electrex ignition. earlier starting and retard circuit to protect cases and foot. It runs better too through rev range too.

I added a Geoff Morris pipe. Nice surge in mid range. just really wanted to match the 430 bike in the VMX mag. a few years ago

With Mossbarger my main jet setting is rich even at 415 may go back to 410 or lower. These are all done


Will look at a couple Carb options for example the UFO mod is really for low end so it it helps starting and cleaner pick up down low.

Or Lectron Carb , for even better starting and low end. Maybe ad a mini weight to internal Electrex ignition or full external one just to try.


(( Note its me that needs to get ported. Lose 50 pounds and ride my lifecycle and lift my weights. I am looking at those across the room right now. ))

 

[Kartwheel68]

Exactly Gary, keep it simple. As I noted at the beginning of this thread, there is a very good reason those official Husqvarna porting specs are subtle.

 

[justintendo]

the swedes knew what they were doing creating the powerband they have...
the real limitation are the cylinder studs, reed design, no pv...
like said, the best port work is doing what husky would have done if money and time were not an issue. matching, cleanup, surface finish. maybe some dome work to really optimize fuel usage..cringe at the thought of advancing timing..better to gear it down a tooth or two.

 

[Kartwheel68]

And Gary made a good point, if you want to know what the greatest bang for the buck you can spend to make your bike faster, its a gym membership for yourself (me included), not porting or boost bottles or bigger carbs or two stage reeds or anything else to do with the bike.

 

[Bigbill]

I feel is we advanced the port timing it's useless if we don't advance the ignition timing a hair too. I've done it before.

When I was hammering the bike it's better than a gym membership. The bike works every muscle group even the brain in thinking.

 

[dmcoz]

Guys I think some of us are missing the point...most of us no longer ride for sheep stations !! (except maybe the kiwis ! ) we first just like to make our bikes look good and run reliably. Then some of us like to make our bikes look like what they did in the 80s and if the PC bike had a boost bottle and we want to make it look like this, then we put one on. whether it makes a performance (or not) difference is largely irrelevant as really do we think we can notice the difference ??