starting point

[quadracrdad]

I need some advice on where to start jetting. I have a malossi big bore, stage six 44mm crank with a 85mm rod, 28mm keihin, haggarty intake with stage six reeds,malossi over range variator, stage six adj clutch with over range pulley, and stage six pvl. Engine was just rebuilt with porting and polishing. Hetrick gen III pipe. Any advice is greatly appreciated.

[mmsoup]

Where is the Air filter located? Length and diameter of intake will make a big difference

[quadracrdad]

Airfilter sticking out on end of carb.

[Coley'sdad#8]

Now I just can't help to laugh at that response , you asked mm
:D :D :D :D
I think he means is your's a rear facing intake and or do you have the Haggerty intake

[Logan #34's Dad]

His post clearly states "Haggerty intake". Lol. Don't quite understand mm's statement either. I'd say - really?
Anyhow, I'd start with a 42 pilot, need clip in the middle, air screw 1 1/2 turns out from screwed all the way in, 135 main. Amsoil Dominator mixed 50:1. The main should be a little rich but that is okay. Just work from here and good luck.
Maybe someday someone will make an electronic fuel injection system for these quads and then we'll only have to worry about the cvt. Fun!

[redonkulousruntsracing]

Funny you say that, I know a couple of guys working on an EFI set up right now. They got it running on a 70 and are trying to get it dialed in for the 90's. But the bad news is that initial pricing looks to be over a G!!

[asadad00]

Originally posted by quadracrdad
I need some advice on where to start jetting. I have a malossi big bore, stage six 44mm crank with a 85mm rod, 28mm keihin, haggarty intake with stage six reeds,malossi over range variator, stage six adj clutch with over range pulley, and stage six pvl. Engine was just rebuilt with porting and polishing. Hetrick gen III pipe. Any advice is greatly appreciated.
i have found that when using a ported cylinder your best recommendations will come from the guy doing the porting , i would trust his opinion .

[mmsoup]

Quote

"His post clearly states "Haggerty intake". Lol. Don't quite understand mm's statement either. I'd say - really?"


No problem smartass

We run two Malossi Big Bores with Stage 6 Cranks. One has an 85mm rod and an untouched cylinder and one has a 90 mm rod with a CGR ported cylinder.

We run a Haggerty with the minarelli adaptor on a Trackside Pipe with the uncut cylinder and a Haggerty with a KX65 boot on a Mach 1 on the CGR cylinder.

(By the way Rocky, we place our reed cages on the carb side on our Haggerty's)javascript:smilie(':eek2:')

We run GNCC's and have a 2" snorkel that runs up under the cowl on both models and runs approximately 12.5" with a 90 degree bend at the carb. (Both Motors are set up with Keihin d-slide 28mm's)
We run a TwinAir because it flows better than the K&N style for some unknown reason and we run a 162 Main with the Trackside and a 178 main with the Mach One. The long intake slows the air velocity down and the bigger jets are required to allow for the proper fuel air mix.
Both bikes like a 45 pilot and I run one with the needle clip one position rich and the other in the middle.

The reason for my question was simple, If he's running a snorkle, your very sensible MX settings will burn the motor up in a hurry. If he's running a typical MX set-up there would be no need to offer comment.
But what the F#$@ do I know?:eek2: :eek2: :eek2:

[Logan #34's Dad]

I wasn't trying to be TOO much of a smartass but your post was a little misleading. You stated that the length of the intake makes a big difference. The Haggerty is what it is. Your comment was not real clear - like you were asking how big and long the air filter itself was..... You state that the length of the intake makes a difference. The snorkle is not an intake. You never mentioned a snorkle.

[gdr8]

I hope you don't mind me cutting in on your post but this is something I have been working on myself. I don't have all the same expensive stuff but I have a Mallosi big bore with a 45mm crank built/ported by Hetrick for MX racing. I have a 30mm D slide with a stock like intake with a 1/4 spacer under it. The air cleaner is stock facing foreward, I am using a WRH pipe he says is built for the Mallosi big bore setup. We run local MX races. It seems to run good but not great. I am at a 45 pilot and a 138 main. Any idea if I'm in the ball park with this setup? Money is a little tight right now so buying a bunch of new parts is low on my list.
Any tunning info would be great!

[Logan #34's Dad]

Of course where you live make a big difference do to the air density but, I run a basic intake also because I don't like how the Haggerty puts the carb so close to the riders knee. Anyhow, we are running a 30mm D-slide with a Uni filter. 42 pilot, 132 main, needle clip is in the second grove from the top. Amsoil Dominator mixed 50:1. If I'd guess, your performance issues are due to the pipe. Hetrick's newest 90 pipe will make a Big Bore rip. As will the new MaxRPM pipe. Clutching could be a factor as well.

[mmsoup]

OK Rocky, you have a point

On the Malossi that was fitted to a 45mm throw crank, Where does it run best and worst?

Just Curious because that brings the displacement closest to 90cc but I was wondering about the port timings etc.

WRH pipes seem to be good most of the time but Rocky is right, the Hetrick GEN 3 is excellent. The Trackside is good (Kinda loud) One of the kids at the GNCC's has MaxRPM's pipe and it is ripping
One of the kids is running a 2Fast pipe and it rips, Kira's Apex has the Mach 1 and it is hands down the best pipe I have ever run on one of these, but it costs an arm and a leg.

Try moving to at least a 1/2"spacer to clear the reed cage from the transfer tunnel and make sure the intake walls are the same diameter as the carb (intake side)

What ignition are you using? We use the Stage 6 PVL on both of ours and it has eliminated the ignition as a trouble source.

The biggest gain we have seen though came from the Mach 1 pipe.

[nordic quad]

Originally posted by redonkulousruntsracing
Funny you say that, I know a couple of guys working on an EFI set up right now. They got it running on a 70 and are trying to get it dialed in for the 90's. But the bad news is that initial pricing looks to be over a G!!

Actualy Apex has a working prototype with fuel injection but as they have other stuff to work on i doubt we will see it in production anytime soon.
Stein A

[nordic quad]

Apex fuel injection as it was shown at the Eicmashow in Italy.

http://4hjulscrosser.dk/Oplevelser....asp?showpic=1&fieldID=520&fieldnr=3&menu=70&submenu=35&hidesub=yes

[Coley'sdad#8]

the F.I. on a 2 stroke is going to be a more complex system than what is on the 4 strokes. they are going to have to be an exact pre determined fuel mixture before mapping.

[Logan #34's Dad]

I've done "some" research on this 2 stroke efi system. There is a group of former Colorado University students that are changing the world overseas. They developed a system for the little 2 stroke taxi's. There is a very smart fella that has one developed for us BUT when I spoke to the AMA-ATVA they said we could run it but ONLY in the Modified class. Ugg.

[gdr8]

Originally posted by gdr8
I hope you don't mind me cutting in on your post but this is something I have been working on myself. I don't have all the same expensive stuff but I have a Mallosi big bore with a 45mm crank built/ported by Hetrick for MX racing. I have a 30mm D slide with a stock like intake with a 1/4 spacer under it. The air cleaner is stock facing foreward, I am using a WRH pipe he says is built for the Mallosi big bore setup. We run local MX races. It seems to run good but not great. I am at a 45 pilot and a 138 main. Any idea if I'm in the ball park with this setup? Money is a little tight right now so buying a bunch of new parts is low on my list.
Any tunning info would be great!

To answer a few of the questions; The cylinder has been ported and matched to the cases, running about 160psi compression. I am using a anolg PVL, we are at about 500 to 1000 feet above sea level on the west coast. Clutching is a Delta with a 2000 bkack Koso main spring and black trio springs that are engaging at 6200 rpm. Front is a Dr. Pulley with 4 gram sliders. Belt is a 787x16x30. For gearing I have 28/13 trans gears and a 32 rear sprocket with a 19 front. So maybe its ok as is. I am compairing the power to a WRH built 107cc that I have. I built this motor so we would be legal in a 90cc class. The quad seems to pull pretty good on the top end and not too bad on the bottom end. I was told that there would be a noticable power differance between the two motors and there is not.

[asadad00]

Originally posted by gdr8
I hope you don't mind me cutting in on your post but this is something I have been working on myself. I don't have all the same expensive stuff but I have a Mallosi big bore with a 45mm crank built/ported by Hetrick for MX racing. I have a 30mm D slide with a stock like intake with a 1/4 spacer under it. The air cleaner is stock facing foreward, I am using a WRH pipe he says is built for the Mallosi big bore setup. We run local MX races. It seems to run good but not great. I am at a 45 pilot and a 138 main. Any idea if I'm in the ball park with this setup? Money is a little tight right now so buying a bunch of new parts is low on my list.
Any tunning info would be great!
I agree with logan34'sdad a change in pipes would be a big improvement max/rpm and gen 3 will make a big difference but as mmsoup said the mach-1 is no doubt the best money I ever spent , although it will cost about 100 more, it will be the best 100$ upgrade you will ever make.

[gdr8]

Originally posted by gdr8
I hope you don't mind me cutting in on your post but this is something I have been working on myself. I don't have all the same expensive stuff but I have a Mallosi big bore with a 45mm crank built/ported by Hetrick for MX racing. I have a 30mm D slide with a stock like intake with a 1/4 spacer under it. The air cleaner is stock facing foreward, I am using a WRH pipe he says is built for the Mallosi big bore setup. We run local MX races. It seems to run good but not great. I am at a 45 pilot and a 138 main. Any idea if I'm in the ball park with this setup? Money is a little tight right now so buying a bunch of new parts is low on my list.
Any tunning info would be great!

Thanks everyone for all the info, I will try the 1/2 spacer under the intake and see what that does. I will also look(probably for a long time) for a used Mach 1 pipe as that seems to make the best power from all the feedback. Until then I'll be working with my rider to impove his skill level. Probably the cheapest and most important improvement I can do!!

[mmsoup]

That rider comment can start a whole new thread....
To clarify, we are using the "New Version" Roost Mach 1 pipe. Marc was selling US made versions a couple of years ago. I have run both and the Roost pipe is the real deal
The fitment parts and the silencer are first class as well.

[gdr8]

Thanks for the info on the pipe. I will have to stick with what I have for a while as $$$ are alittle tight right now but at least I now know what to look for.
I guess my biggest surprise is how close the power is to my 107cc WRH motor. But as everyone said the pipe makes all the differance, so when I do get a different one I will be able to see what the real differance is.