750 Maxim Project

I thought I would share my project pictures, it is finally a roller. I bought the kit that was posted up around here from the virago site to put a rear wheel on front. Recently re wired completely, re jetted, and new tapered neck bearings from chacal, those babies are so nice, no more center detent! Thanks for a great site, much of my work would have been difficult if not for all of the collected knowledge.

 

Everything's looking GOOD! How do you like the sound of your pipes? Like the seat, what did you make the pan out of? Can't see because of the angle, is the front of the seat same width as rear of tank or what? Keep the pics coming...

skillet

 

Thanks, the pan is 18 ga. steel with a lip bent down on each side I used a stretcher on to give it the curve. Its as wide up front as the tank and narrows up at the end. Ill get pics up later today prob. The pipes sound good screams like a banshee, but idles quiet, you can see the 3 weld spots on the pipes thats where the baffle is.

 

Sweet, tel;l me more about the fro/rear wheel kit, i have a spare set of rims, what else do i need

 

Bad ass looking !!!!!!!!!!!!

 

Here's a couple more, the wiring, still needs to be taped up, and another angle of the seat

 

Thanks FAB

 

Like I said, looking good! Even with the baffle, it's still LOUD hunh? How's she running?

skillet

 

Lookin good StreetB. By the way how did the front look with the big tire and stock fender on? Sit too high or was it about the same?

 

I always like the fat front tire/wheel look without the fender on. I'm thinking of going with a fatter front tire on mine when I change it and take the fender off. Just makes it look meaner I think.

 

Someone help me with how to get a fat rear tire on the front. Looks like this still has the hub from the rear on one side. Is there a write up on how to convert one into a front?? I think it looks bad a*s too! Thanks!

 

It's a virago rear wheel with some machining done to it. A guy had a post on it in a virago forum but I haven't been able to find it again. I think he was doing peoples wheel for around 125.00 which included the hubcover. I even looked on ebay to see if he was selling kits but no luck.

 

Skillet, its running pretty good I think it is rich at idle, but I have yet to sync the carbs and mess with the mixtures. Ya it is still plenty loud with my baffles, I tried not to make it super quiet.

Seaguy, I tried the front fender but no way will it even go over the tire, I kinda think a small fender would look good on it, but I am not gonna mess with that now, gotta get er going good. Also it is actually a maxim rear wheel, BUT if I did it again I would have gotten a virago bucause the brake area is larger on the maxim wheel.

Kcoop, I got the kit, bearings, instructions and everything from a guy over in Mich. his name is Matt his e-mail is racer6692 @ yahoo.com he was only making a limited number of kits, but with interest he said he would put together more.

 

http://viragotechforum.com/phpBB/viewto ... &&start=40

This should get you to the virago site

 

I am jealous of the side covers. Looks awesome for sure.

 

Heres an update. New PVC intake to replace the pods, need to tune it yet.

 

Dude you're crazy. I like you!

 

Did you consider a 1 into 2 intake?
Balanced look + might be easer to tune.

albran

 

No I didn't, I only had one air filter. I like the way it looks, and as far as tuning I had re-jetted and started fiddling to get it right for pods, then decided to make this intake, originally planned for my stocker to delete the airbox, but decided against. It runs rich and loads up until you open the throttle. I am 3 turns out on the pilots all the way across, with stock pilot jets, I ran out of time before I could turn the screws down. What is everyone's opinions on the richness, will I be able to tune it leaner with screws?

Thanks hucker! You don't have to be crazy, but it helps.

 

I love custom airbox's!!! way more "origional" and maybe easier than pods... You're going to paint that pvc, righte?

 

I thought about making a simular intake but add adustable baffles to dial in the right amount of restriction.

 

Yep, it is going to be gloss black, I was just wanting to see if it ran different, and thought it was time for a photo oportunity...I think there is plenty of restriction not as much as factory but definitely more than pods.

 

Now that's one individually cool looking ride!

 

Looks good Street!!! Did you fab that exhaust yourself? It would be great if you could give more detail on it.... Good work!!

 

Hey Streetbrawler, Love that intake idea. Hey, I moved my ignition switch there (hmmm, we think alike!!)
My idea was to incorperate the filter in the middle of the PVC tubes, (where the air box used to be) so it would be more balanced for the carbs (just me thinking again) It just looks to me like with your setup, the furtherst carb from the filter would be starving for more air than the closest one? ( I could be wrong, just asking)
Did you ever manage to get it dialed in yet? If so, do a write up on what jets your using and the air screws turns would be nice. Just sayin'. PD

PS: Can't wait to see it this summer.

 

Thanks guys, I made the exhaust out of an old mac 4-1, I cut the pipes and turned them so they went equal down and under and into 2 then hooked them up into 2 1/2 inch exhaust pipe with a small baffle. I didn't take any pictures when I built it, DOH. I wish I would have.
Hey PD I thought of that same idea with my intake underneath would have liked it there but this was an after thought and my battery is smack dab in the way to go under, I am hoping to play with tuning it this afternoon, I figured the carbs should be able to get the air they need and just adjust it accordingly, looking at intake manifolds on 4 cylinder engines they are similar in design, so I thought I could get away with it. I will definately share my learnings, and short comings once it is dialed in! I am so ready to get it done! Spring fever is hitting hard!

 

Well I got it to idle, I have to blame the valve shims. Changed all 8, and re synched on the bench, then vac synch and only the #4 needed tweaking. I was impressed with the extra little growl out the pipes. Bad thing is I rode it out to my folks, about a mile and the clutch was slipping bad, got there and notice gas spewing from the crank vent. I really hope my rings are ok. The needles and seats were brand new. The carbs were off the bike the last 3 days the only thing I can think of is the needles haven't had time to seat yet and stuck open when I put it back together today. Now I have to change the oil yet again. It was a brand new filter and oil in Feb.

 

I really like what you did with the seat and rear fender. I am just curious, it looks like you have a shut off valve in your fuel line. Why is that?

 

Haha...didn't you read his post above? It's probably because he doesn't trust the petcock.

streetbrawler750 I took my carbs off for some "extra" cleaning recently, not touching the floats and got gas leaking out only one carb. turns out the tip of the wire on the float needle caught onto the float tang holding it open. Could be something obvious like that. Set them up and recheck the float height to pinpoint the offending one.

 

Ya the petcock has been modified to eliminate vacuum flapper, the petcock was bad when I got the bike because PO put the shut off on it. Manbot, it is wierd that when I have the carbs off and spill some gas out of them so the floats open(I assume), when I turn the gas on with the pvc intake off I can see the carbs draining fuel out of random carbs all sometimes sometime 1 or 2 or 3, but I just tap them and they seat fine. Is this something that is common? I write it off to new rubber tits finding where they need to be, and hope they will become comfortable over time and seat properly off the bat. I didn't notice the gas leaking this time I suppose because I had the pvc intake on it.

 

Beware!

Some aftermarket Float Seats need Polishing.
Some aftermarket Float Needles need Inspecting.

The Wire which fits over the Float Tang may cause the Needle to TILT ... as if the Geometry was off. They're made for "Slim" Float Tangs ... NOT Wide Ones.

Flipping the Wire around 180* Centers it.

 

Ok, thanks rick, I appreciate it. I was going to take them off again soon, I was going to make sure the floats didn't get bent out somehow and hung up on the bowls. I will definately check that. Heres a couple of shots of my 15 dollar headlight fairing from the swap last weekend. I am still messing with the synch. Have a 4 gauge set, I need to make a yics tool if anyone has a link I would appreciate it. Did a 10 mile test run with it and all but #4 plug was nice and tan like a paper bag, #4 was a bit wet but that is the offending carb to get synched up.

 

that is one of the sweetest soft-tails i've seen in a long time

 

Thanks plumber

I am having a hard time getting the carbs perfectly synched, I found plans for the yics tool and am going to be making one. The carbs are close but the rpms hang a little bit still when revved. Also when I decelerate and shfit down I get some small pops out of the right pipe. I checked for leaks with carb cleaner when it was running so I think the intake boots are ok. But I need to check the exhaust gaskets, I think that would cause it, any other ideas.

 

i think you should look at the air distribution from your manifold, maybe consider splitting it and using two pods

 

Well....plugs 1,2,3 are perfect color and 4 is a bit wet and grayish, I think there would be more problems from feeding the carbs seperate from each other than all together no matter where the intake is actually located, the carbs are gonna take the air they need no matter where the hole they are getting it from's locale. My wifes honda civic is an example, as is most 4 cyclinder cars, the air intake is on one side and feeds across. I don't think the manifold I am using is a problem. It has got to be an air leak that I haven't found somewhere.

 

I LOVE this bike. I need to get a seat like that. Any tips on how to do it? I don't have a stretcher or any special tools to make the pan. I think I'm screwed. Maybe I can con a fellow member into making one for me :lol: How long are those shocks and where did you get them.

GREAT bike!

 

Thanks koolaid

They are 10 inches long for a chinese atv, I got them from ebay, 25 bucks for the pair, they are very nice a bit stiff but have a dampner on them, they are not cheaply built. Neopreme bushings, I am happy with them. Umm as far as the seat I have been known to accept cash for labor. I think I could manage replicating it. You would need to weld the mounts on the bike yourself.

I am getting a bit frustrated in finding my air leak. Throttle shaft seal checks out ok, I guess I will order some gaskets for the header. And a colortune maybe.

 

I was thinking of going with something like this....

http://cgi.ebay.com/ebaymotors/Sportste ... ccessories

I'm not sure if they'll fit or not, but was going to get them and try them out, but maybe I'll have to rethink that and go with some shorter shocks.

PM me and let me know how much the seat would cost.

 

Hey, can you take a pic or two of you sitting on your bike? I want to see the riding position with the forward controls, the nifty seat, and the lowered arse...

Thanks

 

Well I don't know how or why but I guess persistance pays off. I just kept trying and it seems to idle and rev ok. I messed with my pilot mixtures and it seems to load up a bit, it is a pain taking the seat on and off everytime to adjust slightly. Oh well thats what has to be done. My popping from the exhaust I guess was a lean condition? Seems to be gone now. The bike seems to cut out a bit at high rpms, I have the smaller stage 3 dyno jets in now gonna step up to the bigger see if it helps.

 

The Pilot Mixture is regulated by AIR.
The AIR allowed to be pulled into the Cylinder "Picks-up and brings-along" Fuel from the Pilot FUEL Jet.

Increasing the Size of the Pilot FUEL Jet won't have the complete effect of adding Enrichment to a Critically LEAN Engine without Increasing the Size of the Pilot AIR Jet, too.

You need an increased AIR Flow to pull-up FUEL from the Pilot FUEL Jet's Supply.

The MAIN AIR Supply is exactly the SAME.
Shimming Needles and Increasing Main FUEL Jet Size to help alleviate running Lean also needs Increasing the Main AIR Flow to the Emulsion Tube.

The Problem which arises for getting enough FUEL to an Engine with Air Pods is:

The supply for Main AIR is regulated by the Main AIR Jet ... and ... The --> Maximum Amount of AIR allowed to be drawn to the Emulsion Tubes surrounding cavity by the INSIDE DIAMETER of the Main AIR Passage.

To satisfy the NEED for more FUEL for Top-End Performance it may be necessary to remove the Main Air Passages External Plugs and INCREASE the Diameter of the Main AIR Passages along with Incrementally INCREASING the AIR PORTS drilled in the Emulsion Tube to Increase the amount of FUEL Flow at Wide Open Throttle Conditions.

Until such time as someone solves the Pilot AIR and Main AIR capability; fumbling-around changing FUEL Jets up and down ain't going to get the job done.

 

wwwwwwhhhhhhhhhooooooooooooosssssssshhhhhhhhh.........

What the hell was that that just went flying over my head???

 

Thank you rick I really appreciate your help. I am going to have to study your recommendations to fully understand, it is a lot to take in right now. The plugs read a dark tan/brown when I pull them after idleing a while. When I drive it normal and just up to speed no hot rodding and come back the plugs are a nice even tan. I have not done plug chops yet I plan to, I have shimmed the needles up a click (dynojet adjustable) It pulls with power from low rpm no bog or cut out even if I should shift down to get power but don't it pulls up smooth. I think maybe I will do a plug chop tomorrow at the point where it cuts out to see what they look like.

I have drilled the diaphram piston as per dynojet recommendation with supplied bit, this would allow faster needle rise and air intake? Where are the external plugs for the air passages located, would that be figure 7.10b on page 124 of the haynes manual? air compensator jet it says on the air intake side of the carb.

 

the emulsion tube is referred to as a needle jet (main nozzle) in the haynes manual? The piece that the needle goes up and down in basically

 

Hey Rick I just had a revelation about the whole carb air/fuel passages/jets. I always thought that the stoichiometric fuel/air ratio came from the air drawing up enough fuel from the venturi to make the proper mix. That would be too easy. I followed what you say, and looking at the diagram I finally get that the Main Air and Pilot Air go through the Main and Pilot passages, and pick up air due to the venturi effect. This fuel/air ratio is MUCH higher than stoichiometric, and *should* reach a stoichiometric ratio when mixed with the air in the venturi.

I offer this hypothesis for why pods cause problems:
The slide and diaphragm in the venturi are supposed to make keep the velocity in the venturi constant (i.e. CV). Simple fluid dynamics here...if the mass flow of a fluid (air) increases through a tube with a constant area, conservation of mass dictates that the velocity must increase proportionally. The CV nature of the carbs allow them to conserve mass flow by increasing the area of the venturi proportionally with the increase in mass flow to keep the velocity *relatively* constant. So why does an increase in mass flow cause lean issues? I propose that the increase in mass flow will open up the slide too quickly, pegging it to the top of the carb, when the butterfly valves are not fully open. Opening up the butterflies further then increases the mass flow further and therefore increases the velocity proportionally - rendering the "CV" portion of the carbs ineffective.

Just as Rick points out, the air flowing through the main air jet, though passages, through the holes (14 on mine) of the emulsion tube is getting pulled by the "constant" velocity in the venturi (due to the venturi effect of course). That same effect is what causes the negative pressure in the emulsion tube to "pick up" the fuel. However there is a limit to the speed that air can flow through a certain area hole, and that is dictated by the speed of sound. You cannot get air to move faster than Mach 1.

So with the throttle full open, the slide is pegged, the velocity in the venturi is higher than it's supposed to be, and the smallest holes in the main air passages restrict the air flow that is supposed to draw up the fuel. I propose that the "choke" point would be the emulsion tube, as those holes seem smaller than any other in the system (even if you sum them). Whatever the choke point is...it's area would have to be enlarged...but you'd still have a non-CV situation. Perhaps if the spring in the slide were stiffer, or the slide was heavier, or the holes "transmitting" the vacuum to the top of the slide were smaller...anything to keep the slide from opening too quickly (*edit* - opening the slide slower would increase the velocity). If only there were some way to test this.....Again this is all my hypothesis...and maybe it should be in a new thread.

 

Well yay or nay rick? BTW I put the larger jet in and it might of helped but as you said didn't fix it.

 

I've had my say about this more than a few times, in the past, ...

Search:

Turbulence, CFM, Velocity Stacks, ... and you'll get my take on trying to make Pods work.

Essentially, and with my tongue planted firmly against my cheek, I see this discussion as a work in progress. The discussion started sometime in the early 1980's and continues, now, going-on 30-odd years.

All things considered; it boils down to: "Pods or Airbox"???

I pick: Airbox.

 

but pods look sexier.... that's the most important quality of our bikes, right?

 

I meant about what manbot said. I have that pvc intake on there. So it should get restriction, I have read most of posts and never heard you say aboout the slide pegging to the top.