EFI Conversion 96 Royal Star

[winston66]

Winston66,

from down under in sunny Western Australia.

I have just gone around the block on my modified XVZ 1996 Royal Star (I recently converted it to a four wheeler ) whilst towing my newly constructed teardrop camper trailer the distance was about 144 miles.

When I checked the fuel consumption I was concerned that I had used approx 6 Us gal.

this gave me about 24 Mpg. Now I feel that that is not good, especially as our fuel price here is around USD, $6.00 a Us.gal.

So now I am contemplating a fairly ambitious modification IE. changing the Mikuni carb. set up to an EFI. set up. Hopefully in order to drastically reduce the fuel consumption which at the moment I feel is quite excessive

Now I know that this is a pretty radical thing to do.

But at the present time the RS. is running real well ,it starts on the first compression, idles and runs great, no flat spots or backfires and pulls like a train,With an awesome exhaust note from the four separate exhausts. I pulled the plugs today and they looked perfect.,no burning or oiling or discoloration and they were identical in colour etc so I am stumped as to why the hefty fuel usage .

My other mods so far have been to change the diff. to the V Max ratios ,Installed the Dyna 300 Ignition mod.presently on curve 4, I have today dropped it back to curve 3 .There is no dragging, from the brakes, and my speed was limited to a maximum of 60 Mph,(100) Kph. because of our road laws whilst towing.

I must admit that for part of the time There was a bit.of a head wind maybe 15 to 20 Mph.

Now my question is ,has anyone experimented with an EFI set up for these bikes, and or do you have any relevant knowledge that I might find relevant or useful,

I really don't want to attempt to reinvent the wheel ,so to speak.So is there some one out there that can pass on some gems of wisdom.

I do hope that some of you great bunch of guys can have some input and offer me some guidance in this idea of mine.

I will attempt to add some pictures to this post so that you all will can possibly get a better idea of where I am coming from, as well as what I am trying to do.

Cheers to all.

Winston 66 Western Australia

[Bubber]

I must be the first one up in the central time zone of the US.

 

I have heard of someone doing a FI but, if I remember reading it correctly it is a big, big, undertaking.

 

not sure all that it takes but there has to be a control, wire harness, the injectors, and I am sure much more.

 

First question: How would the injectors be mounted in the head? That may be the biggest and hardest one to solve.

 

Good luck with your project.

 

Bubber

[dacheedah]

http://www.roadstercycle.com/yamaha_vmax_fuel_injector_cv_car.htm

[djh3]

If a throttle body system was used you would probably have better chance. The TB would go in just where the carbs do. I would think there is probably a system out there. Heck just get a set up off a V-max with it.

[Ron Melby]

Dude, that trailer is big after you stretched it out (looks cool though). If you are towing it loaded or empty I would doubt going to a fuel injected engine is going to help much on the fuel mileage, I think you are asking too much of your bike, jmo. Good luck and be safe. Ron

[Huggy]

Going to be really heavy on the tongue of that trailer when loaded! I'd be moving those wheels closer to center!

 

[winston66]

Winston 66,

Hello everyone, Thank for the comments,

Firstly about the trailer,I got the idea from seeing picture of The Idaho Bedroll camper on u tube and this was my modified concept.

The idea is that it is towed only when the the two halves are pulled in together, the body then only measures 1150 mm. long, and the camping gear (esky,matress,sleeping bag , tools,spares,clothes etc, are packed inside,

Then when stopped the two halves are separated, (pulled apart) by extending the front ,(it slides forward up the draw bar, The body then measures 2400mm, long. and then there is no need to have to erect a tent because there is a full size bed with a good comfortable foam mattress the opened floor area measures 2050 by 1020 and then at the rear there is a separate storage area (galley) for the other small odd stuff.

The total weight with all supplies loaded up is just a shade under 200 Kg.which is quite easy to handle and this includes a full esky with ice and beer.

When towing with either of my two bikes it tracks beautifully and the extra weight on the towing bike is hardly noticeable .

One of my previous trips I covered 450 kilometers in six and a half hours including two 15 minute breaks .I was using the Honda ST 1300 as the ride that day

I arrived home feeling quite fresh and unstressed,

Incidentally the fuel used that day averaged out at 15 kilometers per liter. which is about an increase of another five kilometers per liter over what the Royal star uses ,

So perhaps this might explain somewhat the reasons why I am thinking about the EFI. mod for the Royal Star.

Please keep the comments coming.

Cheers to all,Winston 66, Western Australia

Edited August 7, 2013 by winston66
spelling

[skydoc_17]

Hey Winston,

Very nice looking rig you have there! You didn't mention if the ST1300 is a trike as well.

I would venture to say that the ST weighs in a few hundred pounds lighter. Which brings me to my point. With the added weight of the trike kit, and the weight of the trailer, you are putting a tremendous load on the engine in this bike. I have found that these bikes are more than up to the task of pulling this kind of weight, but the price you pay will be in gas mileage. Things I would try BEFORE I went the EFI route would be a pair of K&N Air Filters. I would also try staying out of 5th gear on anything other than a dead flat road.

I would also install a Tach. and keep this motor in the 4000 RPM range while cruising. If you are "lugging around" at 2800 RPM's in 5th gear, you're not using the "power band" of this motor properly. If I remember correctly, Even though the ST has a 5 speed tranny, this closer ratio, "SPORT touring transmission is definitely a plus when pulling the extra weight of a trailer. Keep in mind that your early model RSTD has the smaller Carb. Set on the engine. Instead of EFI, perhaps you should consider the 1999 up "Larger Carb. Set" upgrade. This upgrade is much more "doable" for the average person, and will net you another 15 to 20 HP easily.

Also, VMAX cams are an option as well. Keep in mind that the fuel delivery system is just that, the system that brings the fuel to the engine. The controlling factor for horse power is the volume of the cylinder heads, and the compression ratio of the pistons. This is like carrying 10 pounds of ice to a 5 pound ice chest, it's a waste of time, energy, and money! Comparing the RSTD to the ST is "apples to oranges" at best. I think that if you press on with a few of the mods I have mentioned above, and change your riding style a bit as far as RPM goes, you will be able to "squeak" ALL that the Yamaha RSTD can offer you. After that, it's like we say here in the US, "it is what it is".

Just my thoughts, for what they are worth.

Earl

[RandyR]

my miles per gallon go down noticeably when there's a headwind. Riding at 60mph with your rig, I'd keep it in 4th gear most of the time, even with the vmax rear gears.

 

Your rig is the trike, right? so is it an outrigger style trike that keeps the Yamaha rear end?

[winston66]

Winston 66,

Thanks for your comments Earl, This is the sort of feed back that I am after,

In the past I have studied Lynn Nichols write up of the 32 mm. cab. swap etc. I have even printed it out and I was seriously impressed with it and did consider doing it.

Unfortunately here in Australia getting a suitable set of carbs. would be impossible these machines are rare beasts here I dont think that I have seen any other Royal Stars let alone any late model Venturers.

Also because I am so isolated here in the country good technical and or mechanical help or back up for something like that is non exhistant.

I guess that could also be said for the proposed EFI conversion, except that every car these days has an efi set up and parts would be a lot easier and economical to source. There are plenty of small cars to choose from, and a CPU from a Holden(GM) V8 would be suitable as we can reprogramme it.

All that being said , if I could easily source the suitable set of carbs. that have been rebuilt and properly set up for the job, as well the other needed and necessary carburetor parts at a reasonable price I could go that way. I dont think that I would be interested in the cam and valve spring mods . I am not an aggressive rider and I dont think that the extra rev. range or higher cruising speed ability would be of use to me.

Thanks again for your comments.

Incidentally also thanks for sourcing the new clutch slave cylinder ,and the master rebuild kit .the are in and working great.

You will also remember supplying the replacement front discs and the R1 calipers etc.

Cheers Winston 66, Western Australia

[winston66]

my miles per gallon go down noticeably when there's a headwind. Riding at 60mph with your rig, I'd keep it in 4th gear most of the time, even with the vmax rear gears.

 

Your rig is the trike, right? so is it an outrigger style trike that keeps the Yamaha rear end?[Winston 66,

Yes Randy

/QUOTE] Thanks for the tip I will be trying that, and yes the trike is an outrigger style that just bolts on , we designed and I made it here I did not have to alter the RS in any way ,it used existing bolt hole attachment points and I did not even have to weld any brackets etc to the bike frame.

The outrigger design utilizes independent,trailing arm suspension with air over dampening,and incorporates an anti sway bar for stability whilst cornering.

The wheels are 15 inch X 7 Volvo /early GM stud pattern and uses 205X15 Perilli tires

with about 6 to 8 mm toe in each side.

The anti sway bar is tuned with different length linkages to keep everything level in order to compensate for the road camber and in straight line travel so that you dont have to fight it whilst travelling in a straight line on a cambered road.

The system works, and is easy to control, has great stability , is great when cornering does not need much musselling to get around but most importantly ,as it is regarded as an accessory, there was no need for a vehicle inspection or licencing change.

Cheers to all.

Winston66

[dacheedah]

Who makes that conversion?

 

 

 

Sent from my iPhone using Tapatalk

[PGunn]

I must be the first one up in the central time zone of the US.

 

I have heard of someone doing a FI but, if I remember reading it correctly it is a big, big, undertaking.

 

not sure all that it takes but there has to be a control, wire harness, the injectors, and I am sure much more.

 

First question: How would the injectors be mounted in the head? That may be the biggest and hardest one to solve.

 

Good luck with your project.

 

Bubber

 

I was working on a setup but it got to the point of being a lot of work and finding the right throttle bodies and getting them in a package that would fit was where I hit the wall. I now own a set off an R1 and a set off a Honda 800 (they are in a square package already but still need to be modified to fit. Next comes the computer to run the whole thing that in the 500.00 range....

[Pegasus1300]

Between the outrigger setup and the trailer I think that you are doing about as well as can be expected as far as your gas mileage is concerned. Trikes even outrigger types just do not do as well as single track vehicles. Factor in a stiff headwind, pulling a trailer, and probably running in 5th gear at 100kph and the gas mileage goes to pieces. I don't think you would improve the gas mileage enough to justify the work and expense. Now if its just something you want to do for the challenge hey go for it.

I know when I started pulling a trailer with my RSTD the mileage fell by 10% to 15%. and it was worse in a headwind. On my Gold Wing Trike the mileage also fell and rear tire pressure also makes a difference. Again as a trike it has a wider stance which presents more wind resistance which cuts down on mileage. Same story wider/more tires all add rolling resistance.

[winston66]

Winston 66, Western Australia.

well hello again everyone.

it has been great to see your comments and get the feedback, it certainly helps me to clarify my thoughts about this idea of mine.

Today I have ordered a stand alone automotive rev .counter as well as checking out the Venture Virtual Tach. Redlined and now I can see How running in fourth could help with getting into a better load range for the motor.

It will be most interesting to see how this exercise works out.

My rudimentary reckoning tells me that give or take a little bit that with the V Max gearing that at 4000 rpm my road speeds in the various gears would be something like this.

I have not taken into consideration any differences between the standard Royal Star gearing, And or what the Mk11 Venture has , I believe that there are some small and subtle differences between different models.

 

1 st 30 mph. 48 klm @ 4000 rpm.

2 nd 44 mph 71 klm.

3 rd. 63 mph 100 klm.

4 th. 77 mph. 123 klm.

5 th. 96 mph. 155 klm

 

It seem to me when looking at those figures that the poor old motor will still be struggling along even at 4 th. gear at 60 mph. or otherwise 100 klm. Per hour, when it will be doing something like about 3500 rpm.

I had noticed that before ,when the RS as still a two wheeler that it did not feel properly comfortable until the road speed was above 65 or 70 Mph. Then everything just seemed to smooth out.

Now after all that, I am even more interested in doing the 32 mm. carburetor swap that was mentioned by Skydoc 17 in a previous post.

I will just have to try and source the necessary parts which will be one heck of a job over here.

Well that's all for now folks, so until.

the next chapter, Cheers to all,

winston66

[hendersd]

http://www.roadstercycle.com/yamaha_vmax_fuel_injector_cv_car.htm may be interesting