In the last few days, I've been flooded with calls and e-mails asking about a multitude of things, but one common link has stood out. Dual Carbs.

While I know that dual 39's can reliese a ton of power from a built motor, the benifits from a mild motor are not yet measured. The other point that many of you seem to forget is, it's not exactly a bolt on. 2 serious points need to be addressed, frame clearance and exhaust clearance.

You will need to modify the frame to fit these carbs and allow the throttle cable a place to run. This may be easy for some of you, more dificult for others. Simply cutting away at the frame to make room would not be a great idea. Jeff did things the right way, and re-inforced for were he removed material.

Not all exhausts will fit with the carbs either. Some will fit with extremely close tollorance between the float bowl and the pipe, and others may not allow a fit at all. Be prepaired to modify or replace your current exhaust if things don't fit, or deal with the heat if the clearance is to tight. Boiled fuel doesn't run very well.

I am working on a solution to these problems, but it takes time. If your dead set on running dual carbs now, I just wanted folks to be prepaired. Jeff did a great job, and he made it look easy. Some of that was his skill, some of it was his resorces, and some was just luck. He has been extremely helpfull to several of you that are prepairing for this, but if you don't think you have all three [skill, resorces, and luck] of Jeffs atributes, you might want to hold off untill my project is ready.

I didn't post this for advertizing on my project, just as a warning to those of you looking at diving into this.

 

Knutz, is the thoery behind your air system to flow as much air as a Dual-carb set-up. Is it made for the 45mm or the stock 42mm?

Biggerisbetter.

 

Possibly more air than the dual carbs. There will be two options, more air and alot more air!

 

WHY would bmw run this setup if it were to big for there stock engines.
thats where i got my new system.and it's dual 40s ??????

 

AZSAND,
Dual 40mm's???!!!!!..........Man I am falling behind [img]i/expressions/face-icon-small-tongue.gif[/img]
Jeff

 

Azsand, any pics?

have you installed it yet?

Is this intake setup from the bmw? if so what was the price and where did you get it?

I am beginnning to think that the big hp hold up on these engines is the intake setup. I have heard some outrageous numbers from people using a stock bore with high comp piston, cams and dual intake setup.

Any more info would be great.

Bat

 

Bat, I think your head is going to explode! For every bit of info you get, it sparks 5 more questions. LOL A 5 page thread and now 3 more threads to help stear you in the right direction, and nobody realy has the definative answers that you hope for. Of those making claims of huge HP from stock bore and dual carbs, I wonder how many of them have ever actually put the bike on the dyno. The theory of, "he said he had 60HP, and I beat him, so I must have 65HP" doesn't really hold water in my opinion. I'm finding more and more that most claims are just that, claims, and they tend to be optomistic at best. Give me a call some time so I can answer your questions. I can answer 5 times as many questions, in half the time, if I don't have to type.[I'm not a good typist]

AZ, who said it would be too big for a stock motor? I simply said that I don't know what the gains are on a mild motor. Two smaller carbs would give better throttle responce[in theory] than one larger one, but would the improvement be worth the $800 or so, and the work needed to put this on a mild motor? I'm not sure, but I'm not saying it's not.

Jeff, do I hear dual 45"s in your future?

 

Knutz, I hear ya. I am skeptical of the claims I hear also. But I am just not sure what it is I want. Well, actually I know what I want. I want to be about 60-65 hp. I also want to be able to ride the bike. I don't want just a hillshooter. I want something that will run all day and ask for more. I am just not sure what the best route is, hence all the questions.

Have you ever dyno'd a quad with high comp piston, cams and different carb setups. I am looking for solid info on what can be expected.

I am guessing I am around 47hp right now. YOu had stated that the stock is 39-41 and with carb mount, cdi and exhaust that it would get about 7.5-8hp. So, to only get 50-55 with high comp piston, cams and carb swap it just seems like it should get more. I know more questions, but I want to do it right the first time and not have to buy this and then next month that is the hot ticket. If you see what I mean.

If going to the 12:1 piston is better for more power that is what I want to know, also if the hotter cams is better that is what I want to know also. No one seems to be able to say what the best setup is. Maybe there is not one best setup.

Sorry for all the questions, but this saves me on long distance phone calls.

Bat

 

Nobody has dyno tested every combination in the world. I have probobly done more than anyone, and I can't answer all your questions.

I'll knock $6[$.10 a minute for 60 minutes] off your bill[if you decide to purchase from me] to answer your questions on the phone. The time it takes me to type is worth ALOT more than that to me. I'm happy to offer free advice, but please work with me on this, 3 hours of typing[I type slowly] at $60 an hour, I'm out $180. LOL Not to mention it's time that I could be spending working on other folks motors or working on R&D. Answering your last e-mail took me about an hour.

 

knutz, sorry. I will call as soon as I am ready. I need to get all my questions together and all my thoughts, which is taking alot of time. I am sorry to tie you up answering questions on the net. I will call in a few days when I have all my questions ready.

Thanks for your time
Bat