Messages

1

General Two Stroke Talk / Bike skipping up in revs???

« on: January 05, 2012, 04:53:19 PM »

Turn the air screw out a bit. Sounds like it's running lean to me.

2

General Two Stroke Talk / rm 125 piston size''''''''''''''''s

« on: December 10, 2011, 01:45:39 AM »

Wiseco 54 mm is correct. I have one in my rm. Runs very strong, and I am extremely happy with it.  

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 05, 2011, 11:30:10 AM »

Emissions should decrease about as much power increases with this setup.

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 05, 2011, 09:19:14 AM »

yes, you are right, i have no clue what i am talking about, and your f*cking ear is more accurate than a wideband o2 sensor.

you should market your services to various dynoshops.  ear-tuned.

get real.

Read reply #5. I totally agree that my ear can't compete with an o2 sensor. Never said it could. I said TBI FI was not going to cause noticeable improvements over a professionally tuned carburetor to most riders, but would lead to a small percentage of increased power because of the precision of FI. There are set formulas for finding the right jets for a carb. Once jetted, you have to set the float by ear if you don't have a dyno in your garage. With experience, you learn what to listen for. To fine tune the float position for maximum power, you ride the bike and observe the engine under load throughout the power band. Lean it out until it just starts to rev a little too fast and back off a little. Best power curve is there. FI is way more precise, but the difference cannot be felt by the average rider. The fuel atomization from the injector will be greatly improved over a carb and will cause a slight power increase, too. Jeremy, or whoever is riding this bike, may be able to feel the power increase because of the level of riding he does. I know, myself, that I have a greater room for improvement over my bike, so the extra power would really be of no practical use for me. It is only when the bike starts to have greater inefficiencies than the rider that something like this pays off.

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General Two Stroke Talk / Re: 2 vs 4

« on: October 03, 2011, 08:32:36 PM »

My YZ 250 does do pretty well against 450f's. 

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 03, 2011, 05:48:33 PM »

I do too, that's why I don't really like FI for the average bike. It's a good idea/investment when it's going on a high output race bike, but for the the 99% of us that don't ride a 2 minute 45 second lap at Steel City, the .25 to 1.75 hp difference is offset by rider error. I have nothing against jetting, just don't think its always necessary to get peak output. Don't get me wrong, my yz 250 is jetted, but the carb was set up before I bought it. It's a good addition to other upgrades, but not so much for a stocker. 

Nice RM by the way!

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 03, 2011, 04:21:16 PM »

i'm sorry, but this is just old school thinking.  no ones ear is better than an o2 sensor, i dont care who you are.  and there IS an absolute. its called stoich's ratio.  its 14.7:1.  the goal is to get as close to it as possible, from idle to redline, without detonation.  detonation can be avoided by either adding more fuel, or pulling out ignition advance.  end of story.  all of this nonsense about "hearing' and "smelling" how it is running is just that.. nonsense.

Maybe thats cause you can't do it, but it is done and very done well. I've never read plugs on a dirt bike engine, but I have on a few car engines to diagnose what is burning in the engine. You can tell a lot from reading plugs, but that has no performance reasoning. It gets you in the ballpark as far as rich/lean. Smelling exhaust can also be useful. It is used by mechanics to determine if something is not working correctly like, for example, an o2 sensor. From there, you listen, and it DOES work. Stoich's ratio is an absolute, yes, but it does not always get you the most power in the real world, especially with variables such as air temperature/density changes and octane rating.

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 01, 2011, 07:07:12 PM »

Not to sound like a dick, but watch american icon the hot rod, they did an episode that included fuel injection and the first time fuel injectuon was used was sometime in the 30s or 40s and was first used in stock car racing, the cars running it instantly gained 30HP and were setting track records

This was mechanical FI and it is used for decent gains at constant rpms. Like I said a little earlier, it runs rich at lower rpms and lean at high rpms. If you set the system for WOT, there's two settings, idle and WOT. Anywhere in between is way too rich and the engine looses power.

9

General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: October 01, 2011, 09:30:26 AM »

FI has made it easier for you to just get in your car and go, but it hasn't yielded much power increases. It helps reliability for the people that can't listen to an engine thats not starting and realize they may need to pull the choke out or pump the gas pedal. If there were substantial increases, all performance cars would run FI. In drag racing, the really fast cars run FI (top fuel, top alcohol, ect.) because they pump so much fuel/air into the engines, carburetors would limit the airflow and not allow the fuel delivery. Just to show how much fuel they pump into the 500 ci engines in top fuel, when the engines 'blow' a gasket and make that big fireball, it is because the engine hydro-locked from having so much fuel in the cylinders and blew out the 1/4 inch solid copper head gasket. I think they use about 16 gallons per 1000 ft. Carbs can't deliver that much fuel, but they can keep up with FI on engines with less demands. FI was not introduced for performance, it was introduced for many other reasons like to get people to go to the dealer to work on their cars, so your car can start easier in 20 degree weather, so there can be more electronics that costed less than mechanical equivalents because they were made overseas, ect. My 1974 Plymouth Duster does just as well as any other car, I just have to listen to it in different conditions and know how to adjust the carb on the performance engine in it. If the engine was stock, all I'd need was a choke and it'd be just as good as any other stock 360 ci engine with FI. Don't get me wrong, I'm happy to drive my FI Suburban around because of it's convenience. But it has 275 hp when the 454 Chevelle had 450 hp in the '70s with the 800 cfm carbureted LS6 454.

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General Two Stroke Talk / Re: New Idea for a Project but need help!

« on: September 30, 2011, 07:12:58 AM »

The best place to start on anything that you've never rebuilt before is a complete, assembled engine. Almost all you can mess up then if you pay attention to where parts go is putting the new piston ring in the wrong way when you slide the cylinder back over the piston. And if someone is selling a disassembled bike with all new parts that he didn't finish, 9 times out of 10, he found something wrong and doesn't want to deal with it. If he doesn't want to deal with it, often times, you won't want to either. Just something to keep in mind.

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: September 30, 2011, 06:14:47 AM »

Well then, I am surprised someone hasn't said it yet, but great job Charles!
I don't know whether these HGI kits are any good, if it is possible to get FI working on a performance 2 stroke or anything at all about the real world changes it will bring.
I'm very glad TSM is giving it a go though and very much looking forward to following the project with interest.

Would be fantastic to see some dyno graphs! of before and after.

Well said! TSM looks to be the leading innovator in 2 stroke motocross. Way to push ahead Charles!

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: September 30, 2011, 06:07:56 AM »

As for the lack of a battery, i think a lot of people would be surprised at what a capacitor can do. Ever wonder how an airbag can deploy when the car's battery is destroyed in a front end collision? There is no power coming from the battery to deploy the airbag. The computer has capacitors in it that store electricity for when there is none. Granted, it uses the electricity up very fast, but how fast does a two stroke engine rev? It doesn't take very long for the stator to come around again and recharge the capacitors. Theres no reason to have a chemical battery when power is constantly being made unless you can't kickstart your bike. EFI is simple to experts, just like carbs are simple to people that know what they are doing with them. Its more people in the dirt bike world that know how to fix or upgrade a carburetor than EFI, so its easier(and cheaper) for the small team or rider to use a carb because thats all they know and grew up with. This is a very big step in the right direction though, even if it may not be for everyone yet. If you oppose it, don't put it on your bike. But in order to get the emissions down, we have to stop putting a 40:1 oil ratio in our fuel. You can't change the oil ratio with a carb. This can be fixed with direct injection. This EFI system can change the oil ratio as needed to be efficient. Burn less oil, be more environmentally friendly.

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: September 29, 2011, 06:58:25 PM »

Yeah, but with experience you can adjust a carb by ear. You don't have to rejet a carb to tune it. Turn the float set screw. All you need is a small screw driver. That's easier than reprogramming an EFI system even if it only means plugging the laptop up for a few minutes. For a high performance bike, everything has to be right. If it is 85 degrees one day for practice, and it rains overnight and cools to 60 degrees for the race, that bike has to be richened up quite a bit to avoid burning through a piston. The pros reprogram their EFI before every race. There's no absolute air/fuel ratio. Just shared opinions on what's best. You have to know what you want as far as bike characteristics and test 'til you find it. Remember, this is not an out-of-the-box deal. It'll be interesting to see what happens. I'm pretty excited to see how she does!  

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General Two Stroke Talk / Re: HGT Fuel Injection kit on our YZ 144 Project.

« on: September 29, 2011, 11:51:17 AM »

Fuel pump is between the regulator and the zipties in the middle. I want to know if you'll have to reprogram it seasonally for the crazy temperature differences around here. A carb is petty easy to adjust, and four strokes usually run richer than they need to be with FI to be safe not to burn through a piston. Cuts down on power, but less failures for warranty to deal with. Two strokes like to have the mix pretty close to perfect for good response and top-end, especially on a smaller displacement. This all is fixed with more money/intelligence invested into the algorithms and quality software. So I'd like to hear about the company that manufactures the system, too. The power should be increased over a stock carb, but not too much of an increase vs. a professionally built carb because it is a tbi(the same principle as a carb). This is because of the precision involved with FI. Low end torque should only be effected by the CFM difference. Lower CFM means higher torque in the lower rpm range. High CFM gives the same amount of torque in a higher rpm. People that say it'll flatten out the power band may be pretty disappointed because those early FI tests that showed this were with Mechanical Fuel Injection. There is no change in the amount of fuel through the Rpm range with MFI so it runs rich at low rpms and lean at high rpms leading to a flat power band. I can't wait to see the results on the bike, though! Cool idea to try it on the 144 instead of the 296 (If i remember right) or a bigger bike. Hope it goes well!