Twin Engines

[SirJakesus]

I found with my new TLE43 the 30oz fuel tank and cap seal too tightly and it'll starve the engine of fuel. You have to back the fuel cap off a bit to let the engine suck more fuel. Check it out I bet you thats the problem

 

[5-7HEAVEN]

I'll try that, Jakesus. I emailed Dave Staton, and he said to verify gas/oil mix and stop switch. Of course I did that, so I'm waiting for his next response.

 

[SirJakesus]

Well if that doesnt work theres always the failsafe of cleaning the carb and fuel lines/filter with carb cleaner and cleaning out the air filter. I'm sure it's something small.

 

[5-7HEAVEN]

I'm hoping it is something minor; I'm awaiting Staton's response, as I don't want to troubleshoot too deeply and void my warranty. Both of my engines are identical, so it'd be easy to replace and test the carb, coil, etc.

 

[5-7HEAVEN]

Just as SirJakesus suspected, the problem was the gas cap. I let the engine sit for two days, then checked and found the gas cap to be VERY tight. After loosening and retightening, the engine started in three pulls. I drove the bike 5 miles to work, and with dual engines it shaved a few minutes off of how long it usually took with my single engine. It rained enroute, but the tires slipped once, whereas with single engine I would have to stab and release all along the wet road surface. Dual engines made a BIG difference in traction, even with one slick tire in front and a stock nubby rear tire.

No problems whatsoever, but I haven't revved the new engine too high, since it's breaking in. I didn't have a chance to floor the engines, since the roads were wet and traffic was very heavy. This long stretch of road that I usually let loose was choked with bumper-to-bumper traffic. It made me glad that I motorbiked to work.

 

[MotorBicycleRacing]

Photos?
Without pics I don't think anyone really believes you put 2 motors
on your bike
So how about some big glossy pics with close ups?

Great you got it running ok
How is using two throttle controls working out?

 

[5-7HEAVEN]

Well, I've never posted photos before. I'll try to figure out how.

One thumb throttle on each side, and I'm searching for optimum positioning. I noticed that it's better if both clutches are engaged to reduce friction drag from the rollers. Otherwise, the working engine needs to overpower the idling engine's spindle drag, which is substantial.

If the roads are dry after work, I'll motorbike the long way home and tackle the toughest hills, while trying not to overload the new engine .

Man, I miss my ROCKSHOX fork. The bike and I take a pounding without its shock absorption. Need to fab a U-shaped bracket for the suspension fork to accept the motor mount. I should also install a front disc brake for safety reasons. That will also eliminate the front v-brake, which is being smothered by the motor mount.

 

[ozzyu812]

Take pics with the camera on the lowest setting. Only 1.91 MB alowed in .jpg and .jpeg Cant wait to see it! Also top speed after break in.

 

[SirJakesus]

I was really confused by that myself 5-7. I thought the return line was supposed to keep the pressure normal in the tank. I'll have to keep an eye on it as I worry about it leaning out when that happens.
About the drag requiring both engines to be engaged at the same time... are matched rollers sounding like a better idea now?
I agree, we need pix! I've never seen a bike with two engines before unless it was electric gas hybrid.
If you come up with a fix for the fuel pressure problem let me know. I'm a bit hesitant about leaving the cap a bit loose for possible leakage problems but I don't want my engine starving for gas/oil either. My other mitsu doesn't have this problem but it also has a different, possibly better gas cap. I'd be a bit angry if I had to buy a replacement gas cap for a brand new engine. I think I'm going to become a thorn in statons side one of these days, first the kinked spoke thing now poor engine siphoning...

 

[5-7HEAVEN]

SirJakesus, I noticed that my old tank and cap are totally different from the new engine's, and it never had fuel problems. You let me know if you solve this problem and I'll keep you posted too. And no Sir, it's not the roller mismatch, because there is substantial friction loss even with the engines off but pushing against the tires. If I can minimize the friction losses, the bike will go even faster! To get rid of most of the drag, I could rig the front engine lift ala Dimension Edge, then convert the rear friction drive with my gear chain drive. Yeah, that'd do the trick, but I need to enjoy this brand new bike with twin engines first before disassembling it again.

Today I drove to work and it rained. I'm presuming that the twin engines offered excellent traction because very little throttle was needed for low-speed travel. Throttle positions slightly over clutch engagement would be sufficient for many riders. And because of low rpm and alternating engine usage, this combination offers excellent gas mileage. Surprisingly, I might be getting close to the same mpg as I did with the single engine.

So I go home to top off the fuel and ride farther. As usual, the bike's front wheel is up in a tree fork so I can fill the tanks closer to capacity. I just gotta install an extra remote tank.

Just like before, the new engine quit again, three miles from home. As I stopped and leaned the bike onto a signpost, I look down to see one of my 9/16" nuts on the ground! Double trouble! All but one of the rear motor mounting nuts had vibrated off in the 13-mile trip. My bad, because I probably didn't tighten them. So with two locknuts and zipties, I secured the rear engine. Then I loosened the gas cap, retightened it, pullstarted twice and the new engine came to life! It was getting dark and this was a sure sign to head home, and I was anxious to tackle the medium-sized hill near my place. I got a running start up the hill with both engines blazing, keeping up with traffic in the curb lane. As anticipated, the new engine's rpms were rising, so I released its throttle and used just the rear engine with 1.5" roller. The car in front of me slowed down halfway up the hill, so I braked and kept my distance. When he continued, I throttled both engines but not full-bore, keeping a safe distance from the slow-moving sedan. I'm guessing that the car was traveling maybe 25 mph, and I had to restrain the bike because it was charging like gangbusters up the hilltop!

That second engine is key to great performance. If I can lift the engine off the tire to eliminate friction drag, the bike should be even faster because it'll have less rolling resistance at the top end. When I feel the rear engine's rpm begin to drop, I just floor the front engine until the rear one picks up speed, then slack off the new engine. What an excellent way to add more power, if I say so myself.

Did I mention the sounds of twin engines idling at the stoplight?! Not too loud, but a freaking radical beat!