Sprockets build: Drag scooter

wae stopped by for a bit a few days ago, and helped with the cooling system. I managed to make a bracket to hold up the coolant pressure cap. Still need to make one for the gas tank, and one for the coolant reservoir. I also discovered the vacuum petcock from the 250's gas tank was not going to work. Parts are on their way to switch it over to a manual valve. With any luck, I'll be able to get it together enough to fire up this weekend, so there can be some actual testing before loading it up and taking it to the Spring Nationals.

ITS ALIVE!! Sort of.

Video of the rear wheel spinning as it idles

Today, I finished making brackets, and riveted them into the bike's trunk:

Put together the fuel system:

Finished a bit of other work underneath, and mounted up the trunk. Not really any room to stash stuff anymore. It is now not coming off unless I remove everything in it first, since lines go through various holes in it:

The right side is extremely crowded. When some revisions get made, I'll try to move some things off to the left:

Once everything was assembled, I filled the cooling system with distilled water, in order to test for leaks. It held water fine, but due to the poor way I routed the hoses, it took forever to fill. I'll drain and fill it with coolant mix before long.

Ran into trouble starting it. It appears the Elite E's starter switch just grounds out when pressed, whereas the 250 switch actually had power running through it. Took a while to figure it out, but if I jump one of the relay/solenoid wires to the battery, I'm able to start it up. I'll probably clip the ground wire at the starter switch, and wire it to switched 12 volt. Since it appears to only be the signal for the starter relay, it shouldn't have much juice running through it.

Other issues:

-The bike slowly began to heat up, then very rapidly spiked. I think its a combination of the poorly routed cooling hoses, and the chance of air bubbles in the cooling system. I did not run it with the cap off, so I suspect there are still some trapped bubbles in the system. I hope bleeding it will help keep the temps down. It doesn't need to run for long periods at a time, but I'd prefer it to not get too hot too fast. Worst case, I might need to move the radiator so the hose runs will have more gradual turns. I'd rather not, though, since that would put it out in the open.

-The vent tube for the gas tank likes to spit fuel out. I think its a combination of vapor pressure (it was getting warmer when I tested the bike), and capillary action. I think I'll block the tube off, and drill a small hole in the gas cap for pressure relief. There is a slim chance one of the fuel connections is leaking, but the only one I couldn't observe directly was a 3/16" line on a 1/4" filter connection, so I'm pretty sure its just the vent tube.

-Found a nut underneath the bike after firing it up. Not sure if it was loose and sitting somewhere on the frame, or if something came unbolted. As it is, it vibrates quite a bit if you rev it, so I need to go through and make sure everything is snugged up.

-Still need to put some nuts on some of the engine mount and rear suspension link bolts. Not a big deal right now, but will be when its time for a test ride.

-The side panels need to be cut to fit around the frame brace.

In case I don't get this all done, tomorrow evening is going to be dedicated changing the oil in the Buddy 125, and doing anything else needed to wake it up from its winter slumber. That way, it can be used for the Nationals if the monstrosity isn't ready.

...and now it doesn't run.

Modified the bodywork to fit, fixed the starter switch, and ran the bike to bleed the cooling system. At one point it puked a bit, and spilled some water. After that, I could not get it to start consistently, even though, as far as I could tell, only some wiring got a little wet, neither the CDI, the voltage regulator, the starter solenoid, or starter got wet. Eventually, it wouldn't start at all, and the repaired starter switch didn't seem to be able to trigger the solenoid, so I had to jump it to the battery again.

I'm letting everything dry out today, just in case, but I'm not sure thats the issue, there may be several problems together, and I don't know the cause for certain. The engine is getting spark, based on the tach signal. I pulled the spark plug, and it was wet with fuel, so it seems as if it might have gotten flooded, but I swapped to a new plug, and no luck. Is it possible for there to be too little fuel for ignition, and have that cause a wet plug? I'm just curious if my next step should be to pull the carb and clean the jets, or if there's something else simpler to do first. This is all assuming it doesn't work fine tonight when I try again, I guess.

Love how you have the under-seat area arranged!

That's kind of strange about the thing dying out on you... I'd almost lean toward maybe the engine not actually getting spark or not getting a good spark? I don't know where the tach signal comes from, but it could think it's sending spark but a ground could have gotten knocked loose or something could have gotten wet? If it doesn't fire up tonight after drying out a bit, I'd do the old pull the plug out, ground it, and see what the actual spark looks like.

Tach signal is coming from a signal wire wrapped around the spark plug wire, so the coil is definitely sending a jolt to the spark plug. Whether its enough could be debatable. I ran the starter so much, I was rotating between batteries last night, charging one while trying to start the bike with another.

If I can get over this, all I really need to do is tighten up a few nuts and bolts, install some bodywork, and take it for a test ride. I do want to make a small airdam for the radiator to direct some air to it while its moving.

I really hope this is a temporary hickup. I'm worried about the possibility of broken piston rings, or a blown head gasket, or something else like that. At least the Buddy 125 seems to be good to go, so I may just be taking the mirrors, windshield, and top box off it, and hauling it to NC.

X2 on checking the spark strength.

Will have to check that. The fresh plug did end up with some black on it, so I assume it is sparking and burning some fuel. I'd think if the timing was off, it'd be backfiring, so I'm beginning to wonder about fuel again.

Going to guess its the fuel system. Filled up the gas tank, pulled the line at the carb, and opened the valve. Nothing happened. My theory is the combination of narrow fuel lines, and a filter designed for a tractor with a pump, and the various bends in the line trapped some air, and the fuel didn't have enough mass behind it to push through. Once I pulled everything and the fuel line was straight down, it was able to work. I think I'll pick up another valve while I'm out tonight just in case, and switch to a screen filter, and see if that fixes things.

That's good news! Should be easy enough to straighten out (so to speak!)

New valve and a screen filter installed. Bike fired right up, and ran right until the pickup in the tank became uncovered. I'm going to have to be careful with this at the track. One tankful might not last a whole day.

On another positive note, the temp gauge took about 6 minutes to climb from 100 to 160 degrees, so I'm guessing the air has been purged from the cooling system. Of course, the water will have to be drained so I can put regular Honda coolant into it.

Tomorrow, I'll put together a starter switch that runs right off the battery, tighten everything up, and put on enough bodywork to take it for a ride through the neighborhood. If that goes well, I'll rig up the license plate onto it somehow, and take it out on the two lane country road nearby for some quick acceleration tests

DAYUM!

Even just riding it in the neighborhood at 25-30 MPH is an experience. If it fails as a drag bike, I'm converting it into a street custom. Vibrates like a mofo, not surprising with a relatively solid engine mount, and a hardtail rear suspension. But, the acceleration is amazing. Something this small should not be this fast.

I'm keeping the clutch set up the way it is for the first two events. I may be giving up .5-1 sec in the 1/8 mile, but I need to get used to how much faster this is than other scooters I've ridden, not too mention, the first time I punched it, I almost fell off the seat. Which takes me to another issue - I am very glad I haven't reupholstered the seat yet. I think I'll carve the foam to add a bit of a lip at the back of the seat to help hold me in place.

The starter is still balky, I have a suspicion the solenoid/relay is dying. Since its a separate piece, I may just see if an old Ford one will work, since it'll probably be cheaper and easier to find.

Still tons of other little things to do. Tomorrow morning, I will take it out on a faster road for some quick tests. If all is well, then I'll start wrapping up all the other things that need to be done, and start working on how its going to be loaded, secured, and unloaded from the minivan.

Quick pic with the Abarth:

Took it for a spin this morning, after a delay due to the starter issues (more on that in a bit). Once I was on the main road, I hit the throttle hard, and was rewarded with a surge of power, then backfire and stumble, then power, etc. I had rejetted the carb in anticipation of the extra air it would get from the open intake, and since they are supposedly a little lean from the factory. I left the new pilot jet in, but swapped back to the stock main jet. Fortunately, the way the bike is set up, rejetting can be done with the carb still installed.

I pulled the start solenoid, and hooked it up to a battery, assuming it was dying. Worked fine. So, the next two possibilities were bad wiring in the harness (specifically ground wires), or bad connections. Since the harness is 29 years old, and I'm feeling a little lazy, I sprayed some contact cleaner on the connectors, wiped them down and let it evaporate. Started great, so I switch back to the original starter switch, and it worked, too. Yay!

In the meantime, I did a little bit of fiddly things, like setting up a spring up to strengthen the throttle return, and routing a few hoses and wires.

Took the bike back out, and no backfiring, runs great. And I ran it out of gas about 7-8 houses away from mine, and had to coast home. Going to have to keep a close eye on fuel at the races, that tank goes empty fast.

Once I was sure it ran alright, it was time to get it all together. There are a lot of hacks and details I will be fixing during the season, but here it is in "complete" form for now:

I love how unassuming it looks. Is it just an optical illusion, or is the radiator very nearly scraping the ground there?

It is close, just a smidge over 2" of ground clearance. It may be the first thing to scrape in a hard turn, but then if I have to lean it that much, things have already gone very wrong

Yeah, from the correct angle, it does look pretty mild, which is nice. Of course, a shot from the side does a good job of showing the stretch and the brace. I think having the gas tank under the seat helps, too. If I'd had to go with the tank on the frame brace, people might start wondering why it needs to be there, and what's taking up all the space under the body panels.

is there a class for mini bikes as well?

EvanB wrote: is there a class for mini bikes as well?

Not in the Spring Nationals / Twist and Gone classes, they are listed at the bottom of this page: http://usascooterracing.com/?page_id=1610

However, the regular season is bracket racing, and there is no separate classing then, if you email the organizer, he should be able to let you know. I know the track has allowed ATVs to race before, so I suspect mini bikes aren't a stretch.

Good: Spring Nats is this weekend!

Bad: One of the racers just lost his ride (another racer who just injured himself).

Looks like I'm going to be reconfiguring the van at the last minute for two bikes instead of one, and driving west a bit before turning east.

And panic averted. They found a closer ride.

I was really hoping to see how you'd manage to get two guys, two scoots, and all your stuff in that van!

In reply to wae:

Believe it or not, I have a plan

It involved building a couple of pallets that the scooters can be tied down to, then slid up into the back of the van. Was going to do it sometime anyway, but this would have just forced me to throw it a ll together quickly without a chance for refining the plan. With an approximately 4x8 space in the back, one scoot could be loaded forwards, and the other backwards, in order to keep their handlebars from getting in the way.

Back from Spring Nationals. I'll upload pics in the next day or so. Despite not winning any trophies, I had a lot of fun, and made it four rounds into the bracket race, which I think was the semi-final round. I'll need to wait and see the full results to be sure of it, things were a little hectic at that point.

The bike ran pretty well all weekend, though there is quite a bit of variability in its performance, depending on it's temperature. My best run of the day was in the first round (and my only round) in the King of the Hill. Up against a nitrous-equipped bike, I pulled off a 10.962 at 58.696 MPH. So, I shaved about a second off the best time the big bike ran last fall.

All the practice was good. I am going to need to order some parts and do some CVT tuning. Turns out my max rpm was about 1200-1300 below where the engine makes its peak power, so I wouldn't be surprised if I was leaving 2-3 HP on the table.

Next weekend is the first round of the regular season at Brown County. Hopefully, I'll have time to do a little work before then.

Picture time!

This was at the entrance to the track:

Shadyside was very much an old school drag strip, but a little more modern than Brown County:

There was a small custom show:

Some vintage racers:

And we even had a small fire:

Here's the full album.

Very cool!

Video of the scoot running up and down the street, race the abarth

Thanks, I do have a couple of videos of practice runs, but I need to do some editing before I upload them. Turns out the GoPro was still set up for in car, and the videos came out upside down. One of them show me getting schooled by an electric-converted scooter that was the fastest scooter there all weekend.

Oh, and the Abarth would demolish this thing in a drag race