Ongoing saga of Roadrunner 300 vibration By new2scootn (Read 2,156 times)

[new2scootn]

I think maybe I spoke too soon about having 90 percent of the vibration out of my trike. Oh it's much better but still get some shakes around 60+. I took the front tires off the rims and scooped all that nasty pudding-like Ride-On tire sealer/balancer stuff out of the tires and then spin-balanced them. Both were out of balance. (I found out that I had put too much Ride-On in them and that too much can cause balance problems too). Rode her tonight and she's great up to almost 60 mph then still has some shakes in the front end. I am gonna put the recommended dose of 5 oz of Ride-On in each front tire in the hope it will smooth things out above 60. Just read the new comments from justincrediblem... you're lucky you spotted that rear tire wear before it blew out on you mid-ride--I'm sure that would ruin your day! You definitely shouldn't ride it until you get the new rear tire on. That rear tire must have really been out of balance to wear that badly on one side. And about the front end alignment... you definitely can't go just by the number of threads on the linkage. You need to take careful measurements (I used a straight edge along the outside edge of each front tire-once straight up and down and another front to back) from the top of each tire, as close as you can get to the bottom of each tire, and then again half way up front and back. All of these measurements should be dead on for best ride. I couldn't believe that mine was set right from the factory! Hope this helps ya get that thing back to smooth cruisin'.
Oh yeah, remember I mentioned how I lost power and had to pull to the side of the road? Well it has happened several more times and I now know that she's gettin' starved for fuel. It only happens on prolonged near full throttle. I put a new fuel filter in and filled the tank and on the first ride after it didn't happen. But it happened again tonight(not as bad though) and she's down to half a tank. So I'm thinking it's either an improperly set carburetor float and she's literally runnin' dry, or possibly a problem with the pick up in the fuel tank.(I'd love to see inside that tank to see just how and where the pick up is. It's strange to have the fuel line connection to the tank at the tallest highest point instead of the lowest point so there's got to be some kind of line or tube inside leading to the lowest point.) As I get less fuel in tank I'm hoping to be able to figure out which is the problem.(sure don't feel like removing the fuel tank OR the carb if I don't have to.) And speaking of fuel, now my fuel gauge is reading empty most of the time so I followed Alleyoops suggestions and checked the float but it wasn't filling with gas and sinking. I checked for voltage and resistance and both seemed good. So I banged on the dash near the fuel gauge and shook the trike side to side and low and behold the gauge started to work again. I tried wiggling wires and playing with connections but I couldn't get it NOT to work after that-figures! Oh well, a headache for another day!

[Alleyoop]

The fuel line on the tank is on the bottom and not on the top. The hose you see on the top is your TANK VENT. Now that goes to a Charcoal Canister which could be a problem. If it is not venting properly it will not allow sufficient fuel to flow out of the tank. What you can try is unhook that VENT HOSE from the canister and block the connector on the Canister. Then Put a Fuel Filter on the VENT HOSE coming from the top of the tank and tie it up high somewhere and see if that fixes the problem.
Alleyoop

[new2scootn]

Hey Alleyoop, thanks for the suggestion but that aint' no vent hose. On the Sunny the fuel line attaches at the top of the tank and goes directly into the vacuum fuel pump and then to the carb. I had her all torn down so it was easy to see. A guy I work with says he has a chinese atv with a similar set up and he had to replace the pick up inside the tank on his.

[Alleyoop]

WOW!! that is hard to believe are you sure about that. Can you take pictures of the tank area. I mean for it to suck up fuel up to the top of the tank and then down to the carb it has to have some suction. But if it is so then from what your saying the pickup must NOT be near the bottom of the tank inside so when it gets to a certain level it cannot suck up anymore gas.
Alleyoop

[new2scootn]

Here's pics of fuel tank and lines Alleyoop.

The blue arrow shows the fuel filler neck at the top of the tank. The red arrow shows where the fuel line attaches to the tank(hidden behind a bracket in this pic). The yelllow arrow shows the fuel line following along the fuel tank around to the other side to the fuel pump.

Here the arrow shows the vacuum fuel pump with the fuel line entering in the front, exiting in the rear, and going on to the carburetor.

And finally this one shows a view looking straight down from above the fuel filler neck-the arrow shows the nipple where the fuel line attaches(also shows where I had to put the epoxy to fix the pinhole fuel leak in that nipple).

[Alleyoop]

I wonder why they put the fuel line up high, you would think you would want the outlet to be at the lowest point in the tank. Maybe they are concerned that the crud that my peel off the tank will cause problems. But that should be taken care of with a good fuel filter. I can see problems with that kind of setup, one if the line does not go far down enough and another that it may for some reason bend and not draw fuel when low etcc.

So yes If it can be taken out and checked I would do that and then measure the length and see if it is reaching far down into the tank.
Alleyoop

[rapidjim]

This is the same system that Ice Bear uses on their 300s since 2010. I have not heard of fuel delivery issues, pump has t be strong enough to handle it. Older snow mobiles use the same system. If it was me I would have used an electric pump instead of vacuum pulse.

Think about an older car fuel tank, the fuel is sucked "up" through a tube and out the top of the tank. Newer cars use a fuel pump in the tank to push the fuel out. Neither system has the tube all the way in the bottom of the tank.

Jim

[justincrediblem]

My new rear tire arrived today. I will be getting it mounted and balanced tomorrow. I went ahead and had the front tires balanced yesterday. I found that my right front tire was mounted incorrectly. The rotation arrow was going in the wrong direction. So I had to have it taken off the rim and remounted. I'm hoping with all tires balanced and mounted in the correct direction I will have a much smoother ride. I'm hoping for no more wobble issues. Got my fingers crossed. The front tires look aligned and with a straight edge the left one is off just a very tiny bit but I think I will leave it be. I have been driving the trike awhile now
with the alignment off quite a bit but I don't see any visible wear on the front tires that show.

I also noticed my rear tire has a j on it. Everywhere I have seen on the internet a j speed rating is 63mph. The new tire I got is a shinko sr56

[justincrediblem]

Shinko sr568 130/60-13 rear tire with a p rating (93mph)

[justincrediblem]

The new rear tire does not hop like the original tire while the trike is on the center stand. The trike still has the violent wobble and is not drivable. I noticed I have a lot of play with one of my left front bushings. I am assuming that may be the cause now. The violent wobble did not start until I aligned the front tires. Maybe the alignment. Put more stress on the bad bushing. Whatever the issue I am very very dissapointed. This is twice now that the trike has been broke down and I just started driving it in early July.

[new2scootn]

Can you take a picture of the bushing you're talking about? I'm glad you found that the one tire was rolling in the wrong direction. I actually noticed it from looking at your pictures the other day but my lazy butt never made it back to let you know. I've got almost all major vibration licked on mine now. Balanced the front wheels and installed the PROPER amount of Ride On in the front tires and now when slight vibration starts up at about 62 mph if I maintain that speed it goes away in about a 1/4 mile(as the Ride On does it's magic) and then is smooth up to 74. My biggest problem now is sudden loss of power(running out of fuel) on prolonged hard acceleration. I know it's not losing spark and I suspect that the vacuum fuel pump just can't keep up at near full throttle. If you or anyone else have any ideas I am all ears. I am borrowing a video scope from a co-worker and will be looking inside the fuel tank this weekend. I'll let you know what I find.

[daddue11]

Hey fellow Roadrunners. The strangest thing happened to me today,I went on a aprox 70 mile ride on Liberty today and I thought the ride felt a little squishy in the corners. I was waiting for her to start shaking violently at around 51.5 mph but there was just a little shake at 48mph but then it would go away at 51mph and I could kick it up to as fast as I wanted without any shake. I have no Idea why it cleared up like that,I do know that it set for almost a month?? the only thing that was different about it was the squishier ride in the tight corners but it was not a nuisence. I did notice that when I checked the tire pressure after the ride that all of the tires were about 3 lbs low on tire pressure, I wondere if that dampened whatever was making the shake and also why it seemed a little squishy Don't know for sure, but whatever it was it made for a lot more pleasant ride except in the really tight corners where it seemed a little squishy.
I know this probably won't help y'all any,but I hope it does. Tommorow I'm gonna put the correct tire pressure and see how THAT changes the handling. ride safe my friends.

[justincrediblem]

Looking at it more this morning, I have a little movement with both right and left front bushings. The left front seems to have a little more play with it though. Here is the pic of the left front bushing I am suspecting may be the culprit. Notice the circled area is showing a space where there shouldn't be any space.

Attachments:

[Alleyoop]

Yep, any play there will cause a shimmy. Mike from Florida has a Trike and has a similiar problem but his of course is two tires on the rear. He is having a HOTROD shop rework them with good new bearings and good sleeves done. At least yours has the Grease fitting to grease it up. On the trikes they did not come with grease fittings so he is also having them done up with grease fittings to grease them up.

It could also be caused by a tire that has a high spot and when blown up to much then the high spot causes it to shimmy at certain speeds. So lowering the tire pressure would eliminate most of the high spot hitting the road.
Alleyoop

[justincrediblem]

Here are a couple of video links:

A video showing the movement in the bushings:



A video showing the wobble POV view (notice my handle bars bad shake):




I removed my fenders to see if one tire would shake more than the other but I could not tell of a difference. But as you can see from the video there is no way for me to operate the trike safely.