My push trailer build

It seems a shame you may have to rebuild the hitch with heavier tubing. Do you mean the hitch or the whole tongue? Is the flex torsional (engine flopping side to side) or is it bending of the tongue like an archery bow? Maybe the flex is confined to the 90 degree joint where the tongue meets the trailer in front of the engine. If so maybe you only need a gusset there. Maybe the flex is actually due to the accumulated clearances in the hinge bolt holes. I hate to see these things built too heavy. Can you provide more details about this problem?
It looks like you may be able to remove the pull start housing and reattach it 90 or 180 degrees rotated so you can pull it easier when standing next to the bike with your other hand on the throttle. I used to park mine with the trailer at a right angle to the bike. It was stabler and also easier to start without tipping the bike over.
Maybe you could temporarily immobilize the throttle at halfway by tying a strip of inner tube rubber on the handlebar next to and rubbing against the rotating part of the twist grip. That works well for me as a cruise control for my motorcycle.
 
You don't need 2 in. tubing. I would use a minimum of 14 gauge Tubing, .080. Most tubing from the yard is 16gauge, .060. Try to mount the arm with less of a 90 degree to the trailer or gusset the arm on the trailer and gusset the bottom of where you connect the miter cuts in the arm. Also, if you redo the arm over again, better to run it rotated at 45degrees, like diamond shaped. Try grabbing a 10 stick of tubing and put one end on the ground then push pull down on it to see how much it flexes. Now rotate it 45degrees and do the same. You will see the flex is much less. It will be stronger this way with less flex. Thats how i have mine but mine is radiused. The main part is to not have so much of a 90 degree at the connection to the trailer.

Heres a sketchy sketch.
 

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It seems a shame you may have to rebuild the hitch with heavier tubing. Do you mean the hitch or the whole tongue? Is the flex torsional (engine flopping side to side) or is it bending of the tongue like an archery bow? Maybe the flex is confined to the 90 degree joint where the tongue meets the trailer in front of the engine. If so maybe you only need a gusset there. Maybe the flex is actually due to the accumulated clearances in the hinge bolt holes. I hate to see these things built too heavy. Can you provide more details about this problem?
It looks like you may be able to remove the pull start housing and reattach it 90 or 180 degrees rotated so you can pull it easier when standing next to the bike with your other hand on the throttle. I used to park mine with the trailer at a right angle to the bike. It was stabler and also easier to start without tipping the bike over.
Maybe you could temporarily immobilize the throttle at halfway by tying a strip of inner tube rubber on the handlebar next to and rubbing against the rotating part of the twist grip. That works well for me as a cruise control for my motorcycle.

Rotating the pull assembly sounds good and will help. I put the hitch on error. The hitch is probably the strongest part of the build. While it do have less than 1/16" play in the vertical and horizontal slide, it has Zero rotational play. That caused my previous hitch to wobble like no other.

The problem is that with moderate and heavy acceleration, there is a jerking feeling. Not a smooth acceleration unless I feather it until I get to above 25 and then it is smooth from there. I don't always want to go that fast though. That is the reason why I thought that the arm flexing has to be the cause of this acceleration issue. As you say, welding a gusset may be the solution to this issue without having to redo anything. I can't imagine that 1 1/2" square tubing would have flex issues albeit it is quite thin.


You don't need 2 in. tubing. I would use a minimum of 14 gauge Tubing, .080. Most tubing from the yard is 16gauge, .060. Try to mount the arm with less of a 90 degree to the trailer or gusset the arm on the trailer and gusset the bottom of where you connect the miter cuts in the arm. Also, if you redo the arm over again, better to run it rotated at 45degrees, like diamond shaped. Try grabbing a 10 stick of tubing and put one end on the ground then push pull down on it to see how much it flexes. Now rotate it 45degrees and do the same. You will see the flex is much less. It will be stronger this way with less flex. Thats how i have mine but mine is radiused. The main part is to not have so much of a 90 degree at the connection to the trailer.

Heres a sketchy sketch.

Wow, thanks for the info. I will first try to add add a gusset at the bottom 90° weld. What is the gauge of your typical front yard drive gate? It's about the same thickness. I definely will use a much larger gauge on my next one if I can't fix on this one. You learn from your errors and I am having fun perfecting this.
 
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After you get this one dialed in I guarantee you will most likely build another with less the amount of labor hours. I wouldn't use any larger then 1.5inx.090 tubing. You will be fine with .080 if you mount it rotated and keep your angles not to sharp. The Gusseting on what you have should hopfullu do the trick. The main thing on these trailers is to still keep them light so that you get max power out of your engine. You want the engine to push you, not you plus all kinds of extra weight. This way, when you want to do a long distance run, you know you can stack on extra gear without putting to much strain on the engine so as to lose alot of power. The 6.5 is pretty hefty as is so the engineering of the trailer has to be correct to its power. Keep us posted and we look forward to hearing or seeing a test run.
 
Well, as for the engine's starting issue I purchased an assorted box of micro bits from harbor freight for $5.xx. LOL when they say assorted, they mean random as ****. I searched through 10 boxes till I found one that had at least 1 bit that had #73 written on the shaft. I then drilled out the idle jet by hand and tested it out.

I was very happy with the results. On a cold start: choke on, pull rope, give a little gas for the idle to raise, turn off choke and ride away.

On hot start: pull rope, give a little gas to raise idle then ride away. Everytime I try to make a video, something happens. While recording, the engine slipped and the chain came off. The reason was that the mounting screws and area were soaked in oil. Just gotta clean it, and put the chain back on.

Here are some crappy cell phone pictures.

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EsQueue writes:

" The problem is that with moderate and heavy acceleration, there is a jerking feeling. Not
a smooth acceleration unless I feather it until I get to above 25 and then it is smooth from there. I don't always want to go that fast though. That is the reason why I thought that the arm flexing has to be the cause of this acceleration issue. As you say, welding a gusset may be the solution to this issue without having to redo anything. I can't imagine that 1 1/2" square tubing would have flex issues albeit it is quite thin.
"

I got to thinking about my experiences with larger 4 strokes & recall feeling the power pulses under hard acceleration when still in the lower RPM range. Remember, only every other downstroke of the piston is a power stroke and 4 strokes are lower RPM and torquier engines. Is it this or something else? If there is springiness in the curved tongue under power, you might be having a resonance caused by the tension in the tongue building up til it's fully resistant, then losing traction which allows the tension in the sprung tongue to release, followed by loading up again etc. If so, it would be a 'juddering' effect at a lower frequency than the power pulses.
Someone traveling alongside & behind you could see that, if it is happening.
These large engines have the power to be geared for speed which means initial acceleration RPM will be low and each powerful stroke will be felt, especially if your centrifugal clutch has a low engagement RPM. Probably nothing more than an irritation. I'm a strong proponent of pushers and want to find out as much as possible about any problems with them & their solutions so please let me know your conclusions.
 
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Dennis thanks for that, I tried some minor things and I noticed that stiffening the rear suspension of the bike greatly reduces this jerk. This leads me to believe that the push against the seat-post may be causing a lifting in the bike's suspension. I also found that feathering the throttle eliminates this issue.

I haven't gotten to the gussets as you suggested earlier but I will and definately give you the results.

BTW, I picked up a lincoln weld-pak 100 flux-cored welder so there should be less shameful welds. :)
 
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Hi, Here Is A Pic Of A Simple Trailer Connector. U Could Use Plastic, Hard Wood, A Short Piece Of Pipe And Weld Ears On It. Telon Block, Etc. Ron
 

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Hi, Here Is A Pic Of A Simple Trailer Connector. U Could Use Plastic, Hard Wood, A Short Piece Of Pipe And Weld Ears On It. Telon Block, Etc. Ron

Fortunately, my hitch is one of the stronger parts of my build. Thanks for that though.
 
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