Pull Start Design Flaw and Fix

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Hello Moto!

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If you look at the first picture you can see that there was some major rubbing going on. At first I thought it was the outer cups of the insert that goes over the magnet. I was wrong. What rubs on these things is the two big bolt heads on that piece which you can see in the second picture. I ran this thing over 100 miles before I realized that it was the bolt heads and that it could be fixed.

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You can see in this picture the bolt heads that I'm talking about and also that they are the parts rubbing.

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In this picture I show my solution. It's a quite simple one and works perfectly. All I did was grind down the majority of the bolt heads with a sanding disc. I would say a good 3/32 of material was removed. Though there is still juuuuust enough to get a wrench on there but that will never be necessary.

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This final picture shows that my solution is in fact a solution lol. I colored the tops of the shortened bolt heads with a black sharpy to check for any friction or rubbing against the surface. This picture was taken after the engine was running for a good amount of time. Plenty of time to show if there is any rubbing and there is no black removed.

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So if anyone ever installs a pull start it would be wise to do what I've done before ever even installing it. It took me over 100 miles of riding and a lot of metal shaving dust in my magneto housing before I came up with this solution. Just thought I'd pass this on to any pull start users like myself. I can't live without these things lol.
 
By the way the 100 miles of riding was done on my old bike. I removed the pull start from that and I am using it on my new skyhawk build until a new one comes in the mail for this one. I wanted to get this thing started without the drive chains set up so I borrowed it from my other bike lol.
 
This is a good newbie reference thread that I'll definitely bookmark. I know fer sure that the pedal crank won't clear the pull start adapter on my own bike, but I have no problems with that, so long of course as the engine STARTS. This is my last resort option...after I get through all the other start engine troubleshooting steps.
 
I don't think the pedals will ever clear a pull start housing on any stock bike. I have 130mm bottom bracket with angled pedal arms give about an extra inch with the bend. After installation I have about 3/8" clearance from the pull start. I will give you a link to a better set of bent pedal arms. These ones are sold by boygoesfast on eBay. These are way better than the black ones that say gasbike sells. The boygoesfast ones are a 170mm pedal arm length and are chrome. Also, you can buy just the crank set by itself if you don't need the whole bottom bracket kit. I used an american to euro bottom bracket adapter and utilized a 130mm sealed bottom bracket. The black cranksets that you see have a very short pedal arm length and a much bigger bend in the arms. I have one on my other bike and it is terrible. The pedal arms are so short it's hard to pedal. IF you have to get a bent pedal arm crankset..get this one!

http://www.ebay.com/itm/191548045399?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
The only pull start I used stopped winding itself back, rubbed a lot, then the nut that keeps the spring arm thing on the magnet came loose, got caught up in the internals, got shot through the pull start assembly (litteraly looked like a bullet hole, litteraly) and bent the crankshaft arm that holds the magnet, had to walk home with my bike, then inspection revealed the arm was snapped.

After replacing the crank I found it was the wrong kind, needed a new piston, and long story short my bike never ran good after that day, it's currently a yard decoration at my friends house..

I've never used a pull start since then.
 
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