QMB139 High Torque Starter - the myth - BUSTED!

[dexameth]

So there is somewhat a controversy over the high-torque starter for the QMB139 motors. People are lead to believe that if you big bore, increase compression, etc... that you need a higher torque starter because the stock one just won't cut it.  

Nope.



This is a 52mm cylinder bore with a slight domed piston and big valve head, 44mm stroke motor pushing 205psi. Watch its first start below.



This setup has a 12v 3.5ah battery (tiny!) and a new stock starter, using the old used bendix and solenoid. As you can see it fired right up at 205psi (I need to tune the carb but that's another story).

Maybe these so called stock starters are unlabelled high torque... Hmm... 

[eclark5483]

On my kids, the first few runs, it was a bit rough starting. I attribute that to rings not broken in and cheap Chinese battery. I switched it out for a Battery Tender high CCA Lithium and now she pops off in a split second. Helps to have those valves adjusted perfect too. Only issue I have recently ran into is the bendix not kicking out all the time. Though this only occurs when it is cold. My best guess on that one, is the lube used on it is useless, gonna tear it apart, clean out the old stuff, re-grease and see how she goes when it's cold.

[fugaziiv]

To clarify, HT GY6 150 starters are a very real thing however.


Matt

[mrkswthwrth]

Hey dex nice scoot, and nice ink! Im getting a blackflag tattoo this week

[Kick start]

I'm using a stock starter they work fine