Dual Engine timing issue ?

[KurzKranks]

Alright so imma throw 2 of those 49cc minibike engines into a razor mx500 and I'm just stuck on if there would be any timing issues even when I setup a link to pull both throttles at the same time. I have a pretty good understanding of how these engines work I'm just scared of one seizing on the go because theirs a lack of fuel for the rpm or one engine dragging the other. I've seen it done as I described and seems to work fine. Just wondering if anybody has concerns.

 

[Chainlube]

Timing issues, no. You will need to synchronize the two carbs, best way is a twin carb bike or snowmobile cable.

 

[DAMIEN1307]

Timing issues, no. You will need to synchronize the two carbs, best way is a twin carb bike or snowmobile cable.

That same principle was exactly what was required to sync my dual SU carbies on my Triumph Spitfire and my MG back in the 70s, making sure that i could see the slides inside moving identically at the same time by removing the air filters and then when moving the throttle, to visibly see the slides motion themselves at exactly the same time and distance to be in sync...DAMIEN

 

[Chainlube]

That same principle was exactly what was required to sync my dual SU carbies on my Triumph Spitfire and my MG back in the 70s, making sure that i could see the slides inside moving identically at the same time by removing the air filters and then when moving the throttle, to visibly see the slides motion themselves at exactly the same time and distance to be in sync...DAMIEN

SUs have a throttle plate, so they can be actuated at the same time with one cable, where as the OP is looking at two different motors and a cable to each.

 

[DAMIEN1307]

I was only saying that the same "principle" applied as i am aware of the cable situation necessary for the OPs setup vs a throttle plate...DAMIEN

 

[Karl Snarl]

Alright so imma throw 2 of those 49cc minibike engines into a razor mx500 and I'm just stuck on if there would be any timing issues even when I setup a link to pull both throttles at the same time. I have a pretty good understanding of how these engines work I'm just scared of one seizing on the go because theirs a lack of fuel for the rpm or one engine dragging the other. I've seen it done as I described and seems to work fine. Just wondering if anybody has concerns.

Get a set of vacuum gauges. Bench sync the carbs, then after you get your drive train set up, sync them like you would any motorcycle carb rack. Your best bet on meshing the engines is to let them each have a freewheel or sprag clutch to a jackshaft that then runs to the final drive. That way they won't fight each other, and if one seizes or drags, the other can still get you home.