G2 420 clone - stall on deceleration

[mr_camera_man]

So I have a G2 with a Genkins 420cc from Amazon that I completed at the end of last season. So I finally have a chance to get it out some now that I’m back at the camper. Using the stock starter generator and relay mod for pedal start/stop that’s been outlined here before. Stock G2 fuel pump vacuum-driven with a tap on the carb spacer.

Starts fine but sensitive to only starting with just enough pedal to turn the starter. Stops fine.

The only major issue is that from about 3/4 to full throttle, deceleration will cause it to stall. Immediately going back to full throttle won’t save it. And at this point it’ll take a good few seconds of cranking to get it back. Major PITA when slowing down for turns or traffic, etc.

Not even sure where to start with this one… any ideas? Thanks!

[augiedoggy]

Originally Posted by mr_camera_man

So I have a G2 with a Genkins 420cc from Amazon that I completed at the end of last season. So I finally have a chance to get it out some now that I’m back at the camper. Using the stock starter generator and relay mod for pedal start/stop that’s been outlined here before. Stock G2 fuel pump vacuum-driven with a tap on the carb spacer.

Starts fine but sensitive to only starting with just enough pedal to turn the starter. Stops fine.

The only major issue is that from about 3/4 to full throttle, deceleration will cause it to stall. Immediately going back to full throttle won’t save it. And at this point it’ll take a good few seconds of cranking to get it back. Major PITA when slowing down for turns or traffic, etc.

Not even sure where to start with this one… any ideas? Thanks!

stock fuel pump not delivering enough fuel to keep up on the top end? I mean the fuel pump is sized for less than 300cc right?

[raydhd]

Probably carb is too lean. Best solution is to add an adjustable from NRracing or ECcarbs. Another option is to carefully drill open the main jet. P.S. I use a clear glass fuel filter so I can see at all times how fuel delivery from the pump is. I didn't have delivery issues with the near stock VC 460 gen 1 BUT BIG TIME fuel delivery issues with a heavily modded VC 460 gen 3

[mr_camera_man]

Hmm… so it will run at full throttle with seemingly no problem until I either Ron out of road or it throws the starter belt. That’s a new one as of today, fun…. So I don’t think it’s outrunning the fuel pump?

I’ll pull the plug later after it cools down and see if it’s looking too lean. Choke didn’t seem to make a difference, and I don’t hear any backfiring.

[raydhd]

Are you using a governed engine? Again is that a UT1 or UT2 unit ?

[mr_camera_man]

Governor is disconnected. Guess I’m a newbie, not familiar with UT1 vs UT2?

[raydhd]

Some of the clones use an electronic governed ignition coil. There are the UT2's. The UT1 just uses the mechanical governor. Most of the clones are UT1's but Honda and Lifans are UT2's. Don't know what other units are UT2's. The picture on line of the Genkin looks to be a UT1. The UT1 has the single black wire coming out from the coil. The UT2 has red,black and yellow wires from the coil.

[mr_camera_man]

Definitely mechanical governor. I’m using the governor arm as improvised throttle linkage.

Edit: and of course the correct plug socket is 2 hours away. To be continued…