Help starting 28 6p engine

[hamedhbb]

Hi there
Would appreciate if someone helps me with tuning my engine.
I could manage to get it running after few hours of try. It is a mac star 28 6p engine. I use a 25% fuel.

I touched all the tuning first using factory settings mentioned in the manual. But I ended up using power supply to feed my plug and increase the current by three times. Then I had to adjust the idle because it was cutting out after several seconds. Then let it run for a while to get warm. The next issue was If I went full throttle, it did choke or otherwise didn’t have power at all if I tried accelerating. If I gradually throttled It could cope. I adjusted the full speed trim and it got way better. I understand these but what I don’t get is why I need igniter and leave it on for 10sec even when the engine is hot before pulling the handle. I literally tried to pull the handle a few seconds after it cuts out. Is this normal?

Next questions are:
-Is it normal that it used 2/3 of a thank within 30mins of driving around slowly?

-is it normal that after cold start the engine was revving up considerably to the point that car accelerated on its own?

Thanks

 

[cbaker65]

Hi there
Would appreciate if someone helps me with tuning my engine.
I could manage to get it running after few hours of try. It is a mac star 28 6p engine. I use a 25% fuel.

I touched all the tuning first using factory settings mentioned in the manual. But I ended up using power supply to feed my plug and increase the current by three times. Then I had to adjust the idle because it was cutting out after several seconds. Then let it run for a while to get warm. The next issue was If I went full throttle, it did choke or otherwise didn’t have power at all if I tried accelerating. If I gradually throttled It could cope. I adjusted the full speed trim and it got way better. I understand these but what I don’t get is why I need igniter and leave it on for 10sec even when the engine is hot before pulling the handle. I literally tried to pull the handle a few seconds after it cuts out. Is this normal?

Next questions are:
-Is it normal that it used 2/3 of a thank within 30mins of driving around slowly?

-is it normal that after cold start the engine was revving up considerably to the point that car accelerated on its own?

Thanks

This maybe your issue ,along with your idle gap set too big!

{ -Is it normal that it used 2/3 of a thank within 30mins of driving around slowly? }

The idle gap on the carb barrel should be set to about a width of a paper clip or from
0.45 mm to 0.55 mm!

Your engine maybe set too rich an loading up the engine causing the plug to foul ,hence causing
the engine to die after pulling the glow igniter ,also your engine starts off sluggish an or you have
to keep the revs up to keep it from dying ,that is an indicator that your engine is too rich on fuel!

My suggesting is ,get a new glow plug ,reset the carb to factory settings ,set your idle gap tothe 0.50mm
an start tuning from there ,you only tune an turn your HSN needle in in small increments like at 1/8 turns
at a time ,just until the engine starts to get a snappier response an you can get a high speed pass with
out it bogging or stuttering!

Here is a good vid to watch for explanation & fine tuning the engine as it is hard to diagnose an give
engine tuning advise with out knowing what is the engine is doing!

 

[hamedhbb]

This maybe your issue ,along with your idle gap set too big!

{ -Is it normal that it used 2/3 of a thank within 30mins of driving around slowly? }

The idle gap on the carb barrel should be set to about a width of a paper clip or from
0.45 mm to 0.55 mm!

Your engine maybe set too rich an loading up the engine causing the plug to foul ,hence causing
the engine to die after pulling the glow igniter ,also your engine starts off sluggish an or you have
to keep the revs up to keep it from dying ,that is an indicator that your engine is too rich on fuel!

My suggesting is ,get a new glow plug ,reset the carb to factory settings ,set your idle gap tothe 0.50mm
an start tuning from there ,you only tune an turn your HSN needle in in small increments like at 1/8 turns
at a time ,just until the engine starts to get a snappier response an you can get a high speed pass with
out it bogging or stuttering!

Here is a good vid to watch for explanation & fine tuning the engine as it is hard to diagnose an give
engine tuning advise with out knowing what is the engine is doing!

Thank you very much. Very informative. After watching the video I tried again and got it running. I am sure it’s not the best tune but it’s more than what I need to get going. I was using a wrong plug (R4) for the 25% fuel that I was using. Managed to find a N3 in the toolbox and that solved the starting issue. Still need the ignitor on to start after a stall when engine it hot but at-least it starts with one pull.
The only issue I have now is that if I go full throttle suddenly the engine chokes. To get around it I limited the throttle servo to move a little (5mm) at full throttle. The car is still fast but this doesn’t feel normal to me.
He doesn’t cover this in the video but I think it correlates with what he talks about too lean HS.