Very Erratic Idle Hyper .21 3 port turbo

[CJM]

Hi folks

 

I broke in my engine recently as per manuf recommendation, but since new noticed I had an issue with the HSN, has been very tight to adjust since new, acting like a spring during small adjustments, and found it difficult to tune.

 

I found when removing the HSN to check after breaking  in the engine that the oring was split with a large chunk jammed between the needle and housing.

 

Spoke to the UK distributors and they sent a new carb.  (Superb service BTW)

 

Replaced the carb today with the new unit they sent, checked was at correct needle start points after running in the engine  (2 1/4 out on HSN and just out from flush on LSN)

 

The idle is dancing about like it's playing a song after warm up,  revs OK up to full accel, good smoke trail, but did occasionally stall, adjusted idle screw and no difference.

 

I did try small adjustments on the LSN but didn't seem to change.

 

Any ideas folks?

Edited March 15, 2022 by CJM

[locky]

Take good HSN needle out of new carb and put it in old carb, then fit old carb. Process of elimination.  Perhaps lubricate O-rings if too tight.

[Nitroholic]

Erratic idle is most likely an air leak.

 

Possibly around the carb neck, as thats something you have disturbed.

[CJM]

That was my thinking as well, pulling air in from somewhere, seems to get worse as engine heats, cuts out about 5 secs after video ends.  Been scratching my head with this engine for days now.

 

 

Was doing it with the old carb, and then the new one as well.  Replaced the orings on the carb and the HSN and tried again oiling up LSN, HSN and carb orings, took all settings back to default, fresh fuel, new glow plug try again.  Same

 

As it is a new car I have sent it away for inspection, suspect a bad oring or gasket on the engine.

 

Will see what they come back with on Monday 

 

Anyone seen this before can not get rid of this no matter what I try.

 

Tried tweaks on the LSN and HSN from factory and does not seem to improve either way.

 

Got me stumped, then again I have not got that much experience, but would not expect this at factory settings.

 

 

Edited March 18, 2022 by CJM

[locky]

If it did it with original carb then possible air leak.  I usually take back plate off and inspect internals then reseal with gasket sealant to ensure air tight seal. Also seal carb and pinch bolt with sealant. Always best to have another glow plug to rule that out. Sometimes plugs that look good can misbehave.

Edited March 18, 2022 by locky