27 replies to this topic

[TopGearRules]

What needle in the carb for what engine?

 

Its a HS4 non-waxstat carb, and its a 998 A+ engine. All was okay before I fiddled around with the mixture a bit. I've must of affected something else while doing it but I have no clue what.

[jaydee]

By your first post it doesnt look its been running as it should

[TopGearRules]

By your first post it doesnt look its been running as it should

 

I'm glad you said that as I think the carburettor has not been calibrated right. I'll contact the original seller and see if they can give me some advice. I might end up reconditioning my old carb and stick it back in. Are the reconditioning kits easy to fit, or would it be best to get a professional to do it? Thanks, Al

[jaydee]

 

By your first post it doesnt look its been running as it should

 

I'm glad you said that as I think the carburettor has not been calibrated right. I'll contact the original seller and see if they can give me some advice. I might end up reconditioning my old carb and stick it back in. Are the reconditioning kits easy to fit, or would it be best to get a professional to do it? Thanks, Al

 

 

 

I dont think its a problem with the seller, if the needle valve was stuck then ok, but you cant blame it on the seller for needle selection, you have to select the needle to suit your application. Unless they told you that throttle spindle bushings were replaced, and its not true and now now they're leaking.

So, before throwing money in the bin, make sure that you dont have air leaks at either the join between carb and the manifold, the throttle spindle, and that the vacuum pipes are connected.

Also check that teppet clearance is ok.

Dont forget to check what needle you have in the carb and reprt back.

[TopGearRules]

Hi there,

 

Sorry to drag this thread out of its grave but I'm still having some occurring problems! Even though the carb has been tuned several times, I am still having trouble when idling. When the car slows down from speed to a stop, it idles fine (at around 850 RPM). However after a minute or so of idling it starts to really bog down, and it can fall to 400 RPM, where you need to their pull out the choke or it stalls. I read somewhere that it could be due to damage to the cylinder head, and considering its done almost 100K miles I fear it maybe the case. Does this sound like a plausible reason for it bogging down. I had the same issues with my old carb so it has to be the case?

 

Many thanks, and sorry for being a pain!! Alex 

[jaydee]

I'll be honest..cant see a relationship between your issue and a 100k miles cylinder head, but check tappets clearance and rocker pad wear.

This sounds more like something to do with a sticky butterfly/spindle

[TopGearRules]

I'll be honest..cant see a relationship between your issue and a 100k miles cylinder head, but check tappets clearance and rocker pad wear.

This sounds more like something to do with a sticky butterfly/spindle

 

Hi, thanks for the reply. I recorded this video just to show the problem of the rough idle. You can see from 0:18 it idles at 800 RPM and then drops down to around nearly 500, where it feels like it wants to stall. I think I may have to take the carb our and get it checked out by a specialist.

 

 

Thanks for your help   Alex

[jaydee]

Your car just needs a litlle tune up

Check the ignition advance first then set up mixture, 2.5-3.0 CO at idle, and idle speed to proper 800-900 rpm

[TopGearRules]

Your car just needs a litlle tune up

Check the ignition advance first then set up mixture, 2.5-3.0 CO at idle, and idle speed to proper 800-900 rpm

 

Ahhhh okay, I will get it booked in with a mechanic and hopefully they will be able to tune it up. Does anyone know if Mini Speed (near byfleet) does such a service? Many thanks, Alex

[jaydee]

Drop a PM to Scott on here

They're usually helpful at minispeed

[Jordie]

Bouncing revs....maybe an air leak? Try spraying some WD40 around the inlet manifold to head joint and around the carb to inlet and see if the revs change at all.

 

Id consider lifting the idle, this time of year espically, with all your gizmos running in winter. I raise the idle speed a little for winter driving.

[Scott@minispeed]

 

Your car just needs a litlle tune up

Check the ignition advance first then set up mixture, 2.5-3.0 CO at idle, and idle speed to proper 800-900 rpm

 

Ahhhh okay, I will get it booked in with a mechanic and hopefully they will be able to tune it up. Does anyone know if Mini Speed (near byfleet) does such a service? Many thanks, Alex

 

 

Hi Alex, yes we can help with this. We can offer a static tune (timing, mixture and idle speed check and adjust) for £35+VAT or a full rolling road tune at £70+VAT per hour. Give our workshop a call on 01932 400567 to book in.

[TopGearRules]

 

 

Your car just needs a litlle tune up

Check the ignition advance first then set up mixture, 2.5-3.0 CO at idle, and idle speed to proper 800-900 rpm

 

Ahhhh okay, I will get it booked in with a mechanic and hopefully they will be able to tune it up. Does anyone know if Mini Speed (near byfleet) does such a service? Many thanks, Alex

 

 

Hi Alex, yes we can help with this. We can offer a static tune (timing, mixture and idle speed check and adjust) for £35+VAT or a full rolling road tune at £70+VAT per hour. Give our workshop a call on 01932 400567 to book in.

 

 

Thanks for the information, I will give you a ring soon! I'm not free in January since I have a university trip abroad to go to, but I should around in February. Many thanks, Alex