17 replies to this topic

[Zacherius]

I have a 1981 Austin Mini HL AUTOMATIC.

I just fitted a Stage One kit from MiniSport, so thought it would be best to have a rolling road tune to get things right.

The guy did the whole tuning thing ( blasting the engine to bits, "altering" the new needle, adjusting the timing (by hiting the side with a screw driver and hammer (nice and gentle hey )) and changing the mixture.

It is better don't get me wrong, it actually sounds nice on idle instead of like its being killed. If you put your foot down it blasts away and is ok. BUT, driving normal ( as in light on accelerator ) it is not right, like the timing or mixture is wrong ? I was driving along a flat dual carriageway at 50 and it felt like it was going to start struggling, yet I was only slightly on the peddle, I put my foot down, it hiccuped and shot to 60 and seemed fine at 60.

It happened again on a 30 road that it was not right, I floored it and it went like a shot, then seemed fine at 40.

Seems to be set up to drive manic everywhere ??

Anyone have any ideas ? Not really wanting to go back to that garage as he has dented the bonnet, badly scratched the drivers door, knocked the exhaust so I had to fix that just outside the garage, and theres just something.... well, you know when you get that feeling !!!

[lrostoke]

If from what you describe of his workmanship and care is anything to go by, its possible he's made a bodge of altering the needle.

Could also check you have any oil in the dashpot. He may have forgot to put some in.

[Guess-Works.com]

check to see if the vac advance is still connected...

[Zacherius]

If from what you describe of his workmanship and care is anything to go by, its possible he's made a bodge of altering the needle.

Could also check you have any oil in the dashpot. He may have forgot to put some in.

Definately Have oil in Dashpot. I still have the old needle, I could try that an let you know ?!

[Zacherius]

check to see if the vac advance is still connected...

Right..... Big point here, HE DISCONNECTED THE VACUUM ADVANCE AND PLUGGED IT ?!?! HE TOLD ME ITS NOT REQUIRED !?!?

HELP ?

[Wil_h]

Sounds like the needle has been profiled for idle and flat out, but the cruise mixture is too lean.

More needle work required.

You could have a go yourself. looking at the needle profile, starting at the top/thickest end. The first cm is the idle part (dont change this) the next cm is the cruise part (you need to change this part) after this the profile is for midrange and flat-out (you say this is ok, so leave alone)

There are a number of ways to change the profile, but I tend to file a small flat (making sure that the flat is on the unsprung side of the needle (i.e. it won't rub on the jet). You only need to take a very small amount off. The other way is to use sme emery cloth and smoothe the whole area. Make a small change then test drive the car, then do a bit more if necessary (keep making small changes 'til it drives ok.)

EDIT: Reconnect the vacuum. Then see what happens. The vac advance is specifically for cruise conditions. Disconnecting it is a lazy way to set a car up. Ok if you only go flat out, but useless for a daily driver. Tell us the name of the garage so we can all stear clear.

Edited by Wil_h, 11 November 2008 - 01:21 PM.

[Zacherius]

Sounds like the needle has been profiled for idle and flat out, but the cruise mixture is too lean.

More needle work required.

You could have a go yourself. looking at the needle profile, starting at the top/thickest end. The first cm is the idle part (dont change this) the next cm is the cruise part (you need to change this part) after this the profile is for midrange and flat-out (you say this is ok, so leave alone)

There are a number of ways to change the profile, but I tend to file a small flat (making sure that the flat is on the unsprung side of the needle (i.e. it won't rub on the jet). You only need to take a very small amount off. The other way is to use sme emery cloth and smoothe the whole area. Make a small change then test drive the car, then do a bit more if necessary (keep making small changes 'til it drives ok.)

EDIT: Reconnect the vacuum. Then see what happens. The vac advance is specifically for cruise conditions. Disconnecting it is a lazy way to set a car up. Ok if you only go flat out, but useless for a daily driver. Tell us the name of the garage so we can all stear clear.

WILLFIELD MOTORS, ABERCYNON, S.Wales.

I got recommended to use it by Cardiff Mini Club, and the Mini Parts Centre in Barry so thought it would be good. The guy did have two cars ripped up with big engines that he said he uses for grass tracking. So goes Flat Out !
Maybe THATS his speciality ?

Who Knows.. He only ran it once after changing the needle, did say that it might need doing a few times but he never did.... Just once, Plugged the Vacuum, Altered the mixture, then took my money !
He did give me a reading which says 44bhp, BUT, only 18bhp at the wheels and he said thats because its an auto, it reads wrong on the machine ???

[Ethel]

I'd reconnect the vac advance 'n see what happens. It won't effect the idle or full throttle.

[998dave]

check to see if the vac advance is still connected...

Right..... Big point here, HE DISCONNECTED THE VACUUM ADVANCE AND PLUGGED IT ?!?! HE TOLD ME ITS NOT REQUIRED !?!?

HELP ?

Who was this man, you're meant to diconnect and plug it to set the timing, and then reconnect it afterwards!

This could be your problem...

[Ethel]

I would doubt the reading is wrong if it's directly off the rollers, though don't know how you can decide what it is without the gearbox as you have to measure the output through it. The losses must read high on run down as you can't declutch the engine without a clutch.

[mini_mad69]

Ive taken my car there, my car came out perfect I have absolutly no complaints about it. All he did with mine was take out the breather and block that off, are you sure it was the vaccum advance he removed and not the breather hose on the carb. My car came out with a nice idle, smooth acceleration with a nice big power band and nice cruising. My car used to miss a little at cruising speeds but would go alright when you put your foot down and he sorted it. you should give him a ring and tell him its not right, he'll probably give you some advice if not another tune.

Edited by mini_mad69, 11 November 2008 - 02:14 PM.

[Wil_h]

It's very difficult to measuer the BHP on an auto, so any reading is a very rough guide only.

[Zacherius]

Ive taken my car there, my car came out perfect I have absolutly no complaints about it. All he did with mine was take out the breather and block that off, are you sure it was the vaccum advance he removed and not the breather hose on the carb. My car came out with a nice idle, smooth acceleration with a nice big power band and nice cruising. My car used to miss a little at cruising speeds but would go alright when you put your foot down and he sorted it. you should give him a ring and tell him its not right, he'll probably give you some advice if not another tune.

OK. THIS SHOWS MY LACK OF KNOWLEDGE. I have tried and tried to contact the mechanic but no answer. He just rang me.

He said it was THE BREATHER he disconnected, and that he will FOR FREE redo the full tune, but before he does I need to contact Berlyn's (Motor Factor) and get a Different Jet as I have a "wax something bottomed one" if that makes sense, and it keeps re-adjusting itself so hard to get right. If I change for the older style Jet that stays where he puts it, then he can get it spot on...

Sorry guys, and sorry Willfield Motors..... But he didn't tell me I needed a new Jet, until I phoned him.

Cheers all for your help, but he will get it sorted.

Matt

[Guess-Works.com]

Right it's Burlen, but you can get the parts from Minispares, and it's a Waxstat Jet, works in a similar fashion to a thermostat, it has a wax fill which expands and contracts associated with ambient temperature, so in cooler temps it richens the mixture ( as air is denser when it's cold ).

and secondly you should not block of the breather as Minis have a closed circuit breathing system... now the engine is breathing to atmosphere...

All the things he's doing are perfectly ok and normal when dealing with performance engines, no vac, engine breathers are usually piped to a catch tank instead of the the carb.. changing the waxstat for a fixed jet... next he'll be taking the filter of and putting a ram pipe on it..

[mini_mad69]

Yeah thats the same as mine, he said to block of the breathers stops the carb from getting gummed up eventualy, I have now put a little oil breather filter on mine I know its meant to go into the carb but its done now. He's a sound guy and I trusted him with my car, he explained about the waxtat jet in my carb being a bit funny and said to upgrade to the later hif38, I think anyway, he seemed to know what he was doing and I highly recomend him to others. Oh and did you see the pictures of the mini race cars and mini autograssers in the corner of the workshop, he used to race them and metros, so he has alot of experience with them aswell.