12 replies to this topic

[bloke]

Hi all, I just fitted a service kit to the hif38 carb on the Min and set it up as per the usual blurb and it runs really well, but I thought I would dig out the Gunsons Gastester and give it a whirl an see if I was in the ballpark to pass the emissions test when I take it for it’s mot.

So, I followed the instructions to the letter, let it settle for 8 mins and calibrated it to 2% on the screen, went for a drive for about ten minutes, parked up and shoved the pipe up the exhaust.
The co reading went down! In fact it went down to .77%

I thought it was supposed to go up. I know the Min is a good little car, but I don’t think it could suck co out of the air

I know this gadget is a bit poo in general, but it is just for curiosities sake really. What am I seeing here and am I doing something wrong, or is this thing just hopeless bin fodder.

Thanks in advance..

[icklemini]

sounds like you are running a tad lean...

[lrostoke]

Is the tickover steady, or does it hunt ?? What revs are you checking at.
When my gunsons shows readings that low I'm running weak.

[minotaur]

sorry to hijack,...i've recently dug out a gastester pro but the tube that sticks in the exhaust is missing, can anyone give me the length and internal diameter of the original one supplied so i can make a replacement please, thanks

[L400RAS]

sorry to hijack,...i've recently dug out a gastester pro but the tube that sticks in the exhaust is missing, can anyone give me the length and internal diameter of the original one supplied so i can make a replacement please, thanks

I have leant mine out to a friend; if you haven't got your answer in 1 week - pm me and i will have mine back to measure

[bloke]

Hi there, the engines running at about 800 rpm or so, it does hunt a tiny bit but not too bad. So, on the reading on the front of the gastester should I set it to 2.5%-3% ish or do I add the 2.5%-3% to the already 2% on the gasterters meter?

What do you guys try to aim for, for a meter reading.? (Thanks for the replys so far by the way) (P.s. Minatour, just use a piece of copper tube that will squash into the flexy tube, from a hobby shop it works great 7mm outer 6mm inner)

Edited by bloke, 22 May 2011 - 09:28 AM.

[L400RAS]

Don't add any readings to the baseline figure. You'll need at least 2.5 on the meter to have the car running right. The meter is only a starting point; run the car down the road and richen it up until you are happy with it. 0.77% is too low though.

Edited by L400RAS, 22 May 2011 - 09:28 AM.

[bloke]

Don't add any readings to the baseline figure. You'll need at least 2.5 on the meter to have the car running right. The meter is only a starting point; run the car down the road and richen it up until you are happy with it. 0.77% is too low though.

Cool, thanks. I'll give it another go after a bit of lunch, that way I can warm up the car coming back from the pub.

[SMP]

I bought one of these gas testers a few weeks ago and found that it is brilliant - except for one small point - it reads exactly 2.0% high !

I know this because the only thing the mini failed on was emissions and I had to get it fixed - and I wasn't paying somebody else to do it.

Cross calibrating against the mot emissions machine I found that the tester reads 2.0% high. The tester is calibrated in air to read 2.0% so I figured the instructons in the box were out of date. So I rang gunsons. No - they said - the instructions are still good.

Anyway all I did was take 2% off the readings. Next time I will calibrate to 0% in air.

Anyway allowing for my adjustment above it went thru the test at 2.4% - spot on what I was aiming for. As stated above this was right on the edge of how low you could go before the exhaust idle note started to "puff" every now and then. Also I think that if you set it any lower than this the HC starts to go up - mine did. 3.9% CO gives 400ppm HC, but 2.4% CO gave 700ppm HC. There's a chart that explains it in the instructions.

The thing I did notice is you really do have to following the intstructions about letting the machine settle down for a good 10 mins before using it.

Cheers
Steve

[minotaur]

Hi there, the engines running at about 800 rpm or so, it does hunt a tiny bit but not too bad. So, on the reading on the front of the gastester should I set it to 2.5%-3% ish or do I add the 2.5%-3% to the already 2% on the gasterters meter?

What do you guys try to aim for, for a meter reading.? (Thanks for the replys so far by the way) (P.s. Minatour, just use a piece of copper tube that will squash into the flexy tube, from a hobby shop it works great 7mm outer 6mm inner)

thanks great, and the plastic tube, which is obvoiously 7mm inner diameter but how long is it from the tester to the copper/exhaust piece, thanks

[lrostoke]

I found how far you put the probe up the exhaust changes the readings. I've now got a piece of tape round the probe so I know how far to insert

[bloke]

I bought one of these gas testers a few weeks ago and found that it is brilliant - except for one small point - it reads exactly 2.0% high !

I know this because the only thing the mini failed on was emissions and I had to get it fixed - and I wasn't paying somebody else to do it.

Cross calibrating against the mot emissions machine I found that the tester reads 2.0% high. The tester is calibrated in air to read 2.0% so I figured the instructons in the box were out of date. So I rang gunsons. No - they said - the instructions are still good.

Anyway all I did was take 2% off the readings. Next time I will calibrate to 0% in air.

Anyway allowing for my adjustment above it went thru the test at 2.4% - spot on what I was aiming for. As stated above this was right on the edge of how low you could go before the exhaust idle note started to "puff" every now and then. Also I think that if you set it any lower than this the HC starts to go up - mine did. 3.9% CO gives 400ppm HC, but 2.4% CO gave 700ppm HC. There's a chart that explains it in the instructions.

The thing I did notice is you really do have to following the intstructions about letting the machine settle down for a good 10 mins before using it.

Cheers
Steve

Sweet, that's really handy to know, I set it today at 2.4 and it runs much better but if what you are saying above is right then i'm still 2% out. I'll have another go tomorrow. I did think it was almost impossible to get it even close to 2.4% but there was a sweet spot around 4.5 ish where it was happy.

(P.s. for minator the length of flexy pipe is about three feet)

[bloke]

Final setup today, set to 2.5 (minus the 2%) and Min is as smooth as can be. Idle is rock steady at 900 rpm and drives like a new car. Carb service kit was worth every penny. Thanks everyone for the help, and happy Mini-ing