Let's try some Redex...

[JonB]

I was looking at a clip from 5th Gear on YooTooob the other day, showing an old car being rejuvenated somewhat by a number of cheap repairs.

https://www.youtube.com/watch?v=efIJHf7h5kI

It's entitled "Can You Restore Lost Power To An Old Engine?", and it tries several cheap things that might improve the power output of the engine. One of them was to use Redex, once. This gave the most improvement, yielding about 6 bhp after the tank had been used.

As I don't know how clean the inside of my carbs is, I've dumped a bottle of Redex "fuel system cleaner" in my tank and refilled it. This is the same stuff that was used in the 5th Gear test. Then, I took the car for a short blast. Initially it was hesitating at about 3000 RPM, but after a while it settled down and was accelerating quite hard. I'd just refilled with 99 RON Super Unleaded, so I thought perhaps that was causing it to hesitate, as it wasn't doing that before...

Anyone else tried Redex? What improvements did you notice?

[69S4]

Nice to see you're trailblazing another path Jon I've just got a bottle of Redex ready to tip in, but whether it goes into the Elan or one of my bikes depends on which one misfires the most ...

[JonB]

Took the car out for a bit of a blast today, after resetting the timing, balancing the carbs and setting the idle mixture (which was way too rich). It's quick and delivering good, smooth power. The Twink is pretty rev happy - I saw 6500 at one point.

This may be down to Redex, or not. I may see some improvement once the tank is used (and the Redex has all passed through the system). So far though, I reckon it's a fiver well spent.

[Chancer]

Nothing to do with setting the ignition timing, balancing the carbs and adjusting the idle mixtures then!

Shame the smilies dont work with Firefox as you earned a rolling eyes one.

[JonB]

Nothing to do with setting the ignition timing, balancing the carbs and adjusting the idle mixtures then!

Shame the smilies dont work with Firefox as you earned a rolling eyes one.

Errrm, sorry. I forgot to add, it went really well before I tuned it. So no, very little to do with that!

<-- There you go! Next time you want to use it in Firefox, you can type a colon then "roll" then another colon with no spaces.

I've been putting off setting the idle mixture since last November when I got the car. Been too busy with other more pressing matters as you're probably aware. I found that after I'd set the timing previously, I'd not tightened the dizzy up properly and it was a little loose. And as for the balancing, that is just good form as I had the air box off to get at the distributor clamp.

To get back on topic - it's only a fiver so I thought I'd give it a try. Seems to have improved the car.

[Chancer]

You must have had it very close to perfect before the tuning then as all those things can make a huge difference to driveability if only slightly out.

So did you tune the car to get it as good as you could and then try the redex after the test drive? That would be meaningfull and revealing.

Lets try "very happy" with your astuce :veryhappy:

Mmm I need to work out what a colon is aside from the one they put an airline in every 5 years (laughing smily)

[JonB]

Timing may have been spot on, and the carbs had been balanced, but I hadn't done the idle mixture when I first dumped Redex into the tank. To be honest, I was looking to give the jets a clean on the cheap, and it's improved matters. I think the timing is still off though, as (under acceleration) the engine stutters and the rev counter twitches. I suspected a bad connection at the coil but it's all OK. Need to get the timing light out again!

PS big smile is a colon filled by a "D".

[Bud English]

PS big smile is a colon filled by a "D".

Not touching that one.

[JonB]

Well, I am amazed (again).

I checked the timing very carefully this afternoon and found the distributor was completely loose. No wonder it was stuttering! I've put a blob of white paint on the pulley notch and reset the timing (to 12 degrees BTDC @ 1000 RPM), then checked it is advancing properly at higher engine speeds.

Whilst testing at 4000 RPM I noticed the exhaust header glowing cherry red. Yikes, no wonder the clutch and engine mount give in so regularly. Must do the heat shield mod pronto!

Have ensured the dizzy is seated properly and tightened it...

I'll be test driving later today, hopefully ready for Goodwood!

[Chancer]

Your timing is retarded at 4k RPM or you have a weak flat spot but the latter would be very noticeable while driving, try a timing swing at 4K RPM to see if i am talking rubbish or not (evens chance ) and then have a look at the centrifugal advance.

Editted, just oen header or all of them?

difficult to tell the individual temperatures as its way beyond the range of most IR thermometers, if just one header and not both barrels of the same carb then its a partially blocked jet or drilling.

[JonB]

They were all pretty hot, glowing a dull orange.

I did check it at 4000RPM and it looked reasonably correct (insofar as you can measure 21.3 degrees with those timing marks). Other thing I noticed was that the timing mark (on the pulley) is not jumping about at all. I think that means the dizzy is in good nick.

Anyway, one quick test drive later and I think it is much improved. Jolly fast (noisy, too) and smooth with it.

[gav]

Jon

Mind the noise limits at Goodwood.

Might be worth taking a spare can to put on the back in case you are too loud.

I have a TTR fast exhaust box and I hit 96 db on the sound test at the last sprint I ran at. Just squeaked through.

.... and do let us know how you get on

Gavin

[JonB]

Hi Gav

I won't be taking the car on the track. No places left, so I'll be there's for the social side of the day.

Cheers
JonB