Guys,
You may recall my posts, about a month ago, about my sudden loss of power and a dreadful, very loud "tappety noise" while travelling at speed.
To recap in brief I did the following (with outcomes in brackets) from the excellent advise from a number of you (esp Kryten who has PM'd very detailed methodical check lists as well):
1. Checked all valve lifters, rockers off with engine running, and all had good equal movements - too eliminate poss cam wear as problem (all ok)
2. Did "wet and dry" cylinder compression tests (all within 10 %)
3. Replaced ignition leads and coil (no change)
4. Replaced vacuum advance unit / soaked bob weights etc in Plusgas (no change)
5. Replaced Fuel filter (twice) - (slight improvement)
6. Plugs where only 1 mnth old when problem happened, so put old ones back - just in case (no change)
7. Checked float heights, needles and general condition of SUs (all checked out ok (at the time))
8. Double checked the air balance and mixtures of the SUs (good improvement / idling better and pulled ok but still major loss of mid range power)
Last weekend, while doing further checks, I noticed that one of the SU pistons was riding a lot higher up the dashpot than the other
. I stripped the SU and found that the jet tube / float inlet connection to the bimetallic strip had broken away from its housing and had risen up into the dashpot chamber. Quickly went onto Burlens website and ordered a new jet tube which arrived Saturday. Fitted it all up and rechecked air balance and mixtures (the offending carb needed major twists to the mixtures screw to get right) - bingo - took it for a spin yesterday and, wow, its like a new car (I wonder if in my 15yrs of ownership this may have been a worsening problem as I don't think its ever run so well - big grin on face). Incidentally, the loud "tappety noise" was a red herring to the main problem - it was a crack in one of the tubular header to cylinder head welds which created a small enough gap to give a metallic sound like tappets !!
In conclusion I want to repeat my gratitude to all of you that helped me to get this sorted esp, as above, Russ for all his Forum and PM details, which has saved me huge sums if I had to use a garage and, perhaps the bigger benefit, is that I have learnt loads as well.
Hopefully this may help others equally
Cheers
Ian
You may recall my posts, about a month ago, about my sudden loss of power and a dreadful, very loud "tappety noise" while travelling at speed.
To recap in brief I did the following (with outcomes in brackets) from the excellent advise from a number of you (esp Kryten who has PM'd very detailed methodical check lists as well):
1. Checked all valve lifters, rockers off with engine running, and all had good equal movements - too eliminate poss cam wear as problem (all ok)
2. Did "wet and dry" cylinder compression tests (all within 10 %)
3. Replaced ignition leads and coil (no change)
4. Replaced vacuum advance unit / soaked bob weights etc in Plusgas (no change)
5. Replaced Fuel filter (twice) - (slight improvement)
6. Plugs where only 1 mnth old when problem happened, so put old ones back - just in case (no change)
7. Checked float heights, needles and general condition of SUs (all checked out ok (at the time))
8. Double checked the air balance and mixtures of the SUs (good improvement / idling better and pulled ok but still major loss of mid range power)
Last weekend, while doing further checks, I noticed that one of the SU pistons was riding a lot higher up the dashpot than the other
. I stripped the SU and found that the jet tube / float inlet connection to the bimetallic strip had broken away from its housing and had risen up into the dashpot chamber. Quickly went onto Burlens website and ordered a new jet tube which arrived Saturday. Fitted it all up and rechecked air balance and mixtures (the offending carb needed major twists to the mixtures screw to get right) - bingo - took it for a spin yesterday and, wow, its like a new car (I wonder if in my 15yrs of ownership this may have been a worsening problem as I don't think its ever run so well - big grin on face). Incidentally, the loud "tappety noise" was a red herring to the main problem - it was a crack in one of the tubular header to cylinder head welds which created a small enough gap to give a metallic sound like tappets !!In conclusion I want to repeat my gratitude to all of you that helped me to get this sorted esp, as above, Russ for all his Forum and PM details, which has saved me huge sums if I had to use a garage and, perhaps the bigger benefit, is that I have learnt loads as well.
Hopefully this may help others equally
Cheers
Ian
- I'd better calm down now
Comment