I have been trying to get my 99 to run better, First it was rich, dirty plugs.But went like a rocket while running A new needle jet and nearly seized it up!. back to the old jet and a 31/2 slide to replace the 3 ,spit backs on pick up but sooty plugs on the move. back to the new jet and raise the needle,better running but still spits back. Then looking at the new jet its marked T , with no air bleeds,thanks carb experts! drill the air bleeds , ,,worse, T may mean two stroke?, different internal shape?. Back to old jet and a 3 slide. ,wonder what it will do tomorrow?. Rich I think. Measured a new 106 which is 107 !!, Think buy 105 jet and size it myself. And make that 31/2 slide into a 3 1/4 which is a size you can't buy.,but richer and will affect the needle height, No fuel injection is this much fun!!.
You must be enjoying yourself too much to spoil it by buying a new one....?
Hi David. Not been terribly impressed with new bits. The carb shows little wear ,so not prepared to give in ---yet. Will be giving it some mileage over the weekend .
hello you say you changed the cut off slides from 3,1/2 to 3 witch makes the carburetor rich now if you had gone to a 4 slide that will make the carburetor run that bit weaker mixture I have the Amal Manuel and its some 140 pages with all types of Amal producs and it tells you all about mixers and how to set up a carburetor right way and even has the setting for the GP and TT carbuertors along with Mono bloc and concentric and pre-monp bloc and all their part numbers , So now the lower the slide number the rich the mixture the high the number the weaker the mixture Yours anna j
Have you done one yet to establish main jet? Have you checked float level? Did mine by drilling 3 holes in a bit of perspex,was far too low. 106 needle jet no air bleeds just the 0.106” hole. Mines one 240 main, 106 needle jet middle notch. 3.5 slide spits back a little when cold
Hi Anna, Over the years I have collected plenty of 376 slides .a whole set,plus a few customised ones. I also have a few carbs including Dellortos ,pumpers and SSI racing ( TT type) .I have recently aquired a brand new Bowden sports carb in its orriginal box with full instructions and spare floats and jets ! can't imagine thats ever going to happen again. Wonder what it was for?. I also have the Amal book , but would like the book for the 1930's onwards. .Hi Peter,I have played with the fuel level and have some machined float valve bodies that give different fuel levels. but the orriginal one works best. I think the 106 should have air bleeds. Where does it say different?.
...a mono lock float extension with glass end plate I have one. It helped with the velo...ven was not running right. (Starvation...)
will send it on if needed.
Hi Jon, A kind offer, Things were running reliably for years, but always a bit rich and dirty ,plugs would soot up ,oil got carboned up a bit too quick. ,but it would ride well. Then I decided to fit some new bits--------. All went downhill from there. Its managing to run rich and weak at the same time. To add to the fog , I was experimenting with increasing the oil feed to the head which always seemed dry and noisy. Its a balancing act ,very easy to get too much oil and find the ignition suffers. I have that sorted now with a customised tank union and a series of tiny adjustments to the tank return flow. What did not help was my local Esso garage where I bought my High grade non ethanol fuel would sometimes cheat and fill the pump tank with EO 15 or 20 ( Carelessly slosh mixed EO5 !!) and that runs very weak in comparison. I have in the past envoked the weights and measures legislation and got a conviction for short supply for a garage and watered down Vodka for a pub !!, but fiddling is now endemic and no one is interested. Going for a run today armed with spare slides .Also need to burn off half a tank of god knows what it is and get some PETROL. (if I can find it).
Try to use Shell V Power- guaranteed 99 RON
Robert,If it is running well but with sooty plugs, have you tried using different plug grades? Maybe a hotter plug will resist sootiness?
Several years ago I had similar problems with a Commando and 650SS.
We had a spark plug representative as a guest speaker at a club night and his answer was exactly that. Modern fuels require a one grade hotter plug. I changed and both bikes now have clean combustion and slightly brown plugs. Can't comment on UK fuels as we have 98 octane ethanol free, 94 E10 and 91which is reputed to be E0 down here.
Still it's a cheap test.
Had my 50 mile run, a stop before a mile to take the tank/saddle off and drop the needle a notch. Runs now as well as a normal 99 could be expected. However thats a major dissapointment as in the past half throttle whisked me up to 80 with plenty to spare ,now although its making all the right noises ,I'm not convinced, the zip has gone. May wait untill I can fill up with the right stuff.Then go for plug chops or a dyno test. Serves me right for running out of petrol and having to fill up with FAKE stuff !!. The tiger has left the tank.
Hi Ian/Alan, I have fine wire plugs one grade hotter but after a Dieseling session and very blue pipes I dare not go hotter. Also noticed a few ally flakes on the plug , Just dodged a bullet there!!. Perhaps a move to the IOM (no eth at all) will bring biking heaven.
Worked on the bike yesterday,after being a bit disgruntled with the lack of zip. Pulled the slide from the monoblock and found the return spring wedged to one side and tight to the body. So probably not getting on the throttle as normal. Must be old age. Grumpy old git.
I thought hot plugs damaged themselves (and might lead to running on...) but don't actually make the engine any hotter. But how many of us start our bikes on soft (hot) plugs to prevent oiling, and put in hard racing plugs designed to run cooler but therefore oil up when the engine cools down? The skill of changing plugs according to usage seems almost to have died out (like the skill of making flint arrow heads!). But of course modern engines don't use oil like they did in olden days, so oiling up can't be such an issue.
My overheated running on was caused by weak mixture on the needle jet (a new 106T ,, whatever the T means) ,Went back to a used 106 ,measured and found to be the least worn ,probably equating to a 1065 +, No spitting back but very sooty plugs and hunts a bit. Will go back a notch on the needle next. I'm getting really quick on taking tank off now . The Gunsons Colourtune shows the pilot needs to be 3+ turns out so the pilot is either too big or fuel level too high. Think I will wait till I get a tank of new Esso before I do anything . That seems to run richer than EO5 .Don't want to have to start all over again.
I notice that a number of suppliers are selling the Amal 106T needle jet ,sometimes described as 106 T style . and purporting that they are for a range of different machines . Looking thro the Amal books it would appear that it was only specified for a couple of odd machines. I dont know what the "T" stands for except that the one I was supplied had no air bleeds .I am suspicious that it is also machined differently on the inside. Does anyone know more?.