does this work? https://i.imgur.com/tPVjAaC.gifv i went looking for a video i made years ago of mixture reversion on a machine with open pipes. the fog in front of the air horns is a cloud of rich fuel mixture. the air gets drawn through the carb and is charged with fuel, then pushed out and charged agsin as it goes by the jets, then gets sucked back in and is charged a third time. hence the overrich mixture. imgur didnt do sound back tben. sometimes the slipstream blows it away, and you may be running a variety of throttle positions at that rpm, so its v hard to correct with jetting.
Here’s pic - those look like baffles right? In any case, the pipes are a bit banged up so could use some new silencers and exhaust rosette things.
yes. those would be baffled mufflers. you have a plate welded in separating the inside into two chambers, then six tubes leading out of that chamber to the outside. so the exhaust gases go into the first chamber and expand, then bounce around until they find their way out the tubes. that sort of makes the sound quieter. there's lots of pipe options available to you for new ones. but this doesn't answer the question of why your machine is hesitant in the midrange. so what's on your list now is a check to see if everything is adjusted correctly. when was the last time your machine had a general tune up?
[QUOTE="speedrattle, post: 554144, member: 20531]When was the last time your machine had a general tune up?[/QUOTE] It’s been sat in a garage for a year or two and before that wasn’t ridden much in the past 20 years. Right before I put it away, I took it to a mechanic who works on old bikes and they did a full service, fork rebuild etc but recommend fitting a new carb as the original one was finished. I know the engine has had a full rebuild about ten years ago and has probably only done 50 miles. When it was running it sounded great. Idled and ran well. No idea if timing is ok but would love a setup that starts on first kick as when it stopped running I couldn’t start it even with a rebuilt carb I’ve now fitted a new Amal Premier Carb, drained the tank and added fresh fuel. I’ve also renewed all wiring and returned a missing heat sink plus a new battery / plugs. I think when I fire it up next I’m hoping it’ll be good to go and I just need to ride it more.
if it runs well, then thats all you need. you havent said whether it has points or an electronic ignition. an inexpensive boyer or pazon surefire will be a vast improvement over the old points setup in terms of maintenance. i've run a boyer in one T120 for over 30 years, and its still a one-kick start when the rest of the system is working. i have another boyeyrin a norton and a pazon in a BSA that are the same way. you may find that just raising or lowering the needle clip in the new amal carb is all you need to do to fine-tune your midrange problem. the premiers are excellent carbs, but there is no such thing as factory correct jetting, if youre picky.
Any help with these lads? I have an idea what the answers are, new to spannering on old bikes just don’t want to make any mistakes and don’t have a workshop manual.
4 is good cold as 5h is warm/max, switch with terminal is oil pressure switch and dome item is PRV pressure relief valve, gearbox oil goes in the other side through gearbox end cover, you will see a cap just the same as one in pic that is for primary oil and a new washer on the oil drain plug and gearbox cam plate tensioner will cure drips.
Cheers pal. All clear on sorting the leak. Do I need the OPS working then? There’s no oil fill cap anywhere on the gear side, is it lurking under the casing? On main oil level - so it’s well below even the ‘L’ - means it’s crazy low?
There should be a red warning light on the headlight shell that connects to the oil switch, it could be that you have an early cover that has no filler as early engines had the filler on top of the box. Pic of outer cover on later bikes like your should have.
As in my first pic with the bung removed you can see the hole for filling box, your pic has the bung (round item with slot) just above kickstart.
you ve got an o lder mark 3 boyer bransden electronic ignition in there too. ive got a couple of those. they work very well. http://www.boyerbransden.com/productinfo.html the boyer transistor box is designed to work with 6-volt coils wired in series to give 12-volts. what do the coils look like on your machine? are they marked 6 or 12 volts or nothing? if theyre 12-volt might explain the midrange hesitation.
I’ll check this out as I’ve renewed the battery area wiring (hello positive Earth) and was thinking to fit new Pazon coils.
if you have a VOM you can measure across the coil primary terminals to see what you have. boyer specs say that total resistance of the two coils in series should be at least 3.5 ohms. volts = amps x ohms i run two dynatek coils of 2.2 ohms each on one machine. 4.4 ohms in series, so the amps are 2.72, well below the 5 amp maximum the specs say not to exceed.
Hi all. Despite spending ages on phone and email with with suppliers, they can't seem to tell me what parts I need for a simple oil / gear swap. I'm basically after any replacement washer I need for the drain plugs, filters etc. As I understand it, there is: 1 for the engine 1 for the gearbox 1 for the oil tank. That's 3 washers / plugs. Can anyone (@darkman) point out on the attached images which numbers these are? And whatever else you advise to replace? As always, much appreciated! Last bit sorting before a fire-up.
Copper is best and i use Champion N3C plugs, number for filter is 82-5694 and loads for sale online or dealers. sent PM
Hi all. any idea how to get the chain off so I can get the wheel off? just a case of loosening the tensioners and slipping it off the sprocket?
