I went thru both carbs. I cleaned all the crud out, blew air through every hole. Cleaned out fuel tank, verified good flow throughout all the new hoses into the carbs. New 91 octane zero ethanol fuel. Starts on 1st kick every time now. Idles well. on the test rides, it will not go over 30 mph. It starts cutting out. I let off of the throttle, and all is good again. Is this a timing issue? If so, will someone educate me on how to adjust it? Any other suggestions on what could be causing this?
Apart from a brief experiment with Nippon Denso in one Honda in the 1980's, I've run NGK's exclusively in all my bikes since about 1978 or 1979. Never a problem; however, I do make sure I buy from a reputable dealer.If you are running NGK plugs then don't,
Very difficult to buy verifiably-good Zeners.replace the zener diode
First establish whether it's carburation or electrics (ignition).How does one check ignition
I have found that a ‘jumping’ tacho is more likely to be a cable fault than a tacho head fault, it might be worth inspecting and lubricating the drive cable first, the square drive end should not rounded off.the tach is bad (jumps all over the place)
Do not worry about the bike setup, just look at the battery, red timing light wire to the + battery terminal, black timing light wire to the - battery terminal.The timing light that I use on my car has a tach built into the back of it. I've never hooked it up to a bike and the positive ground thing I am not clear on.
Good info. Thanks PegI have found that a ‘jumping’ tacho is more likely to be a cable fault than a tacho head fault, it might be worth inspecting and lubricating the drive cable first, the square drive end should not rounded off.
Do not worry about the bike setup, just look at the battery, red timing light wire to the + battery terminal, black timing light wire to the - battery terminal.
If you have points fitted then left ht lead times the left side and right ht lead times the right side, if you have electronic ignition then you only need to set the timing once and can use either ht lead.
The timing marks on the alternator should line up when you rev the engine to 3500 rpm, (not at idle speed)
Some people remove the choke slides altogether, but I believe they seal the cable hole to prevent air being drawn down, other leave the choke in but permanently fix it in the top position but remove the cable.
The carb slides can be held out of sync in two ways, the cable and the throttle stop screw. An easy way to set this is:
1) slacken the cable right off so there is excessive play at the throttle-maybe 1/2" before the cable takes up the slack.
2) First to set the throttle stops—screw out the throttle stop/tickover screws as far as they will go
3) take two pieces of thin wire (thin welding rod is ideal) about 6" long, wedge one under each throttle slide.
4) turn the throttle stop screws in on one carb until you just see the rod twitch, do the same on the other carb. The throttle stop screws are now synced, mark with a sharpie the position screw slot is on each carb.
5) Now to set the cables, very slowly turn the twistgrip while watching both rods, they should move together, if one moves first, adjust the cable on the other carb using the screw adjuster on the other carb to shorten the other cable.
(In your photo I can see one fully down, on the carb top plate) set the adjusters on top of the carbs until the rods ‘twitch’ at the same time. Cables are now synchronised and the locknuts tightened.
6) set the tickover, the throttle stop screws are synchronised but you need to lift the slides so the engine will idle.
When you move one screw, make sure you move the other screw exactly the same amount- as a basic setting screw in each throttle stop 3/4 of a turn, and start the engine-the engine will most likely stall when you let the throttle off, if it does -screw in another 1/4 turn on both screws-try starting the engine again. When you get it to idle, set the tickover speed—the secret to this is move each screw the same amount each time.
7) Go back to the handlebar and adjust the cable slack at the handlebar to 3/16", check at full steering lock each way.
The carbs should be synchronised fairly close, enough for the bike to run quite nicely (once your problem is resolved), you can further fine tune from this point later if you wish.
Note: (I have assumed that the standard throttle cables are fitted, with one cable to the twistgrip, and a splitter box to that has two cables to tha carburettors)
One thing not mentioned- is beacause you inherited the problem, do not assume the previous owner has everything correct- he might have bolted the wrong carbs to your bike—check needles type, clip positions, jet sizes and throttle cutaway number are all correct according to the Triumph manual.
In your photo I can see the fuel filters, these might be blocking flow. To check this:
1) fit the tank and half fill it, put the petrol cap on.
2) remove both drain plugs at the bottom of each float bowl.
3) put a measuring jug underneath
4) open the main fuel tap only, you should get 300ml (1/2 pint UK, or 0.6 pint USA) flow in one minute
5) close the main fuel tap and repeat with the reserve tap.
6) if the flow rate is slow, try again with the petrol cap off the tank-in case the vent hole is blocked.
7) if the flow rate is still slow try again with the in line filters removed.
When you test ride, follow the advice to ascertain basically whether the misfire is carburation or ignition/electrics, something you've so far failed to do despite advice - all the faffing with the carbs. will progress absolutely nowhere towards finding the cause of the misfire if the cause isn't carburation?Wanted the test ride, but too much ice and snow on the roads today.
You don't need to:-tach is bad (jumps all over the place)
I cannot answer your questions about rpm when thing start to go bad.
"If the misfire's at the same twistgrip position in different gears, it's carburation"; the actual rpm is irrelevant but, having changed gear, the tach needle will be "jump[ing] all over" a different area of the tach? Changing to a different gear again will have the tach needle in another area of the tach?As "Peg" advised, mark (dab of paint? Magic marker?) the throttle housing where you can see it when riding the bike; mark the grip beside the throttle housing corresponding to 1/4, 1/2, 3/4 and WOT.
... test ride. If it misfires, note twistgrip position, gear and rpm; change gear and note twistgrip position and rpm.
As "Peg" posted, Red wire to battery +ve, Black wire to battery -ve.The timing light that I use on my car has a tach built into the back of it.
which plug wire do I clip to? Do the other leads go to red and black battery terminals?