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Total Likes: 6
Original Post (Thread Starter)
#811129 06/01/2020 10:25 PM
by splash
After the recent rebuild I don't feel I technically made it out of the gate just yet. Some of these symptoms are new and some have been going on from after rebuild.

1. Idle is oscillating to the point of engine dying to high RPMs when coming to a stop or clutch is pulled in for a turn.
2, Sometimes during shut down (with ignition key) it will shut down evenly then burp a few times after as if it is running backwards for a stroke or two.
3. Right around 3,000-4,000 RPMs the bike vibrates heavy. It's very noticeable on the footrest pegs. I am subconsciously forced to shift here.
4, A random bing as if something is loose somewhere. I noticed this happens more often when a female is on the back. If I had to take a wild guess, It sounds like a clutch plate or two is being slammed into the clutch basket. It doesn't do this when shifting gears though as I would expect it.

I also believe it's burning more fuel but I can't tell because I need a speedo gear box to work the mileage.

Items I thought about replacing to resolve symptoms are:
1. Intake manifold gaskets (3)
2. Ignition switch
3. New coils? (worried)
4. No idea about #4. (worried)

Could 2 and 3 be related?
Liked Replies
by JubeePrince
Originally Posted by splash
Points. IDK about cleaning out jet with #78 drill bit. PORTS? I have no idea. I don't think throttle sticking on the slide or cable.

Read this:

Then read it again.


1 member likes this
by dave jones
dave jones
Good info from the others, as usual.

I had trouble with too high rpms sometimes whencoming to a stop. It was just the cable and all good when replaced.

When I first had the bike it did the thing where you turn off the ignition and the engine runs on a bit like yours. This was caused by running miles too rich, causing carbon build up on the pistons, parts of which can glow red and keep the engine going a bit. Can also be caused by overheating or wrong plugs but as you say yours is using a lot of fuel so it could be the former. Also retarded ignition causes sooting but I don't think as much as rich running.

The odd bit of light intermittent noise. A sort of light clonk. - My bike does this a bit at idle and I think it is because the tangs and the grooves in the clutch have got loads of clearance. I don't notice this at any other engine speed, however. They are so bad that I change the oil in there more often because The last time I looked in there (quite a long time ago) there were traces of metal particles at the end of the grooves. Loose rotor was a suspect but not in my case.I have a whole new clutch and chain in my spares but am waiting for some definite slipping.

My bike vibrates more when the cylinders aren't tuned together ( points can be timed separately) or if the points are dirty.

1 member likes this
by TR7RVMan
Hi Splash, #4, a few things come to mind.
Verify primary chain tension is good. Loose can hit case.
Verify rear chain tension is good. Loose cam hit guard.
Verify left rear motor mount plate has nuts to outside, & also the chain is not hitting blot head from too thick of head. This is the upper bolt. Chain runs near it.
The cush hub makes a clack sound when rubbers go bad. Backing off throttle, then rolling it back on under certain load & rpm.

1,2,3 could all be related. Don’t buy anything until you do some testing.

Does bike die or want to die at steady speeds?

After you verify head torque, cable adjustment, timing etc. try to warm bike at least 10 miles. Set idle rpm & air mixture.

Mark air screw. Turn in gently until it bottoms. How many turns? Main jet & needle clip position are probably not into play yet. We’ll go after those later.

Have you taken carb bowl of yet? What type of float? All plastic? Or black solid plastic with metal fulcrum/needle holder? What is float needle made of? All plastic, brass w/rubber tip, aluminum w/rubber tip?

What ignition system? What spark plugs?

What is air filter housing? Stock or?? What is filter element made of? Paper, foam, wire gauze?

Vibration is hard one. All bolts must be tight. Cross brace between mufflers matter.
I don’t recall rods & pistons. Which did you get. Motor tuning problems can contribute. Do this last. Does it vibrate worse now than before?
1 member likes this
by gavin eisler
gavin eisler
You probably killed it from fuel starvation.
Starting from scratch,
Screw the idle mix/ pilot air screw in gently, once home back it out / unscrew one whole turn and a quarter, 360 + 90, that should get it running again, fine tune when warm.
1 member likes this
by reverb
Those symptoms look like fuel starvation as Gavin is saying. If your float level is good; then check the other usual suspects in the carburetor.
By the way regarding vibration; depends on the engine; but my 48 only start to vibrate when I rev too high for the normal speed of those times if not is good.
The same for my newer 79; when I crank it to the normal high speed of this time starts to vibrate more (at more than 140 km/h)
With the lower gears you could accelerate to 5000RPM (between changing gears) with your bike without any problem but possible that you find vibration if you are trying to ride at 4000 in first gear to say something.
1 member likes this
by HawaiianTiger
We ship stuff back and forth between the islands via a company called Young Brothers. It's not expensive. I think you could ship a bike for 150$ last time I checked. In fact, before all this virus nonsense, the bike clubs routinely rented containers and shipped a whole fleet of bikes between the islands on holiday weekends for rides. The Big Island is a favorite because, well, it's big. You get some serious long distance riding in there just going from Kona to Hilo.
On Memorial Day, or Labor Day, and Thanksgiving, the island here rumbles with the sound of 300 or even more Harleys cruising two by two at 50mph. A lot of them will be from other islands.
I stopped going on these rides after a nasty incident where some people got killed during a ride. And I can say that it's not very comfortable riding in the middle of a pack of Harleys, many with open pipes, when you're riding classic British iron. For example, you couldn't pick a worse speed than 50mph on my Norton. It's between gears and my bike just hates it.
And Splash, if you ever get over here, we'll ride even if you don't bring your bike. I have spares....but if you do, I never met a Triumph I couldn't improve rather quickly.

PS A few years ago, there was a ferry company started, but it didn't last very long. The locals nixed the idea. It would have been great for inter-island hops with vehicles, but not so good for car thieves from Oahu and the drug trade.
1 member likes this
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