Will idle, but will not rev up

[Ant132]

Hi all, ive just put a new engine in my Triumph Trident, however, now that its up and running it refuses to rev. It will generally idle fine but will not rev up past about 1750/2000 rpm without cutting out.

Any idea on what to look at?

Thanks, Ant
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1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[oldbiker]

Hard to diagnose from so far away,

cutting out through weakness?
I would check for fuel starvation first, Is the fuel line blocked or kinked, tank breather clear?

Then check for carb problems such as crap in the filters or a loose slide needle.
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Cutting out due to richness?
Check the chokes are not staying on.
Check that all the jets are secure, has a main jet come loose?
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It`s all powerfull white mans magic
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[The Artist]

Check all passageways in carb.

Most likely something is blocked and only the idle circuit it working.

[temeluchus]

[Alexio]

Last time this happened to me I just could not figure it out. Idles fine, but dies as soon as you tough the throttle. Then I looked at the fuel gauge and realised I was empty Switched to my reserve tank and all was well. It's just amazing that I got my bike home with no problems and used up exactly the right amount of fuel to empty my tank without it dying.

Anyway, it's sure to be a fuel / carb problem as suggested above.
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will never give up his CG. I look at my fuel gauge more as a progress bar than a fuel gauge.
G: With my GSXR I do often effectively use it as a scooter with a clutch in town.
ms51ves3: why does it need 500 miles? Are you teaching it how to be a piston?

[Ant132]

Thanks for the replies

I had the carbs back off yesterday and found them spotless, cleaned them anyway but didnt find any blocked jets or anything.

I put them back on and made sure the airbox and inlet rubbers were tight and on properly. The fuel lines are all clear and routed OK with no kinks or snags.

It works 'ok' on the choke but seems to rev up very quickly. As in, the slightest bit of choke will make the revs shoot up, but the throttle wont.

Ignition rotor was supplied with the engine. Also, i definately have enough fuel. Im running it on reserve to make sure but ive also tried it on prime - no difference.

As i say ive already cleaned them again but i havent tried it, due to there now being a dodgy wire or something to the solenoid. All im getting is the occasional clicking. But i dont get anything unless i wiggle the wires about. One thing after another..

Thanks all, Ant
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1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[Alexio]

Could be weird throttle linkage, or a weird electrical problem them where every time the throttle is opened, it shorts two wires somewhere and it all just dies That would be unlucky indeed.
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will never give up his CG. I look at my fuel gauge more as a progress bar than a fuel gauge.
G: With my GSXR I do often effectively use it as a scooter with a clutch in town.
ms51ves3: why does it need 500 miles? Are you teaching it how to be a piston?

[Ant132]

Right, sorted that dodgy wire. Turns over now.

Bad news is that the carb job yesterday hasnt done alot of good, the good news is that it seems to rev now but the bad news is it wont idle so well and now when you rev it the revs stick on. Say, you rev to 3-4 k and loosen the throttle - the revs stay there.

Theres quite a bit of white smoke from the exhausts too, and it also leaks fuel on prime . I reckon the clean up is not enough, i think i may need actual new float needles and not just cleaned ones. What you think?

If not, next step electrics then
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1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[oldbiker]

leaking fuel on prime?

could be crap in the float valve,
or the float needle could be worn possible if the bike is say 8 or more years old.
it`s also possible that you may have altered the float height.

carb sticking?

Sounds like the carb cable has got twisted or caught up.

(I`m sure you will get there in the end)
____________________
It`s all powerfull white mans magic
https://i897.photobucket.com/albums/ac178/tzrsteve/album%201/035.jpg