A forum for owners of Yamaha TTR250 trail and enduro bikes!

The exhaust was literally red hot?

Ether wrote:

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The exhaust was literally red hot?

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 Yeah header??? Pipe glows.

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Look i'm sorry, but i'm still having an issue with this.
Fired bike up in shed (cold). Idle screw adjusted low. Revs low..
Took it for a quick squirt around the block 500meters+. Pull up at shed.... idles high..
I am confused as to why it idles low on start, i let it warm up for a couple of minutes....
Then 3-5 minutes later. Idles high without touching anything.
I might just set idle screw back to factory settings.
Z
Thinking maybe it's the throttle cable??? Will wd40 it and see. So strange.

-- Edited by z1g on Friday 18th of May 2018 02:22:54 PM

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Thanks ttrfan, checking it out.
Just adding a pic of it warming up, after 1-2 minutes. Lights off to see the glow.
Cheers

Because i a new, just wondering out loud, if this is normal.please excuse my ignorance.

Just to be clear, this is ideling at a low rev, (started with choke out for 3 seconds then choke in) idleing for about 2 minutes. Have not ridden it since last post. But that look super hot to me.

-- Edited by z1g on Saturday 19th of May 2018 12:34:45 PM

2nd edit: took it for a ride, idles are XYZ revs say 500 just for a number, 1 minute of riding, pull in clutch, revs at 1500. (Don't have a tacho to tell, just by ear).

It's higher. Feels like 4k when pulling clutch in, to go through intersections.?????? Way,way  higher than idle.

 

-- Edited by z1g on Saturday 19th of May 2018 01:41:39 PM

-- Edited by z1g on Saturday 19th of May 2018 01:46:24 PM

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Just came across this, so may not be too hot after all. https://www.xt660.com/showthread.php?p=211566

 

 

Something is not right mix wise that pipe should never get that hot on tick over maybe at full thrash after 10 minutes you might get a bit of colour to it if you stop and look quick in the dark. I would go with the mix being to lean as the problem so its under fuelled or a air leak as has been said. I have some pics hear somewhere of my old Gpz Drag Bike with the headers red/yellow and the pipe from the collector back to the can covered in Ice when we had it on a rolling road one time with 175Bhp of Nitrous oxide pushing the motor past the 300 Bhp mark will see if I can find them and post them up

Pug

How do i check for carb leaks???
Or fuel mixture.

I think i'll take a wd40 the throttle cable first??? Feels like the throttle rolls on and off as it should...but obs something is not right
Sorry to be a knob.

-- Edited by z1g on Sunday 20th of May 2018 12:36:10 PM

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cheers pug,

heres what it sounds like from my end.
I try and fire it up NO choke.
then I put choke on, for about 3 seconds? it revs higher,
turn choke off,
and it now revs at a normal speed.

if it sounds different, thats because I was recording the exhaust, and the engine. so walking around it.

ttr250 startuo (29seconds)

vocaroo.com/i/s0ov88g6D1o3

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What about when you rev bike stationary, does it return to idle then? Cannot hear vocaroo.
mike

Micccki,
When i pulled carb off, i did have some trouble putting it back on, re:linkages i don't feel they (2) cables were set back to original settings.
Takes a while for sound clip to load, give it 30 seconds. Working my end.....(on tablet device)
Now that it's been mentioned, when choke is on, seems to over rev (after listening to it) more than what it should. Sometimes i do not have to use choke.??? Tonight is cold, so.....
i prob stuffed up something after doing a clean on carb.
all ears.
will be trying all suggestions.
thank you

Z

Does the audio clip work for others??? Cold start.

-- Edited by z1g on Sunday 20th of May 2018 02:33:16 PM

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Heard it now. sounds ok to me.

Ether wrote:

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That glowing is a bad sign after just 2 minutes. Can you get temps for the exhaust when it's red hot? Have you checked valve clearances? Also what does the spark plug look like?

If it were mine i'd change the intake manifold in case it's leaking. They're not expensive. Mine was leaking but it has the old ****ty manifold which your bike probably doesn't. 

-- Edited by Ether on Sunday 20th of May 2018 07:04:18 PM

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I'll buy a temp gun, as its a bit of kit i think i should have. Plus cheap enough to have.

Brand new plug put in, can pull it out and check. No never looked at anything engine wise. Has less than 5k on clock since 2005 (if you believe the story, which currently i do, but i'm somewhat of a trusting person).

Seems to run fine, just buggered why it over revs after a short squirt, never over revs when just idling.

Bit busy this week, but will start to test things this weekend as others have suggested.

Again many thanks for all opinions.

First air cooled bike i have owned since the mid 80's :) so no experince with them really. I just noticed how hot it looked and wondered if that was normal. Seems like it's not.

Yeah i would back myself up and say, it became that hot after a couple-3 minutes, may have given it a rev or two (don't remember to be honest). But was not ridden when pic was taken.

Have not ridden it since last post, but i have listened to my audio clip a few times. I'd say that when i ride for 1km and pull up at my garage, it rev's like it does in the audio clip (when choke is put on) aka high. SO TO ME it seems like after a ride, it revs (high) like the choke is on?? 7sec mark in audio clip

Audio clip

Key is on

Fuel is on. 

2-5 seconds first click is red button on bars

Then hit starter button, does not fire up

5 seconds 2nd click is the choke being swithed on, and hit the starter again, 10 seconds when the revs die, choke has been switched off.

 

-- Edited by z1g on Monday 21st of May 2018 01:04:13 PM

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Hi guys,
Hoping i am doing things correctly.
Pulled of plastics.
started it up. (With choke)
idled just as normal. Waited a couple of minutes
Sprayed wd40 on intake, and the outtake manifolds? Whatever the back of the carb is called to airbox
No idle difference, could not see any bubbles or anything, i just assumed that an airleak would show bubbles or sucking up wd40.

Visually looks like both are on correctly??? 

Again sorry, i'm new here.
i'll rip the carb off tomorrow, as most seem to indicate air leak, i bought some new allen key screws for carb, as one got stripped. Last time it was off.
will also adjust the internal screw ttrfan mentions in above post(seperate thread), will also check acc pump diaphram.

Have not ridden since last post.

also bought a temp gun(ebay)

Even just tonight, fireing it up, looked like header pipes got hot, idleing fine i think. Not to high. But i really do not know enough.
again thankyou all for helping
best
z

 

Edit added pic of allen key screws (hope these are ok, fit etc.)

M4x10mm?????

 

-- Edited by z1g on Saturday 26th of May 2018 11:37:31 AM

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Cheers pug.
Yeah, i understand that. Hard to diagnose especially when i have very limited knowledge.

I *have a cold*, so everything hurts.

I am about to take the carb off, i have only done this once before. So i am sure i did something wrong when putting it back on.

i just observed that the throttle cables have play in them.
I think my idle screw is turned in as far as it can go.

when i use the throttle it moves,
When i release throttle it moves back.

If i do a revese throttle aka pushing throttle to the all the way off position, i get a cable that i can almost manually take off the "throttle track"

MY QUESTION to all is, could this be causing my high revving whilst riding situation EVEN through during idle it's fine.

Sorry for dark pics,
Just hoping to solve this problem.

I will be pulling the carb off to replace the screws, just not tonight. Massive headache..... #manflu
Cheers

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Just adding in case anybody reads this.

Took it for a quick squirt, about 700meters.
Seems to still rev higher than idle when i get back to the garage.

The only thing, i have done is, adjusted the throttle cables.
One thing that worries me, is the idle screw (or what i call the idle screw) this is out as far as it goes , then about 2 turns in. That was a major change from previously.

When i pulled into garage. It was revving higher that what it idled at when i took off for a ride, so slightly adjust that idle screw to a lower rev.

I also wd40 it, again, whilst idleing to see if then rev's went up. It did not appear to change at all.

BUT at this stage NOWHERE near what it was after a ride in my previous posts, also did not really notice high revving when i pulled clutch in..
Still early to know one way or the other.

still worried about the hot pipes though. On a side note: when i switched it off, it popped out the exhaust.??????
cheers
z

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Have you taken your choke plunger out to check the end hasnt parted company with the main choke end. it would loosen up when it warms up.
You hardly use the choke to start from cold, which points in that direction....?

My airscrew ( starred one under the inlet of carb ) is 2 turns out, give or take 1/8 of a turn, i painted a red spot on it when shut , so i could keep check on how far round it was , ( should have gone to specsavers..! ) as its upside down and tight to get to with my podgy fingers. mine is a 50 slow and 147.5 main

The little brass bit you found goes in the join of the carb bowl edge for the pumper diaphram to work,as i recall..? so if thats not in it will draw air . im sure you would have seen it was missing and found its home.

I thought it sounded like the screw in the top lever under the cover, check theres no movement in the arm even though its tight ,as a little play there, might add to your over revving.

My Dommie was like that and i changed all the tubes and jets for new, and get the use out of having a rebuilt carb to use. it makes quite a difference, sharpens it up.

but with low milage there wouldnt be any wear .....? did it look like someones been in there already, maybe theyve changed the jets to different jets , easily done...
we all like to get more out of them , try some new jets and tubes , and check your fuel filters , as they might be clogged up with grime , it builds up , it comes with a new needle jet mine was clogged when i took it off.

Im not a mechanic , but ive taken the ttr carb off about 60 times,,,,so i got to know it quite well after a while... My inlet manifold rubber had seperated from the metal also , didnt see it, and any slight gap there will mass up your settings, and not be constant. but mines a 94 so its had some use.

hope this helps

Many thanks kevred.
Will be doing further investigations.

This started out as high reving whilst riding, now seems to do more with HIGH temp's.
It was really only an after thought that the pipe was hot. last night 10 min ride, outside temp must have been 4-6c but when i got back to garage, pipe was red hot.
Wish i paid more attention during mechanics @ tech high school now.
I think i will rip the carb off again (3rd time for me). I think i am the only one that has done this since 2005.

I have not removed the float, as i am lead to belive this is a bit delicate? Given the state of the carb when i cleaned last, i assume it's very dirty under the float, so may be my next attempt.

Sorry for sounding like a douche, but i was going to remove the choke assembly, but spanners did not appear to have enough clearance, will double check that once it's off again. I was not really focusing on it.


Thank you for you're input much appreciated (as are all comments/suggestions).

Hopefully get this sorted.

Other than this prob, i LOVE THIS BIKE.

-- Edited by z1g on Thursday 7th of June 2018 10:43:39 AM

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Hi all.
Since my last post all i have done is.
Let it idle for 5 mins. (Timed)
Pipe did not get red hot. Hot to touch mind you
Cooled down for an hour or two. Then
Taken it for a 5 min ride on return home (pipe was not red hot)
I rang a couple of people re: this issue as this annoys me greatly.
Best they can explain, was since bike has been sitting for 3-4 years before i have bought it, they seem to think carbon in pipe was just getting burnt off.
Meaning that last 50km, was just burning off crap that was built up over the years.

I have NFI. But can say that last two start up's have not gotten the pipe as hot as what it was when i posted it originally. (See pic)
i have done the same as what i had done when i post pic of hot pipe. Now is different. Only difference is tighten throttle cable and idle screw was adjusted????

not sure what to believe other than it seems i am good to go now.
if this comes back will start a new thread.
Thank you to all that helped. Really appreciate it.
beers all round.
z

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Nope I have to do the same myself.