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Post Info TOPIC: Carb issues when uncorcking


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Carb issues when uncorcking
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Hi, mates;

I got my "new" bike, TTR 250 blue / 2003 a few weeks ago. I couldn´t test her as my arm was injuried, but seemed to work nicely (1000 m high area).

On the while, I´ve read about how to uncorck her (thanks to all the mates dropping so valueable info !!)

 

When I´ve been able to hold an screwdriver, I started the process.

First I checked the screw under the seat. Seeemed to be high enough.

Took the header off and checked it was empty.

Cleaned airfilter.

Took the snorkle off and opened the air filter box as I´m not doing deep water crossings (no more than 2 ft ¿)

Rejetted as read here (140/52,5)

 

I´m living at sea level.

.... and gone for a test ride. The bike seems to have a good potential, BUT: Its OK at low and low to medium revs. Its also OK at high revs. But when passing from low/medium to midium revs, has a clear low in regimen and power.

 

I´ve asked my confidence expert and told me there´s a lack of gas, so need to rise the needle one position. It sounded nice to me and reopened the carb.

When trying to unscrew the "slide arm retaining screw" I realized it was too tight. When insistes, the head started to lose the scredriver´s step and the screwdriver started to twist lose (f***K !!)

Now I would like:

- Any alternative idea or solution to the performance lack at 1/3 revs¿ (If I don´t need to touch the needle, then solved problem !)

- Any "non-dramatic" way to loose the retaining screw¿ 

 

Further steps; Shorty header, 13/47 or 13/49 sprockets, fmf silencer (last, owed to price!)

 

Any advise or suggest welcomed !!  (Thanks in advance from the Basque Country !!)

 



-- Edited by Indigo on Monday 22nd of April 2019 07:24:42 PM

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I´ve finaly been able to home made a short header. Revs raise is better but still a short gap.

I´ve been able to raise needle one position and the raise in revs is sweet and contundent. Great !

Now the engine goes nice, the raise in revs is uniform and... CONTUNDENT.

I´ve gone for a short ride today. 15 km/10 miles, sunny and dry, but no more than a few meters flat.

I´ve gone to my old enduro area which I know well... This is not a light bike as my last 2 strokes... but the torque is huge and the climbing capability is just... INCREDIBLE !!

I´m really happy.

I´ve ordered 13/52 sprockets and earning for a new silencer and probably a lighter battery.... Xtsms list ¿!

Great bike !!



-- Edited by Indigo on Friday 11th of October 2019 05:45:23 PM

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Great!
I run 13 52 and its super short is great for tight riding in lower gears, but flat out about 107 - 110 kph. And climbs hills even better. These 250cc 4 strokes find traction they dont wheelspin like 2 strokes and big modern 4 strokes. Lots recommend 13 48 for a slightly taller gearing with more comfortable cruising.
As for jetting check your spark plug condition it should tell you how its running, plenty of information online.biggrin



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Yes, thanks, this foro has been a bible to me !!!

The info for the uncorcking was definitive. Once uncorcked I started thinking further improvements. Silencer, etc. The final bike is a very nice toy !! Not a killer, but enough.

Now plenty of mud I´m enjoying her a lot. 13/52 is Ok but I think a 48 would also work nicely. I started with 45 but was summer. Even though the bike could handle it.
I like the 52 cause let use de second gear most of the time. Perfect for climbing on mud (very common, here).

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