MXR problems

Kic · Post by **Kic** » Mon Oct 22, 2007 10:05 pm

first of all, hi to all! I`m new on the forum.

I bought the MXR in totally messed up state... then restored it.

new paint job, tires, brakes ignition, bearings, gaskets..etc.

The problem i`m having is with the idling...

When i pull the choke it works fine but without the choke it stalls and it`s impossible to drive below 5000rpm.. over that point the bike runs fine.

The carb is cleaned and inspected, new air filter fitted, new spark plug, coil, stator... i don`t know what else to check...

could someone tell me what are the stock sizes of the jets and is the PHBH 28 MD original carburator on the MXR

TNX

hahne · Post by **hahne** » Tue Oct 23, 2007 7:49 am

I think; it`s the carburator!! Clean it by Ultrasound!! ... or take a new one. Bye Gottfried

gileraXR1 · Post by **gileraXR1** » Tue Oct 23, 2007 8:17 am

Hi!
Yes Gottfried have reason, I think could be minimum circuit (idling circuit).
You can take a part carburetor and transport it in a small basin with fuel or acetone... and re-clean it.....

But you must be very careful! Acetone melts plastics and rubber parts.....

About stock sizes of the jets in PHBH 28 MD original carburator (for MXR), I'll teel it in the afternoon!

Have a nice day!

Ciao

Marco

hahne · Post by **hahne** » Tue Oct 23, 2007 8:49 am

Or take citrid acid, but be carefully! Bye Gottfried

gileraXR1 · Post by **gileraXR1** » Tue Oct 23, 2007 2:17 pm

Hi Kic!

Here technical data of carburetor, directly from Gilera MX1/MXR 125 workshop manual:

- fuel N.O.= or > 96 (octane numbers)
- carburetor Dell'Orto PHBH 28MD
- diameter 28 mm
- maximum jet 135
- minimum jet 48
- starter jet 65
- conical pin X40/3rd position
- sprayer 264 DG
- throttle valve 50

Good luck!

Ciao

Marco

Kic · Post by **Kic** » Tue Oct 23, 2007 3:15 pm

thank you!

The specs. are ok but there is still no improvement

is like there is low air in the mixture

I tried a different carb... the idle was ok but i`t wont rev properly

hahne · Post by **hahne** » Tue Oct 23, 2007 3:19 pm

Othersides: I have a lot of new 28 mm carbs here on store!! Bye Gottfried

gileraXR1 · Post by **gileraXR1** » Tue Oct 23, 2007 4:54 pm

Kic wrote:thank you!

The specs. are ok but there is still no improvement

is like there is low air in the mixture

I tried a different carb... the idle was ok but i`t wont rev properly

Well.... now I tell you what's the problem of my XR1:

- engine suck air from some place or part (and now I know from where).....!

- at minimum of rpm it'a all ok...... (1500-1600 rpm)
- when you open throttle a little (2000-3000 rpm)... there is this sound: BOOOOOO.... BOOOOO

- and when engine return to minimum rpm it remain quite accelerated for some seconds....
- after this n° of rpm all it appears ok (4000-7000 rpm)...

If this it's your exact problem.... well... I think that it's possible that you must to take a part all engine and.... change gasket set of crankcase!

However look at:
- air conduct (from air box to carburetor), if it's well sealed....
- mixture collector (from carburetor to reed petals group), if it's well sealed too.....

Good luck!

Ciao

Marco

Kic · Post by **Kic** » Tue Oct 23, 2007 5:09 pm

believe ti or not i cheked all of those things...

i fixed the choke to bi opened half way all the time and now it`s ok...

Another problem... anyone has a motoplat black ignition coil

mine died a few moments ago

gileraXR1 · Post by **gileraXR1** » Tue Oct 23, 2007 6:17 pm

Kic wrote:Another problem... anyone has a motoplat black ignition coil

mine died a few moments ago

Sorry, actually... no one!

Ciao

Marco

Kic · Post by **Kic** » Tue Oct 23, 2007 6:45 pm

those ignitions are very rare aren't they? I spent 3 months tracing the stator and flywheel.

I managed to burn one original black motoplat and one universal ignition coil

can`t figure out what went wrong

I think i will sell the god dam thing.. i spent a fortune on it trying to make it work

gileraXR1 · Post by **gileraXR1** » Wed Oct 24, 2007 10:31 am

Kic wrote:those ignitions are very rare aren't they? I spent 3 months tracing the stator and flywheel.

I managed to burn one original black motoplat and one universal ignition coil

can`t figure out what went wrong

I think i will sell the god dam thing.. i spent a fortune on it trying to make it work

Hi Kic!
If you want I can try to find some things you are looking for, here in Italy.
If you want.... please tell about it!
Have a nice day.

Ciao

Marco

hahne · Post by **hahne** » Wed Oct 24, 2007 10:57 am

Othersides; I have a lot on store! Bye Gottfried

gileraXR1 · Post by **gileraXR1** » Wed Oct 24, 2007 1:43 pm

hahne wrote:Othersides; I have a lot on store! Bye Gottfried

That's right!

Ciao Gothfried!

Marco

Kic · Post by **Kic** » Wed Oct 24, 2007 4:09 pm

i`m interested in the price of the origina coil.. because the last one i bought cost 40€, it was an universal coil and it worked well