My CR is almost fixed...

[helio]

Hi guys,

I have posted some questions about to fix my CR 125...For members that are remembered about my problem here I am with the potential solution...
Just to refresh our minds:

- Clean air filter and air boot, NGK B8ES brown, no water in carb, crankshaft ok, rod perfect, new top end, carb vent hoses ok, fresh gas, mix 32:1 Castrol TTS, compression ok, idle perfect...

Current jetting:
Pilot 50
Main 173
2 rd clip
AS set for better response

The bike has a great response from idle to wide open in the STAND...and after to bore you with a lot of questions I have detected that my bike only bogs and begin run erratic after riding in wide open mod for 20 or more seconds and then it stops...and start after 4 or 5 kicks...Moral of the story ? My mechanic re jetted it with dirt in air filter (he confessed me...) in a track.(BTW I have been sick in home)
I know that a dirty filter will rich the jetting and will mess the plug reading...
- Can rider weight makes also a huge difference regarding the jetting ? I have more 20 kilos than him.

BTW I am going to try a large main.

THANKS ALL FOR YOUR TIME.

 

[_j0kA_]

Hi!


Let's start with what I know for sure..

A riders mass won't affect the jetting of a bike.. A dirty airfilter MIGHT..


And let's take a stab at what I don't know..

I would suggest that if your bike is bogging after running wide open for long period of time, then you would have to go down on the main jet because if it is lean there won't be an excess of carbon ( oil, etc.. ) build up on the piston to be burned off.. If you go larger, then it will be shooting more fuel into onto the piston and causing it to bog, right??

Don't use the advice that I don't know untill you ask some other people.. I might be totally wrong, and I wouldn't want to mess your bike up.. Remember that if you go too LEAN, then you could seize your engine..

Good luck!

Dan

 

[helio]

If the bike after wide open period bogs and stop(and start again after 4 or 5 kicks... it´s the time to load fuel again in carb).
It seems to be lack of fuel in carb so I am thinking to go one size up in main jet...
I know a size up or down does not seize an engine...But is it possible to make this sympton ?

More opinions pls.

 

[_j0kA_]

Hmmm...


Take your carb apart and clean all of the jets with contact or carb cleaner..

Does the bike always start after it bogs? It sounds like it's going to foul, so that would mean your jetting is too rich and to fix that you would have to go down

Are you sure that your plug is tan colored?? If it is, then the only thing that I can think of is that your jets are clogged..

If I think of something else, I will reply..

Dan

 

[_j0kA_]

Hi!

I asked a friend what he thought it could be and he suggested that you check your float level, and maybe go up one size on your main..

Your bike is basically cutting off the fuel at high RPMs..


Dan

 

[helio]

Maybe the term bogs should not be the most descriptive of this symptom...The plug is colored and not wet, I am going try to describe what I feel.

- Wide open running perfect and after a long period it seems to loose power...Boooohhhhhhhhhh as lack of fuel...then re starts and seems be suffocated for a bit...After that no problem still a long period of wide open.

All carb parts were cleaned.

 

[_j0kA_]

Ohhhh!!

I read in one of my magazines before that when you hear the 'boooowwah' sound then that means you are usually running too lean ( I think.. It might be the other way around!! )
Go up one size larger on your main, and see if it helps..

Dan

 

[marcusgunby]

i would check the float level.

 

[Mxracer510]

Yup. Your lean. Its not bogging because of to much fuel...but because there is not enough to run the engine. Its the same as going wide open with your fuel valve off.

 

[helio]

Thanks all for your time.
I am going check float level and then one size up in main.

Just more one thing...in your opinion can the weight of a rider affecting the jetting ?
More weight more load and so on ?

 

[_j0kA_]

No Prob.!

Its the same as going wide open with your fuel valve off.

Mxracer510, tell me about that :scream: !! A few weeks ago when I was racing AX, I made it to the main and I was so hyped up that I forgot to turn the gas on! I ended up casing a double, and making it through the whoops before my bike stalled and sounded like it fouled! I couldn't figure out what was wrong untill I felt the switch and the fuel was off!! Boy was I pissed off.. I lost an easy lap an a half trying to figure out what was wrong :(


Helio!

No..
The only thing that would happen if you are heavier would be that you are putting more stress on the engine.. You could run an even larger jet just to ease the stress on the engine, but it is not necesary ( spelling? )

 

[helio]

Thanks _j0kA_ for your assistance.

 

[<HONDA>]

Hey did you race at the arenacross at the skydome in toronto _JOKA_?