Bogging issue

[ccmnova]

Had the 74 125 Penton out today - was running good but started the bogging. I searched and found some posts abt bogging but could see no real solution.  Even sometimes when stopped, try to rev and get bogging - then all of a sudden it will rev.  Put on choke and engine dies - could it be running way too rich ?  Should i try putting the needle jet one notch lower ? \ Any ideas here on what to check ?

[Steve Minor]

Could be the pilot circuit. Check out the video link below. I know they are different carbs but the theory is the same.


https://www.youtube.com/watch?v=zVzqqpgviyI

[Daniel P. McEntee]

Also research adjusting the air screw. That needs to be done when the engine is wormed up. usually 1 to 1 1/4 turns is in the ball park, but some times subtle adjustments make a difference. Make sure your air filter isn't over oiled either. On Bing carbs, a small notch about 1.. deep and 2mm wide in the bottom of the slide helps with coming off idle more cleanly. Dropping the needle a notch is a bigger adjustment, and keep watching your spark plug. Make any adjustments you make one at a time and give it time to make a difference.
  Type at you later,
  Dan McEntee

[ccmnova]

Could any of these be the issue ??

B8HS NGK .25 inch gap
(i did get an equiv iridium plug but not sure if i should use it)
- 135 Main jet
- 2.76 Needle Jet
- 6G1 Jet Needle in position 2 from the top
- 35 Idle
- air screw ~ 1 turn out

[Mickey Sergeant]

What doe's the plug look like?.Need to take a plug reading to get an idea where your at.  Can you get it to clean out once you get it on the top end. Or doe's it blubber on top end. Is it bogging like there not enough fuel or blubbering like to rich.

[Daniel P. McEntee]

Mickey is correct. You need to know the difference between a hesitation because it is lean, or bogging and blubbering because it is too rich.
  Type at you later,
   Dan McEntee

[Mickey Sergeant]

What fuel and premix ratio are you using?

[ccmnova]

quote:Originally posted by Mickey Sergeant

What fuel and premix ratio are you using?

using 33:1 and high octane fuel

[ccmnova]

quote:Originally posted by Mickey Sergeant

What doe's the plug look like?.Need to take a plug reading to get an idea where your at.  Can you get it to clean out once you get it on the top end. Or doe's it blubber on top end. Is it bogging like there not enough fuel or blubbering like to rich.

Its hard to say if too lean or too rich but when I put on the choke it dies immediately - that's why I thought it was too rich.

I was going to lower the jet needle one notch and see what happens.

[G Ellis]

It should die when you put the choke on, after it warms up. When choke is on it puts more fuel in. My guess lean pilot jet.

[Mickey Sergeant]

I'm with Gary. 35 pilot is smallest I have seen, 40 or 45 is probably where you will end up. I have a 28mm mikuni on my 100 and I run a 50. My motor isn't stock though. I would be careful with that 135 main also. Once you get pilot correct I would do a top end run to make sure your not to lean on top. Would hate to see you sieze it.

Mickey

[Steve Minor]

One time I was having some trouble dialing in a 72 Six Day. An old POG buddy sent me this set up suggestion.....

Bing , 27 mm type 53 stock on a Penton 125 B engine
140 or 145 main jet ( all this depends on how hard you ride , the type air filter and what fuel oil mix you use )
276 needle jet
40 , 45 pilot jet
B slide
#4 jet needle

[gooddirt]

He has a new modern bing... who knowns if the starting base line is in the ball park at all?

[gooddirt]

I'd ohm check the motoplat could be some what at fault .

[Dale Sonnenschein]

If the bike ran good and just started bogging, jetting usually isn't the problem. make sure the air filter is clean and no obstructions in the intake. Also make sure the pipe is clear too. Ignition could cause it too but hard to diagnose.

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