maxi bogging at high speed. help????? :(

General discussion forum for repairing and riding mopeds

Moderators: ItsLookingUp, pehuskey, Tab, mountainmoped, JD, John

maxi bogging at high speed. help????? :(

Postby seth » Sat Sep 24, 2005 9:23 pm

So yah, the thing runs like a champ except for this.. When I get up to speed it sometimes starts bogging on me and if I dont let up it will just die... Anyone have any ide how to fix it?
seth
Net Rider
 
Posts: 190
Joined: Thu Sep 22, 2005 11:27 pm
Location: New Jersey

re: maxi bogging at high speed. help????? :(

Postby Smitty » Sat Sep 24, 2005 9:50 pm

try cleaning the carb and fuel system...sounds like it may be starving for gas at top-end...
Image
User avatar
Smitty
Master Regional Rider
 
Posts: 3854
Joined: Sun Jun 06, 2004 3:18 pm
Location: Northern S.C.

re: maxi bogging at high speed. help????? :(

Postby don-ohio » Sat Sep 24, 2005 10:00 pm

yes.......it sounds like a `gas shortage'...LOL! Usually if it's a clogged gas cap vent,it won't die if you hold it open,but it'll cut out and slow down,then pick up again. So it's probably what Smitty said...fuel restriction at the petcock(in-tank filter screen), filter at barb inlet, or dirt in the needle seat inlet. don-ohio
`Ped `til yer RED!' ......`NO small-wheeled pothole divers need apply! LOL!' don-ohio (:^D
don-ohio
Regional Rider
 
Posts: 2831
Joined: Fri Nov 28, 2003 9:24 am
Location: Jackson,OH

re: maxi bogging at high speed. help????? :(

Postby seth » Sat Sep 24, 2005 11:45 pm

Interesting but Im not sure if thats right. I can drive it at high speed for quite some time, maybe 60 seconds.. then it will start bogging. Sound wierd?
seth
Net Rider
 
Posts: 190
Joined: Thu Sep 22, 2005 11:27 pm
Location: New Jersey

re: maxi bogging at high speed. help????? :(

Postby don-ohio » Sun Sep 25, 2005 12:16 am

When you say it bogs, you mean it will `catch' again at a lower rpm? Then it might be any of the things Smitty and I mentioned, INCLUDING a clogged vent in the gas cap.
To check that, just loosen the gas cap and take-off and see if it still bogs. don-ohio
`Ped `til yer RED!' ......`NO small-wheeled pothole divers need apply! LOL!' don-ohio (:^D
don-ohio
Regional Rider
 
Posts: 2831
Joined: Fri Nov 28, 2003 9:24 am
Location: Jackson,OH

Re: re: maxi bogging at high speed. help????? :(

Postby Smitty » Sun Sep 25, 2005 5:22 am

seth wrote:Interesting but Im not sure if thats right. I can drive it at high speed for quite some time, maybe 60 seconds.. then it will start bogging. Sound wierd?


...no, not wierd at all. The symptoms you are describing sounds like could be caused as Don-Ohio pointed out by a vacuum in the fuel tank (clogged cap vent, unable to "breath"), all the way through to fuel valve being restricted with debris, fuel inlet filter in carb clogged, needle valve and seat in carb dirty, main jet and / or other circuits in the carb itself restricted. Have you cleaned the entire fuel system??? Have you disassembled the fuel valve, and not got the inside parts of the valve realigned properly? Is your fuel line crimped at any point?
Are you running without an airfilter? This could also fit you description of symptoms.
Image
User avatar
Smitty
Master Regional Rider
 
Posts: 3854
Joined: Sun Jun 06, 2004 3:18 pm
Location: Northern S.C.

re: maxi bogging at high speed. help????? :(

Postby wardie » Sun Sep 25, 2005 7:26 pm

I agree with Smitty and Don-O you are definitely having a fuel starvation problem because it dies. If you needed a bigger main jet it would bog at full throotle at speed and if you left off on the gas slightly would pick up and stop bogging. That is a sign of a jetting problem. You said it dies so I think its in the fuel system. Do one thing a a time and test it, that way you'll know what fixed it. Follow the instructions by Smitty and Don-O and I'm certain you'll find your problem. One other thing check your float heights and mesh screen in the carb inlet and add a fuel filter. Wardie
wardie
Regional Rider
 
Posts: 715
Joined: Tue Dec 28, 2004 11:46 pm
Location: Youngstown,Ohio

re: maxi bogging at high speed. help????? :(

Postby seth » Mon Sep 26, 2005 3:21 pm

Okay I cleaned the carb, new fuel line w/ filter, cleaned petcock, put it all back together. STILL is bogging after a while. I relized ut happpens even at mid speed if you hold it there constanly. I removed the gas cap as suggested and that didnt make any difference.

So it still bogged out..

Now I took off the spark plug which is a few days old. It was soaking wet and black as could be. Obviously Im super rich... even with no air filter... but how do i lean it out?
seth
Net Rider
 
Posts: 190
Joined: Thu Sep 22, 2005 11:27 pm
Location: New Jersey

re: maxi bogging at high speed. help????? :(

Postby TowerTower » Mon Sep 26, 2005 5:46 pm

Sounds like it may be time for a carb rebuild. But before you do that you can try to adjust (tighten) the fuel mixture at idle:
First, check visually for any air tube blockage.
Otherwise, while engine is hot,
- screw the idle screw in several turns so the engine is idling fast, say 1500 - 2000 rpm
- tighten the fuel mixture screw until the engine stops running smoothly (begins to starve for gas), then turn back until its just smooth again.
- you can also play with the air-mixture at idle screw, turning it out to add air and effectively leaning out the mixture at idle (its easier to deal with one at a time though)
- adjust the idle screw until you're back at a normal idle speed.

This should make the carb as lean as possible without rejetting and should eliminate any fuel mixture complication that might be introduced by the idle speed circuit. If this fixes the problem at full throttle, you're done.

(On the down side, if you set the mixture at idle too lean, the engine may tend to overrun on shutdown, if this happens, unscrew the mixture screw 1/8 turn and try again).

If this doesn't work, look to the full-throttle circuit for the problem (fuel bowl, float, main jet, atomizer, and tapered needle). The most likely problem, is debris blockage or varnish built up on the jets and needles and one or more that may have to be cleaned and reseated. Second most likely is physical damage (bent needle). You may need a carb kit to fix these types of problems
User avatar
TowerTower
Net Rider
 
Posts: 750
Joined: Fri Sep 23, 2005 11:18 am
Location: Toronto, Canada

re: maxi bogging at high speed. help????? :(

Postby Smitty » Mon Sep 26, 2005 6:32 pm

The Bing carb on a Puch Maxi doesn't have an air mixture adjustment screw.

Has the metering needle in the throttle slide been removed / adjusted?
Image
User avatar
Smitty
Master Regional Rider
 
Posts: 3854
Joined: Sun Jun 06, 2004 3:18 pm
Location: Northern S.C.

re: maxi bogging at high speed. help????? :(

Postby TowerTower » Mon Sep 26, 2005 8:09 pm

Thanks @Smitty, Although I have some familiarity with larger 2-stroke carbs, I'm not at all familiar with Puch carbs, sorry. In editing the message, I added the air mixture bullet just to cover all bases.

Also, I'm assuming the basics have been covered. The choke isn't stuck, or the air filter isn't clogged, for example :)
User avatar
TowerTower
Net Rider
 
Posts: 750
Joined: Fri Sep 23, 2005 11:18 am
Location: Toronto, Canada


Return to Moped Riders

Who is online

Users browsing this forum: Bing [Bot] and 0 guests

cron