Author Topic: idle to 4k rpm bogging in 1st  (Read 2632 times)

Offline Amdalthon

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idle to 4k rpm bogging in 1st
« on: August 18, 2012, 02:36:29 AM »
Hi, I previously thought I had my problem fixed but when I went away on holidays the bike sat for about a week. I got back and tried starting my bike and it idled poorly so just like usual I peel the carbs off. So far this week I've had the carbs off my bike every day and multiple times a day trying different things. If any one has any suggestions please let me know, it would be much appreciated. The bike has 47000km(29000 miles) on it and the pilot screws are pretty worn out from people over tightening them so they have grove in them. I am not sure if my diaphragm holes have been drilled out since some kits tell you to drill them out. if any one has measured or knows the size of the holes it would be very useful.
Current settings:
Unknown needles with the clip in the middle
Cut diaphram springs
Mikuni 100 main jets(stock)
32.5 pilot jets(stock)
1/2 turn pilot screws
16mm float height
K&N air filter
Hindle exhaust
New viton o-rings
New bowl gaskets and float valve needle

These are some things I have tried so far.
I cleaned every single passage and jet and threw it all back onto the bike. I am still having the same problem I had before when it bogs in first gear between idle and 4000 rpm. I cant pull away from a stop light smoothly unless I ride the clutch to 4000 rpm. Not vary safe for city riding. The floats are set to 16 mm since the tail pipe is like BLACK ASH and it is very rich. I have also tried changing the float levels between the minimum and maximum and no real difference. Also I noticed my battery boiling over. I haven't checked if my bike is overcharging yet.

 I purchased stock needles, diaphragm springs, and air filter. I tried the stock air filter, springs, needles and 100 mikuni main jets and it still didn't pull from idle.. also it has the dead spot at 6k rpm. Putting everything back to stock except the exhaust should have got it back to normal but it didn't. I replaced all the o-rings with viton o-rings, just to be safe. I have tried every thing from 0-4 full turns of the pilot screws and it does not effect it. its the happiest and idles decently at 1/2 a turn.

I have a feeling like I might need to downsize my Main jet since it is still so rich.  I tried the bike without an air filter and it seemed to improve its pull in the low end but once it warms up it goes back to normal and starts to bog between idle and 4000 rpm. If I am in 1st gear and rolling  at 2300-2500 rpm it will accelerate like it is supposed to, but not from a complete stop. It will bog until 4000 rpm. but like I mentioned once I am rolling and get past 4000 rpm and go back down to 2300-2500 rpm without stopping it will accelerate.
« Last Edit: August 18, 2012, 02:51:36 AM by Amdalthon »

Offline interfuse

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Re: idle to 4k rpm bogging in 1st
« Reply #1 on: August 18, 2012, 09:34:41 AM »
Sort out your regulator / battery first. A bad regulator / battery can cause poor low end performance. The first time my regulator failed causing the battery to die the bike wouldn't run below 3k rpm. It ran fine after the charging system took over from the battery.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline Amdalthon

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Re: idle to 4k rpm bogging in 1st
« Reply #2 on: August 20, 2012, 06:30:10 PM »
Yesterday I went out and bought 92.5 Main Jet and it really improved. I might need to raise my float height but even when im at 8k rpm in 6th, I still pull away like a rocket. it seems like my bike is STILL running very rich. i was thinking of even going down to a 90 Main jet but for now 92.5 is just great. When i had my pilot screws out more it was even worse. it gets way way to rich with them more open.