Also Check Out
ATVFlorida.com
PinballShark.com

© 2014
HondaCB1.org Message Forums
April 07, 2020, 03:58:43 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News: Welcome to HondaCB1.org! Please register in the Forum to post messages or view attached photos.
 
   Home   Help Search Login Register  
Pages: [1] 2 3 ... 6
  Print  
Author Topic: Frustrating starting problem still happening  (Read 25509 times)
JamesM
Jr. Member
**
Offline Offline

Location: UK

Posts: 95



View Profile WWW
« on: March 22, 2016, 03:45:00 PM »

Hey guys,

Sorry to post with another tech question so soon but I am still experiencing occasional frustrating starting problems and I'm getting to my wits end. This is going to be a bit of a long post I'm afraid but I'm hoping you CB-1 wizards may know what I'm missing.

I've had my CB-1 since 2001 and occasionally it is a sod to start. Over the years I've tried to solve the problem and the starting has greatly improved to the point the bike is about 90% reliable!
Second day back riding to work after sorting the lovely new exhaust and I've just spent 30 mins in the work car park trying to bump start. Yesterday and this morning I had not the slightest issue and the bike has been running great. Eventually this evening I had to get another biker at work to give me a push. The battery was charged and it had plenty of fuel.

The problem:

When this thing happens the bike will just crank and crank like there is no spark (the battery was fully charged at the weekend and it was turning over strongly). I've tried all manner of starting procedures, choke / no choke, fuel tap on / off, leaving the bike sitting with the tap on/off. When it decides to do it, the only way to get it to start is to bump it. It's so reluctant it usually requires someone sitting on the bike and another pushing. Once you drop the clutch in 2nd a couple of times it'll cough into life and run fine. You can then turn the ignition off, back on and it'll catch straight away on the starter like nothing ever happened. It's weird and I have tried everything I can think of to remedy it over the years. It's very annoying because the bike runs great otherwise and is a joy to ride! I got the bike home, tried starting again after 20 mins and no problems.

Over the winter I stripped and cleaned the carbs / jets, replacing the seals, I thought this was the cause. I've also been through the whole charging system and replaced practically everything.

Here is a list of whats been done over the past few years in case it helps narrow it down:

- Yuasa battery about 18 months old (holding charge fine when tested)
- New coils about 2 years ago
- New HT leads 2 years ago
- New plug caps and resistors 2 years ago
- New starter solenoid 2 years ago
- New standard plugs 18 months ago
- New rectifier 2 years ago
- New electrex stator last summer
- Both main earthing points cleaned
- Starter motor cleaned and brushes replaced 2 years ago
- Carbs and jets stripped and cleaned 3 months ago
- New air filter last year
- Oil and filter 2 weeks ago

I've just tested it again and the bike is charging fine and turns over strongly on the starter. Mechanically its running absolutely fine and usually starts on the button whatever the weather, sometimes needing full choke when cold.

A friend of mine used to have a CB-1 years ago and eventually sold it after having similar issues with starting. I've witnessed his doing the same thing, does this happen to you guys? I appreciate these bikes are 25 years old, but mine has always done this when I got it when it was 10 years old. I feel like I've been through all the obvious causes, I thought it was electrical, then mechanical, now I don't know.

I've owned other bikes alongside the CB-1 I've used for commuting in the past, but at the moment with mortgages etc, I can't afford another and to keep the CB-1. When you push that starter, you don't know if you're gonna get the 10% bad luck. I would put it in with a mechanic but it could cost a fortune to track it down.

One last thing I've noticed, it most commonly happens on the return ride although the bike has been off for about 8 hours.

Any ideas would be very much appreciated, there has to be a reason it keeps doing this. I'm starting to lose the faith Sad

Cheers in advance,
James
Logged
ptlcb1
Hero Member
*****
Offline Offline

Location: Michigan, USA

Posts: 1136



View Profile
« Reply #1 on: March 22, 2016, 05:40:42 PM »

A_morti... your assistance is needed on this post.  Smiley
Logged
VintageHunter
Hero Member
*****
Offline Offline

Location: SHAMBHALA, CA

Posts: 1410


View Profile
« Reply #2 on: March 22, 2016, 07:39:07 PM »

wondering if you have some sort of "vapor lock" going on?
perhaps some fuel isn't allowed to travel properly.

My uncle had a GB500. same thing it sounded like.
When the bike was run and it sat, and it was 'hot' lets say, seemed the tank built up with negative pressure or something and he'd have to let the bike sit for 10-15 m, open up the tank cap and let her breath a bit....then she'd fire right up.
very strange. he never sorted it out and got tired of that vapor lock and sold the GB500 to fellow in CA.
Logged

a_morti
Hero Member
*****
Offline Offline

Location: Gibraltar

Posts: 2091



View Profile
« Reply #3 on: March 22, 2016, 08:12:51 PM »

I would say most of the main culprits have already been covered.

Since you're in the uk and it's winter I would assume it's a cold start issue. Maybe your choke cable is stretched and not pulling the choke fully open?

Maybe you have a small air leak which is weakening the idle mixture? Maybe you need to go up a main jet size due to your exhaust? Maybe your fuel filter is degraded and reducing flow? Maybe the 1.5 year old battery is past best? I used to get about 2-3 winters off a battery no matter cheap or expensive.

Just some ideas from an old hand, no guarantees.
Logged

Cam Drive Gear Train Smiley
a_morti
Hero Member
*****
Offline Offline

Location: Gibraltar

Posts: 2091



View Profile
« Reply #4 on: March 22, 2016, 08:14:04 PM »

Is it worse when you're on reserve tank? That would indicate water in the fuel (water settles) and most likely a linked or blocked drain hose.
Logged

Cam Drive Gear Train Smiley
a_morti
Hero Member
*****
Offline Offline

Location: Gibraltar

Posts: 2091



View Profile
« Reply #5 on: March 22, 2016, 08:17:26 PM »

If bump starting works it's your battery. Really common for a battery to show good volts resting but doesn't have the muscle under load.

Sorry for multiple posts. Rum.
Logged

Cam Drive Gear Train Smiley
ptlcb1
Hero Member
*****
Offline Offline

Location: Michigan, USA

Posts: 1136



View Profile
« Reply #6 on: March 22, 2016, 09:44:56 PM »

LOL!   Rum.  a_morti...carry on.   Grin
Logged
VintageHunter
Hero Member
*****
Offline Offline

Location: SHAMBHALA, CA

Posts: 1410


View Profile
« Reply #7 on: March 22, 2016, 09:53:11 PM »

I think Morti is on to somepin......I had just acquired a 2002 VFR 800 Interceptor (by the way it's for sale) from the only owner my cousin.
He said he had the battery on trickle charger for 3 years.....so i got the bike. Checked voltage all was good but the battery would only be able to crank once or twice at most......then it immediatly died. And a VFR is a pig to push jumps start. Anyhow...I think Morti is right.
If bump starting works it's your battery. Really common for a battery to show good volts resting but doesn't have the muscle under load.

Sorry for multiple posts. Rum.
Logged

JamesM
Jr. Member
**
Offline Offline

Location: UK

Posts: 95



View Profile WWW
« Reply #8 on: March 23, 2016, 09:59:32 AM »

Thanks for the reply's, its given me some useful things to help find the problem!

A couple of them I think can be ruled out, its had a new fuel filter recently and I checked the fuel line and tank breather were clear so I don't think its fuel supply. The pump seems to be working fine as well.

I did wonder if the jets could be an issue with the new can, its starting and running absolutely fine most of the time (rode it in again today and had no issues) though so if the sizing was wrong wouldn't it be a constant problem?

This problem happens on main tank and reserve so I haven't noticed a pattern there.

I was suprised about what you said with the battery potentially being knackered after 18 months but it does make sense. I wonder if some evenings when I go to start the bike, if it doesn't catch immediately it floods and with a weaker voltage it doesn't have enough kick to get it going. Once bumped it pushes everything through, making it easier for a weaker spark to catch?

I checked and cleaned the choke cable when I cleaned the carbs and it seems to be moving the plungers full travel. I also checked the carb inlet manifolds for leaks and they appeared to be well sealed.

Interestingly colder starts when its been in the garage overnight seem to be the easiest and the bike fires into life on the choke no problem. Its when its sat in the basement carpark at work for 8 hours where the air is warmer that it has the issues. Indeed I noticed this last summer, warmer air seems to be a factor.

Its so intermittent it makes it hard to track down, it might not happen again for a weeks now. I'm going to carry tools and my multimeter with me to measure the battery voltage when it happens again. What is the reading again that it needs when turning the starter? No less that 12.5v I seem to recall?

Logged
Sixdog
Jr. Member
**
Offline Offline

Location: Los Angeles, CA

Posts: 55



View Profile
« Reply #9 on: March 23, 2016, 12:10:23 PM »

James. Morti is on the money with his post. The voltage reading will not give you the amp reading that you really need to look for. A battery at 13.5 volts could still have low amps (muscle) so you would need am amp meter...expensive.

Have you set the air mixture screws properly and what is the condition of the needles. Make sure the oring and washer are there and no obstruction ( crumpled up oring...don't ask ) are present.

My 2 cents...

Logged

1979 CBX RED, 1979 CBX SILVER, 1982 Suzuki GS1000sz, 1984 Honda VF1000F Interceptor, 1990 Honda CB1, 1993 CBR900RR, 1995 CB1000 Big One, 2007 CBR1000RR Repsol, 2007 HD Fatboy, 1976 Kawasaki KZ900
JamesM
Jr. Member
**
Offline Offline

Location: UK

Posts: 95



View Profile WWW
« Reply #10 on: March 23, 2016, 04:05:29 PM »

Cheers guys, I understand what you're getting at with the amps. I'll pick up a new battery this weekend and hopefully that'll cure it. The bike did the same thing again this evening and needed a bump, so its something I want get sorted. I'll let you know how I get on.

With the air mixture screws I set them 2.5 turns as recommended on the forum, replaced the o-rings and checked the washers. The needles, slides and diaphragm looked fine but I'm no expert, was my first experience of doing the carbs!

Thanks again,
James
Logged
Pod70
Hero Member
*****
Offline Offline

Location: Gravesend, England

Posts: 520


View Profile
« Reply #11 on: March 23, 2016, 04:59:43 PM »

Something else to check is the kill switch. My last CB-1 would often crank over but not fire up if left out overnight. The problem turned out to be corrosion on the kill switch contacts and the damp just made things worse. The kill switch only cuts power to the coils so it will still crank over but not fire.
Bit of a long shot but worth checking out
Logged
a_morti
Hero Member
*****
Offline Offline

Location: Gibraltar

Posts: 2091



View Profile
« Reply #12 on: March 23, 2016, 07:37:15 PM »

Something else to check is the kill switch. My last CB-1 would often crank over but not fire up if left out overnight. The problem turned out to be corrosion on the kill switch contacts and the damp just made things worse. The kill switch only cuts power to the coils so it will still crank over but not fire.
Bit of a long shot but worth checking out
Good shout. I've found a dead spider in there once which cut the contact. Not easy to work out.
Logged

Cam Drive Gear Train Smiley
bobbyp66
Jr. Member
**
Offline Offline

Location: Philadelphia, PA

Posts: 6


View Profile
« Reply #13 on: March 23, 2016, 10:52:55 PM »

Hi all,

I have an 89 CB1 with a similar problem.

Essentially, it won't start off the button when cold, although it seems to be cranking very strong.  Starts immediately and runs well when bumped, and will start immediately with the button if warm (albeit with a little bit of throttle).

I cleaned the carb and restored the choke function over the winter (which did improve the ability to bump when cold).

I've wondered about the battery as I don't know the age, but it seems to crank very strong (turns over so quickly, I wonder at times about compression).

I'll be interested to see how the OP makes out with a battery change and would love to hear other suggestions for my situation.

Cheers!
Logged
Sixdog
Jr. Member
**
Offline Offline

Location: Los Angeles, CA

Posts: 55



View Profile
« Reply #14 on: March 23, 2016, 11:30:11 PM »

Guys correct me if i'm wrong but start up and idle circuit is the air mixture screw. If you have spark then you gotta look at the idle circuit.

I did have a bad coil once....not reliable when cold start but always fired when warm. Make sure spark plug caps are tight on the wire and check the wire itself. I think someone else mentioned this before.

 
Logged

1979 CBX RED, 1979 CBX SILVER, 1982 Suzuki GS1000sz, 1984 Honda VF1000F Interceptor, 1990 Honda CB1, 1993 CBR900RR, 1995 CB1000 Big One, 2007 CBR1000RR Repsol, 2007 HD Fatboy, 1976 Kawasaki KZ900
Pages: [1] 2 3 ... 6
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!