Hi Guys, been a while since I posted last. All is good still got the bike but havent used much. It will be going on Classic Vintage plates early next year. Bike is too good for regular use. Now with 12.000k.

Anyway Im having cold starting issues, kinda had this issue long time but never really addressed it. If bike has been started on day 1 then Day 2 & 3 will start ok. But if left for a week or more its very difficult to get it started.

The way it ought to start: Neutral, choke 3/4 of the way or full. Couple of light turns of throttle. Fire up, starts on hi idle, reduce choke till normal idle holds firm.

Current Behaviour: as above, fire up, takes a good minute or two before I hear engine firing, idle rarely holds as reaches only 3000rev (opening throttle no matter how small engine konks out), keep persisting until engine holds on low rev then slowly builds itself up in revs (instead of immediate hi revs). Slowly decrease choke as revs keep going higher. Then close choke and pray idle holds at 1000. When engine fully warm will idle 1000-1100.

So what I have difficulty in understanding is why wont bike start in hi rev according to opening of choke? Why does it start very low then only rise as it gets warmer.

Bottom line shes a bitch trying to start after standing a few weeks.

battery is great.
fuel 91 (thinking of going 98 Optimax)
could I have re-positioned vacuum hoses wrongly after balancing.
perhaps jets and carby need an overhaul. (am reluctant to pull out and take apart unless I have to.)
Has new petcock filter.
seems initial petrol starvation as no matter how many times with start button theres no reaction from engine....till much later.

So what do you reckon, have you experienced this before yourselves?

PS. Ive done searches but every bike seems to have different issues and model dependant.

 

A couple of pointers
1 FULL choke to start - the choke only comes on at above 80% of movement
2 Don't touch the throttle - it'll flood and be hard to start.
Why does it start very low then only rise as it gets warmer.
Mine does that, always has.
You may want to check your vacuum hose to the first carb - there may be a leak and the bike's not getting all the fuel it should. I'd also look at your air filter and plugs too. Given the bikes age, check your fuel lines for clogging. A weak battery can also be a problem.
Increase your idle to 1200 RPM.
It's hard to tell without looking at the bike, but that's where I'd start.

Bottom line shes a bitch trying to start after standing a few weeks.
A couple of WEEKS ! - Mines's like that if she stands more than 5 or 6 days !
I have found that when she first "coughs" - hold the starter on and hold it on until she's running- IT KEEPS THE HEADLIGHT OFF AND IS EASIER TO START. YOU WON'T DAMAGE ANYTHING. The starter has a clutch.

 

Sounds like my bike.

I'm not to keen on the enrichner system. I would rather have a true choke where you have a better feel for what's going on by actually working a butterfly and controlling the amount of enriched fuel. With the enrichner system, you don't have control. The plunger position is either dumping fuel or not. But your right, touch the throttle before she comes up in RPM and she'll die on you...normal.

I also think its a bit critical to set the idle like Shadow said. I think to low and she'll die, especially if you try to help with the throttle. If its to high, you won't get the enriched fuel you need because the carb butterflies are to open at start, hence the same problem if you try to open the throttle by hand.

 

To me indicative of partially gummed up pilot jets.

A good cleaning of 'em may sort it for you.

 

Am inclined to agree with you Sprock as Im sure the carbs havent been touched in almost 25 yrs. Is there a kit one can buy for overhauling the carbs?

 

yeah there's kits out there man - not cheap tho.

I just went with generic oring sets and cleaned
everything else

 

Don't use Optimax Volvi !!! I've read numerous articles on that stuff gumming up the system even when it sits for a few days ! Go with other brands in the 98 but not Shell if the bike is going to be sitting for any length of time. Shell is ok if you're on a ride and using it quickly but it's not good if your bike sits and doesn't get used for a period of time. Cheers.

 

yup actually meant BP Ultimate I never touch shell for any of my bikes. dunno why i came up with the word optimax. have been using Ultimate for years on my Hayabusa, never misses a tick and cleans the jets. thats why am thinking of using it on the cbr. will be using ultimate to feed my 3rd bike coming in a few weeks.

 

Hi all, been a while since I posted. Thought Id continue on this older thread rather then a new one as I still have the above problem that I wish I could resolve. But before that I should update my status.

I bought a 3rd bike August last year and have been spending most of my time with it. The CBR took a bit of a back shelf for this period. I finally bought a Harley something I thought I would never do in my almost half century of riding. But the '09 Night Train got to me and I love it. If your interested to know more about it I will happily provide you a link in PM but this isnt the forum to harp on about it.

I changed the plugs on the CBR hoping that would benefit my starting issues, cant say it did anything. But I noticed the 1st lead was not connecting to 1st plug properly. So I replaced it with a new one. Bought a Spacer-Ignition (for the lead end) Part# 30520-ML7-000, but did not see the old one anywhere and couldnt see where it would belong. So I didnt use it. Perhaps my '89 model never had them, coz took the part No. off American fish '90 model. If anyone can clarify this issue would be interesting to know.

Im still having starting issues and without overhauling the carby there doesnt seem much I can do. Do you think playing around with any screws like rich/lead would help? or maybe the choke cable has gotten lax and not closing the butterflies properly? Still a mystery to me. Other then that the bike is still perfect...oh, I tried replacing the seat catching latch coz seat hard to remove, but no new latches to be found anywhere in the world today..supposedly, I tried. I taped (insulating tape) up the U section of the unlatching arm to have more contact, helps a bit but only for a while till the tape thins out. Has anyone else found a good solution?

Oh and finally I put the CBR on Classic plates after its 25th birthday a few months back. Its great not having to pay full rego for a bike thats not used regularly and the 45 day is plenty per year.

Cheers to one and all.

 

Volvi PM me a link

Ya know I'd put a good dose of your favourite carb cleaner in the tank and take
her out for a good trashing for an hour and then see where you are at also a nice
clean air filter might be a welcome addition to help her breath better when starting
up.

Just my two C's