Tank Slap - Motorcycle Forum

Been having a few problems with warm starting issues recently there's a few on the CB1R forum having the same problem but know one has come up with a solution so I thought I'd ask if any of you guys have this problem, my bike starts first thing every morning and when I leave work at night again it starts first thing but if I was to start it in the morning and stop off for petrol on the way to work it struggles to start up once after I've switched the engine off and filled up, it happened yesterday afternoon when I left work at 4pm and decided to fill the tank on the way home, haven't had a decent ride out this year but now I'm thinking when I do and I stop 3 or 4 times for fuel am I gonna keep having this problem ?

Needs a service i suspect.

Maybe the plugs are due a change at this one.

Plugs could be an issue.

Have you left the bike to idle when the weather has been warm? These bike can make little adjustments to the air/fuel mix.

Might sound silly, but do you open the throttle at all when starting the bike?

The RSV hates this and only likes warm starting on a fully closed throttle.

Commuting on it might cause this too, Bratty, especially if the bike isn't getting a decent run now and again.

duke63 wrote:Commuting on it might cause this too, Bratty, especially if the bike isn't getting a decent run now and again.

He only goes slow

In all seriousness Duke has a point. Constant short runs on a bike in traffic will put it under a lot of stress. Both my Daytona and my Speed Triple failed and I used both of those for short commutes.

Bratty, is it worth thinking about a cheap hack or a scooter?

Rather than guess I would give a competent bike mechanic a call and ask his advice or book it in for some diagnostics. Won't cost too much and if you don't get it sorted could ruin your whole summer.

Kwacky wrote:In all seriousness Duke has a point. Constant short runs on a bike in traffic will put it under a lot of stress. Both my Daytona and my Speed Triple failed and I used both of those for short commutes.

Bratty, is it worth thinking about a cheap hack or a scooter?

Cars are the same and always better for a long run at speed. There are some cool scoots these days.

Although my ride to work is a long one it does give the bike a decent work out and thankfully there aren't too many spots where I have to sit in traffic.

I don't know what the CB1R guys have said, but my guess would be either the lambda sensor or MAP (manifold air pressure) sensor, if either of those are not to spec they'll cause mixture issues and poor starting/running within the "closed loop" part of the fuel mapping. If all is well with those I'd be checking the intake manifold for air tight connections.
If you had an issue with either the cam position sensor or the crank position sensor it should be flagging a light and a code I'd have thought.

Has anyone from the Honda forum had this issue and gotten it fixed?

if its only happening when its hot its likely to be the starter solenoid overheating

Good point - I read the op as it was turning over but not firing, am I wrong and it's struggling to turn over? If so that's normally fairly straight forward.

Changing the intake manifold rubbers solved this problem on my bike, but I wouldn't have thought your bike is old enough for the rubber to have perished.

check your earths and also the contacts to the starter solenoid they can get pretty crusty and cause the solenoid to overheat

Cheers guys, hopefully I'll give it a good blast on Sunday and see what it's like then, I've used it for the last six months but only for my commute I don't think it's been over 5k revs but it might do on Sunday.

I had a ZZR 600 which had the same problem, got to the point where I couldnt stop at a garage to fill up when the bike was hot, had to keep topping it up with a jerry can at home, it was something to do with the valves not allowing the engine to catch whilst warm, I was quoted over £300 to fit new shims and sort it out but sold the bike to a dealer in the end, shame really it was a nice bike, dunno if thats any help, I'm a bit techically challenged