Before I start can I just let you know that I am based in the UK with a UK spec bike.

Hi folks several months back I took ownership of a non running 1989 CBR1000F, apparently the bike was on the road but had been laid up for a while then tipped over by another bike and left again for a while upright on it's side.

When the owner realised what had happened after it was re sat on it's stand he attempted to start it but refused to start.

Previous owner had tried their best but gave up as he was not prepared to spend cash on what was a winter hack.

I purchased the bike cleaned the carb (ultrasonic) replaced the plug leads as very looking hard and old, placed a new battery on it, replaced the plugs and gave it a good general service.

It would not start?????

Now I have previousy posted a question about the carbs which was sort of been answered, the result of which was a replacement carb purchased and fitted from a running bike.

I have just about checked every obvious simple connection and electronic parts for correct functions.

The valves are correctly working and measured to spec'

The only part that I am unable to check correctly is the spark unit on the side of the frame.

Now the engine turns over fast and smooth on the starter, the plugs ignite with a strong spark but the bke just won't fire up.

I thought it was a fueling issue as the plugs seem quite dry, however I have sprayed a volitile liquid we call Easy Start into the cylinders direct and she tries to splutter but not fire up and everything seems to back fire.

On turnover of the starter there is a lot of back pressure with fuel being thrown back as if the engine has the plug leads in the wrong position - they are not.

So what could be the problem? I am at a loss to understand and really don't want to break it up but I am getting truly peeed off trying to fix this bike

Any ideas folks or things I could try or places on the forum I could back refer to (I have searched the threads) I also have all the manuals I require.

However I need to confirm the following................

Do the two pipes on top of the carb need to go onto the tank?

Does any one have a diagram or photo of where the top pipes go?

Many thanks

 

Hi there Stivh.

Are you absolutely sure you have the leads on the correct plugs? And if the plugs are dry it may be a fuelling issue as well.

Part of the problem is other people have worked on the bike previously, so we don't know what they've done and if it was done properly

That's all I can think of right now.

There is however a lot of experienced guys on here, unfortunately with time zones being what they are it'll be a while before they get on here, so hang in there and check the thread later.

BTW where are you in the UK? There may be someone local that can help.

 

Appreciate your thoughts and more than happy to wait but do need some ideas

Based in the North West UK, in South Manchester area. I don't think the previous owner did too much to the bike and most things seem to be working correct.

Cylinder pressures also seem okay although I haven't put a tester onto them - just the rubber thumb, as I don't have a tester and no one I know has one to loan (£90 to buy??? so no chance there).

I wonder if the spark box is doing it's job correctly, but I need to find a simple way of testing it without buying expensive kit, I might be wrong (hopefully wrong???).

The timimg itself is appears spot on.

 

Hi stivh,

I would have thought that if you're getting a healthy spark at the plugs, then the CDi unit is doing it's job. It does sound like a fuelling problem from what you've described. Have you checked that there is fuel coming out of the fuel pipes that go to the carbs? Are the carb rubbers fitted correctly (air leaks?) at both ends? Are you using fresh fuel? Have you checked that the butterflies and jets are opening properly if you've had the carbs off? Is the choke working properly?

If you have compression and a good spark, then it logically follows that it's fuelling.....

Is yours the mk1 or mk2? It could be either on an 89 plate? Mines a mk1 but 89 regd. I could try to get some piccys of under the tank if yours is a mk1

If ya get it running, I might see you around as I'm only down the road in sunny Blackpool!

Regards,

shakey

 

This is the reason I asked about the plug leads, sounds like a fuelling issue, but if the leads are mixed about as well it might cause these symptoms

 

It does sound like a fuel issue. Does the choke work properly? That will make a big difference in cool weather.

 

Okay I have spent the evening rechecking the valve clearances and springs and all okay and correct, the plugs are sparking fine, they are correctly fitted as per the various manuals I have for the bike. I had the carbs off and drained them and checked that all the exterior functions are okay. They came off a standard running bike so should be okay internally. I have re-fitted them and cannot see any issues with the mounting rubbers - ie air leakage etc. I have not fitted the airbox though as I want to see how the carbs function. Choke sounds as if it working correctly and slides across cleanley.

I will get some fresh fuel......again and try to fire her up tomorrow.

My concern with the CDi unit is whether it can malfunction and create an incorrect spark pattern?

My only other unchecked/unsure issue is the bore pressures although there is a lot of blow back from the carbs suggestion pressure coming from somewhere, I also had some vapour ignition from the carb cleaner at the back of carbs so the spark plugs are giving some ignition. I had a good look into the bores and there is a fair bit of carbon on the piston crowns but no pitting the old carbs where pretty bunged up and I know that the previous owner rode it with a bit of choke on short local journeys.

Shakey this bike of mine originates from the Blackpool area and it has the 20 plus years of salt encrusted rust to prove it. It would be nice to think I could eventually get to the weekly Lytham St Annes gatherings this spring assuming I can get the thing to start otherwise it will be at the Garstang bike jumble in February!!!!!!!! ?

 

Any more progress on this today matey???

 

okay fresh fuel in the tank tonight fully charged battery and not a splutter of life from either of the pots, however when I put the choke on the carbs spit out fuel all over the rear mudguard......stacks of fuel.

I am at a total loss as to what the problem is.

 

Beginning to sound like the timing is waaaaaay off to me.

Did you check it ?