I just picked up an F1 from a friend who had it running a few weeks ago. It didn't even want to crank when I got it. I am using a power probe to get it to crank, because the run/off switch has no power wire going to it at the moment. Where are the fuses on this thing? Only one I found is for the starter relay. I also had to manually power up the fuel pump but i can't get the engine to sputter, even with some starting fluid. Where can i find a wiring diagram and diagnosis tips? For testing the CDI and whatnot. Thanks.

 

If you just want the wiring diagram, it is here:
https://cbrforum.com/forum/attachmen...-87-wiring.jpg

If the starter motor turns, it's not the kickstand switch or the neutral switch so I would move onto other items.

I would start with looking up the ignition system in the manual - start at page 87:
https://archive.org/details/HondaCBR...0ServiceManual

It is fairly detailed so should cover all the main issues for you.

Good luck
Iain

 

Thank you!

I can only turn over the starter/engine if I give power to the black/white wire with my power probe. I chased this wire down to the coil packs, but couldn't find where it came from there. I see on the diagram it comes from the "spark unit" at least I think that's what it says. The font gets blurry when I zoom in. I may have to check/bypass my kickstand switch and neutral switch to see if they are cutting off power.

 

The wiring diagram is in decent resolution in the manual on page 407:
https://archive.org/details/HondaCBR.../n407/mode/2up

It isn't in colour however, but does have the colour lettering on each, so won't be too hard to work out what is what.

It sounds like you have a lot of troubleshooting to do, so it may be worth bypassing the side stand and netutral switches, use a multimeter to test the handlebar kill switch and ignition switch outputs and test everything from the assumption that it could be faulty so needs cleaning and testing. It will take time but will build confidence that each thing you look at is one more thing that is in good shape.

Ideally I would like to have a similar bike available to swap each unit out to test (handlebar switch, coils, engine management unit etc) but without this you will need to be methodical and patient.

A good start would be to print out the wiring diagram for your model and work through each separate unit until you are confident it is ok then cross it off the list of ignition components and move onto the next. My priority list would be the fuses, ignition switch, handlebar kill switch, sidestand and neutral switch, coils and engine management unit (in decrecing order of importance).

With the EMU I would try to test it in another bike before replacing it as these are not a common failure and an expensive one to replace.

thanks
Iain

 

I will print that manual and give it another go tonight. I'll be back to report my progress. Thanks again for the help!

 

Found a bad fuse. Now engine turns over with the Start button. The fuse box was wrapped in a rubber hose and electrical tape and shoved between the valve cover and radiator. Engine backfires pretty bad, seems like it's out of timing. I need to make sure all the plug wires are going to the correct coil pack. I had this issue on a 97 Accord once. I also tested the Spark Unit and it seems to be ok. Making progress, slowly but surely.

 

A common cause for this is air leaks in the rubber manifolds of the carbs - an easy test is to spray some starter fluid (or brake cleaner if you have that to hand) onto the intake stubs and if the engine starts to rev briefly then you have air leaks, probably caused by perished, cracked rubber.

It would be helpful to know where in the rev range it backfires - if it is when the revs are rising then I think the inlet side is most common, if it is when the revs are dropping then it is often an exhaust leak (should be easy to feel the hot air coming out of a joint, hole or where the exhaust header pipes meet the head. If it is all over the place then it is pointing to electrical issues.

The timing should be electronic on this bike I beleive so short of the cam chain being a tooth off, it should be ok. You could have a faulty engine management unit of course but these are uncommon and are normally going to stop the bike running at all.

But your perseverance is paying off - keep at it

 

The backfire happens when trying to start the engine. The engine is not even running when it backfires. It sounds like it's trying to start and then BOOM a backfire blows out the exhaust.

 

A decennt generic troubleshooting guide to backfires can be found here:
https://axleaddict.com/auto-repair/E...res-Diagnostic

It sounds like unburnt fuel is getting into the exhaust and igniting, causing the bang. The first thing I would do there is clean the spark plugs and check if any are fouled - if any are oiled up then you have cause for concern but hopefully some are just fouled with crap from the carb if it has been sitting for a long time. If you can, drain the tank and carb bowls and put in some fresh fuel - it will give you a chance to check for rust and debris in the tank too.

If you haven't already got one, an in-line fuel filter is a very cheap way to stopping flaked of dust and other debris from an old fuel tank from reaching your carbs.

Thanks
Iain

 

A full color wire diagram, as well as the entire factory service manual is located in the sticky at the top of this forum. The LAST post in the sticky, from me, has the link to my MEGA.nz account where it is hosted, free for all.

On the not starting, then backfiring issue. The carbs on these bikes are super picky. They gunk up, and sometimes stick the floats open, flooding the fuel into the engine in a stream. As it is a fuel pump fed bike it doesn't flood in until you go to start it, having the pump start pushing it into carb, then the cylinder. First order of business on any Hurricane is clean those carbs with compressed air, brushes, acetone, carb cleaner, everything. Be hyper vigilante about the seals as acetone will destroy them and there are a ton of little O rings inside. Use WD40 to clean and recondition the seals. Any metal part give it the acetone treatment, Then carb cleaner through every single port on it with those micro brushes.

The rubber boots get old and start cracking and let the air/fuel mixture get out of whack, soak the boots in WD40 for a couple of days to see if they are salvageable.

The Hurricane had a factory fuel filter inline stock, you can easily swap a new one in.

On the timing, if someone pulled all the plug wires off and did not put them back on correctly, that's the only way your timing would be off. It's a CDI box with a trigger that runs off the engine crank speed. Again the manual I linked has the firing order and full mechanical teardown and rebuild of the entirety of the motorcycle.