Starter Clutch

[Joff]

Any ideas on how to test the starter clutch and any tips on removing it? I'm having ongoing starting problems. Ive replace (over a couple of years) the following: plugs, coils, battery, air and fuel filters. HT leads seem OK but I will be replacing them soon anyway. Starter turns over well.

[a_morti]

Any ideas on how to test the starter clutch and any tips on removing it? I'm having ongoing starting problems. Ive replace (over a couple of years) the following: plugs, coils, battery, air and fuel filters. HT leads seem OK but I will be replacing them soon anyway. Starter turns over well.

If the starter turns (you can hear it) but it isn't apparently connected to the motor, then your starter clutch is most likely broken. Take off the front left cover, you can see the starter clutch. Take it out, there is a bearing which should be a one-way or "lock-up" bearing. If it isn't doing that, it's broken. Removal is easy, but do take attention to put the ignition advance back on at the right angle. It's part 6 here:



Unfortunately they're stupidly expensive from Honda so with any luck you can turn one up from another source!

[Joff]

Cool. Ive got as far as taking off the side cover and exposing the starter clutch and rotor etc. In the manual its suggest that I remove the other side cover and use the "special tool" and an assistant to hold the crank whilst undoing the bolt for the rotor and starter clutch. I was going to try the putting the bike in gear with a block of wood through the back wheel trick to avoid the whole "special tool" thing. I'm not totally convinced this is a good idea but think its my easiest option?

[clarkdw]

Blocking the drive will probably work but if you do that don't just put the wrench or socket on with a big pipe and put all your weight on it. Try to use an impact gun, air or electric if you have access to one or use a six point wrench or socket and a hammer. This will greatly reduce the chance of breaking something.

I am not really clear on whether your engine is turning when you try to start the bike or is it just the starter making noise?

[a_morti]

Cool. Ive got as far as taking off the side cover and exposing the starter clutch and rotor etc. In the manual its suggest that I remove the other side cover and use the "special tool" and an assistant to hold the crank whilst undoing the bolt for the rotor and starter clutch. I was going to try the putting the bike in gear with a block of wood through the back wheel trick to avoid the whole "special tool" thing. I'm not totally convinced this is a good idea but think its my easiest option?

I got one off before by using a rattle-gun. You might struggle without one.

[Joff]

The starter runs ok and turns the engine over but it seems like only some of the power is being transfered to the crank. You can feel air being pushed out of the exhaust as the engine turns over, but the puffs of air seem weak compaired to a mates CB-1. After a few tries of the starter I usually end up bumping the bike. In 2nd gear it always fires up with only a 5-10 meter run suggesting the rest of the ignition system is ok? As much as I love the exercise, its getting a little embarrassing.

[clarkdw]

If the engine is turning, the chance of the starter clutch being the culprit is very small. To make the engine not start because of that would mean that it is turning very noticeably slower. I think I would replace the wires first. If it starts by bumping it sounds like an ignition problem with weak spark when the battery is losing voltage turning the engine with the starter. It should be turning much faster with the starter than when you bump it in second gear.

If you are replacing the wires anyway it makes more sense to try that first to save the expense and work of doing the starter clutch.

[91cb-1]

If you need it i have a starter clutch that i pulled off a great working engine. i had to use an impact driver and a socket on the cutch nut but it's a 50/50 chance on which nut's gonna come off that way. i do however agree with cark change plugs. check your ht wires multimeter the whole battery alternator reg/rec system befor putting on a new starter. these engines are mechanicay bulet proof. if there is anything wrong with your -1 it is more likey to be electrical than mechanical. i was taking to a friend who works in a bike breakers here in Ireand and he said that anytime they get a -1 in the first thing they do is chuck the engine into a skip because nobody needs them!

[Joff]

Ok. Thanks to everyone for the advice 

Ive got some new HT wires already so ill change them just in case. I can check spark plug condition when I change them. Ill also recheck ignition coil resistances and alternator/rectifier/battery to see if there are any other issues. Probably won't get a change till the weekend but ill post up my findings when ive done the above

[Joff]

Ive now removed checked and re-fitted the starter clutch. This is all back and seems ok. I wouldn't have bothered with this if I hadn't already removed the casing last weekend (before the advice from everyone on the site about the leads etc. this week).

I checked the coils and leads. The coils gave good readings and the spark plugs were fine. I had trouble getting a resistance reading between the plug caps on 1 and 4. I traced it to an apparently faulty plug cap. I can't get a resistance reading through it. I will try and get hold of one and see if this solves the problem.

[Joff]

I've been having a look at the spark plug cap and I'm learning...
I removed the outer rubber covering to have a closer look at the cap. I originally thought that it was just a straight forward conductor but now I see there is a resistor inside the barrel. If you insert a screw driver in the plug end you can unscrew the end and remove the resistor. I discovered some dirt and corrosion in there. I have now cleaned it and reassembled. It now gives a resistance of 4.8 K Ohms which I believe to be correct. Hopefully this will help to solve the starting problem!

[clarkdw]

Thanks Joff. I didn't know that the caps could be disassembled and cleaned. One more thing on the "to do" list.

[Joff]

I had another go at the starting problem at the weekend. If you put a flat ended screw driver in the spark plug end of the spark plug cap you can unscrew the end fitting (which clips on the plug) and access the resistor. I then cleaned all the resistors and end fittings one at a time (so they didn't get mixed up). After refitting them, the bike started first time and everytime after that first time (Ive almost certainly jinxed it now). I don't think its ever been this easy to start. I don't know if all the spark plug caps are like mine, but it seems to have transformed the bike. I guess the corrosion (which was worst on the two outer cylinders 1 and 4) was leading to a weak spark as suggest in the discussion.