Hello anyone around the San Jose Ca area willing to help out? I am trying to fire up my 91 cbr this weekend. Just got the new battery and figured it was time to try and fire this beast up after 7 plus years of it sitting in pieces. But a tad worried about how to go about it. Anyone willing to come by and help kick the tires with me would be cool.

 

Other side of the world Scott, so won't be able to kick the tyres with you unfortunately.

I can offer some help via the forum though.

Starting a long dormant bike can be fun, or the headache from hell. A few things to consider.

If it was in pieces, how many?

Did you rebuild the engine and double check the timing is correct? Did you rebuild the carbys? Did you clean out the fuel tank and and put an in-line filter in between the tank and carbys? If you are satisfied that the engine turns over without binding valves, and you have fresh fuel available, new plugs, clean or new air filter and fresh oil in the engine, you are ready to start.

Ensure the battery for the bike is FULLY CHARGED.
With the kill switch set to off and the fuel off, hit the starter, let it run until the oil pressure light goes out.
Switch the fuel on, kill switch move to run, put the 'choke' on FULLY and again hit the starter. Don't be tempted to rotate the throttle. Do this in 10 second time frames. I.e. don't run the starter for more than 10 seconds in one go.

It may need a tiny kick along by spraying some starter aerosol directly into the air box (filter removed), but be cautious with this.

It's just a combination of air/fuel and spark.

We're here to help if one of the three isn't in the right place at the right time!

Good luck with it.

Cheers, SB

 

Motor was not in pieces just mostly the body. I have some of the body but keeping it all off until I do some test firing. Gas tank is in great shape (minus a dent here or there) But inside Clean. I have the tank off and will just run fuel in a small bottle to run it for little bits. I'll try with the old spark plugs at first and see what she does. I know it'll need a full tune up once I am ready to fully run the bike. But just trying to gauge what I need by test firing it this weekend. Mostly wanting to check wiring and if I can get spark. Oil in the bike looks new but will change that once I'm in the tune up phase. I did hand roll the bike and checked gears and clutch seems good after some banging on the shift leveler. It didn't want to shift at first but good smooth now. Love the list you put down. I'll go over that stuff this weekend as well. This is really a barn find. 7 years of not running so it's going to be fun bringing it back to life.

 

Here's one I prepared earlier

It appears that my bike was very much like yours - but 15 years in limbo. Primarily putting all the pieces (including carbs) back together and starting it.

https://www.youtube.com/watch?v=ql978R50lFc

Best of luck Scott, it's a great feeling to get them going after a big slumber.

Cheers, SB

 

Sorry I'm in Ohio but you really got some good advice there.

Keep us posted.

 

OK test one done. Put new battery in. Turned key everything lights up. Turned run on and hit starter. Made a spinning grinding sound and not turning the motor over. Put bike in gear push rolled it to hear if pistons were moving and could move it and pistons sound free. Tried to put back into N and Nope can shift between two gears but will not go more. Thinking the tranny is toast.

 

This JUST happened to me last week, so before you assume it's a clutch/trans problem, remove and clean/lube/reinstall the shifter linkage first (it's easy to do and doesn't take long). Mine had a sudden bout of finickiness and after doing those things it was better, but still needed a good 1/2 mile or so of actual engine running and shifting before it was back to normal. If this thing has been apart for a while it might just need to go. Sometimes neutral is hard to find on these transmissions on a good day or when they're hot, OR (apparently) when they just haven't felt some love in a while.

 

Whoa! Ok clear a few things up for me please.

1. When in gear (not trying to start it) and you pushed the bike back and forward, it turned over the motor? You could 'feel' the compression in the cylinders?

2. When you tried to start it, it was out of gear and you heard the graunching sounds but the engine wasn't turning over?

If the above are both true, I'm suspecting something in the starter motor/starter clutch/alternator damper area.

Cheers, SB

 

Yes to both.

First try I turned Key on got all the lights up and Neutral light was lit. After hearing a odd sound of Free spinning and kinda a soft grinding sound I stopped. 5sec or so. I did try a couple times to listen to the sound of the starter to try to figure it out.

I shifted it into 2nd and tried to roll the bike in gear without starting it to see if the tire would turn the motor over while in gear. It moved was hard but could feel the motor turning over and could hear the pistons trying to compress air.

I shifted it back into neutral and tried the starter again. Still the same sound and not trying to spin the motor over. I then shifted it back into 2nd pushed the bike back a couple feet to make sure the motor was free while in gear. Again motor felt fine.

I then tried to shift it back into neutral but couldn't I would shift between two gears but not into neutral so I'm kinda lost as what gear it's gotten stuck in. (got frustrated and might have shifted it into 6th but can't get it to down shift.)

Now I did look up the problem in the user manual and the trouble shooting really wasn't helpful. I figure it has to be the starter or (gear/chain) between the two. I'll be pulling the starter first and seeing if the starter spins out of the bike. I'll also look to see if something broke and might have dropped into the tranny (blocking it from shifting)
The starter looks like a bear to pull out but I really have no choice at this point then to pull it.
Does this Motor use a chain from the starter to turn over the motor or is it gear to gear? If it's chain maybe (hoping) the chain has to much slack and dropped off the gear and is hanging up the tranny.

 

Hey Scott,

Keep with it and it'll be solved.

Ok, so I'm reasonably sure it's in the starter clutch/alternator damper area. It is a chain drive from that shaft (has the alternator/starter clutch/aternator damper) hanging off it. It's not too difficult to remove the starter, so get that out first and test it.

Then the fun begins. We have to determine if it's the chain between the alternator shaft/crank or the starter clutch or alternator damper.

All do-able with the engine in the bike unless the chain has slipped a tooth or two.

Cheers, SB