Intermittent tachometer

83 Seca 900. Anyone run into a tach that works when it wants to? Sometimes I start the bike and it seems fine or it seems like its 2 to 3000 rpm slow. Other times nothing at all. Just wondering if any common fixes before I dig in to have a look.

Thanks

 

Check connections or could be corrosion on the back of the tach. The other if you can open up cluster , know the 900 has a different gauge lay out if you can get access ,spray with contact cleaner behind face plate you should be able to see the windings of the tach . Hope this helps

 

This thread is for a mechanical tachometer, but the part about cleaning and lubricating the bearings applies to your tach.
Speedo and Tach dissection with pics

Other things to check is that the signal wire to the tach is clean and connected to the grey wire on the right hand (as you sit onthe bike) ignition coil.
Most of the connections for the gauge cluser are inside of the headlight bucket.

 

Thanks guys! This is a big help. Last Thursday my family and I were rear ended on the highway. Rolled us 3 times @65 mph. With some help from above we are all ok ,but it will be some time till I can get back to the Seca.

 

you have my thoughts and prayers. I hope all goes well for you and your family

 

Thanks XJ550H. Much appreciated. Wife and my 8yo daughter are bruised but doing well. I took the brunt of it. Couple heavy lacerations and a fractured foot ,but I'll be back on my bikes soon enough.

 

It looks like things could have turned out a lot worse. Glad you and the fam are OK.

 

Thanks k-moe

 

Yikes, glad to hear you are all okay. X2 on k-moes comment, amazing looking at that pic and hearing there were no major injuries.

 

Wow S10gto.....super glad you and the family will be OK! Sure hope you all heal up quickly and life returns to normal very soon!

When you get back to the XJ....I had a similar but maybe different problem on my 900. The tach just quit working completely. Disassembly, cleaning, and reassembly of the wiring harness connections in the headlight housing got my tach working again. Not certain which connector may have been the culprit, but I cleaned them all since I was in there.

 

Thanks everyone. As soon as I'm on my feet I will start with all the connectors. Being intermittent it's a good chance it will be fixed.

 

Ok I'm back. Bone in healed and I'm walking again. Took the bike out and it felt so good to be in the saddle again. Hurts to shift but pain of not riding is worse. Now time to get after that tach. Thanks again everyone .

 

Well I have check all connections but no luck. When I first turn on the key the tach jump to 1000 then back to 0. If I hit the kill switch with the key on the tach goes to 4000 and stays there. Thinking the tach is bad. Connections in cluster are clean and tight also. What do you think...tach toast? When it did work 2000rpm was 50mph. Shouldn't that be closer to 4000 by the way the engine sounds?

 

Probably a good assumption but first make absolutely sure it is wired correctly and that the ground and signal (Gy and Blk) wires are not reversed.

My only other thought to further isolate after verifying the wiring is it to disconnect the gray wire and see what happens. If the tach remains at zero we may not learn much, but if it jumps when the key is turned on the internal circuit card is likely defective. Another thought would be to disconnect the TCI connectors and see how it behaves with the key on and kill switch as you describe above.

 

Thank you. Will do! If I don't find any issues heck I'll just throw a tach at it and see what happens. I will be sure to update to help grow this wealth of information here at XJ bikes.

 

Update. I checked everything and all looked good so I threw a $40 ebay used tach at it.....BINGO! All is good now!

 

Been riding the 900 alot lately looking for a new truck for the wife. Tach is working great! I had a feeling when the old one did decide to work it was wrong. Looks correct now. 50 mph is just over 3000rpm in 5th. Not 2000 as the original tach thought.

Love this 900. So smooth and just ridiculously XJ reliable!