klr650
10-08-2005, 10:56 AM
I have a 89 zx750r F3.7200 mile Some times the bike runs good and some time it does not. I had the bike in for sevrice and told them the number two plug was carbon fouled.. They chandge the plugs and said they could not fine anything wrong with the bike. They set the carbs and everything checked out fine. After a couple a days it started running like grab. It does not do it all the time. Some time it feels like it running on three instead of four ,but then clears out and runs fine. Carbs have been clean nothing in the bowls, The tach some times reads right and some times the tach reads 2000more rpm then it should. When you turn the key to the on postion the tac neddle jumps once realy quick, thats how i know the tac will be reading wrong befor i start it up. This happens on and off.I can ride it a week strait and the tac will work fine, leave it sit for a couple days go to take it out again and the tach reads wrong. I check the batt its fine , the charging system is good. The bike runs great on some days and some days not. I check the coils they are fine. Any help would be great.
bigwater
10-08-2005, 11:52 AM
Does the problem follow the use/abuse of the bike? What I'm getting at is that if you're only experiencing this problem when the bike is fresh (ie: not running hot) you may be experiencing a problem with cracked rings that are allowing blowby at cooler temps. As the bike heats up, the rings expand, fill in the gaps, and it all runs good again. Cracked rings will allow oil into the combustion chamber and contribute to fouled plugs. Cracked rings will also cause the bike to seem like it's missing on a cylinder until it gets really warmed up.
As far as the tach jumping on you, that's a ghost in the machine. Does that bike have an electronic or a mechanical tach?
klr650
10-08-2005, 08:50 PM
[QUOTE=bigwater]Does the problem follow the use/abuse of the bike? What I'm getting at is that if you're only experiencing this problem when the bike is fresh (ie: not running hot) you may be experiencing a problem with cracked rings that are allowing blowby at cooler temps. As the bike heats up, the rings expand, fill in the gaps, and it all runs good again. Cracked rings will allow oil into the combustion chamber and contribute to fouled plugs. Cracked rings will also cause the bike to seem like it's missing on a cylinder until it gets really warmed up.
As far as the tach jumping on you, that's a ghost in the machine. Does that bike have an electronic or a mechanical tach?[/QUOTE
Mechanical tach
ruling out the rings since the bike runs great and does not burn oil the bike runs fine when hot or cold.
just once in great while it acts other wise it realy no big deal it just bugs the hell out of me.