Help with a Yamaha

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magnumdart

magnumdart

There is a bad moon on the rise.
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I have a Yamaha SECA 2 that will not run with the throttle opened up, just runs at idle. It seems to run ok at idle, although it seems a little high at 1100 rpm. The tach is probably not all that accurate. If you open the throttle quickly just a bit it will bog. If you slowly open the throttle it will start to run a little rough. If you continue to open the throttle past about 3000 rpm it will sputter and quickly die. If you open the throttle quickly from idle to wide open it makes no noise at all and dies instantly. It will idle for quite a few minutes if you turn the fuel valve off. In the morn I will check the fuel pump, timing, and coils. You can assume that everything is in good shape with new plugs,etc. The bike ran fine, was parked overnite, and the next mornnig it was screwed up from the moment it was started. As a precaution I will drain the fuel and put in fresh. I am completely unfamiliar with motorcycles so I'm open to suggestions of what else I should do or check. It is a 600 in-line four with four carbs.
 
I have a raptor 660 obviously a bit different but I have had a similar issue in the past. Usually changing out the spark plugs cures it.
 
sounds like the high speed orfice or jet as we call it has a little dirt in it clean it and it will be fine
 
jimjimjimmy said:
sounds like the high speed orfice or jet as we call it has a little dirt in it clean it and it will be fine
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Yep, sounds like your main jets are plugged, and you are running off of the pilots. I usually pull the bottom of the carbs off and run a piece of copper wire up through the holes. You need a real fine piece. Take some speaker wire and unravel it so that you have just one thread. Spray the crap out of everything with carb cleaner and put it back together. See if that won't fix it.
 
Let me ask will it rev with choke on? if so
I would start with checking the rubber o rings that seal the intake to the head.
 
Arco440 said:
Let me ask will it rev with choke on? if so
I would start with checking the rubber o rings that seal the intake to the head.
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I actually tried this and it just caused it to die all the quicker. I will be done with checking all these suggestions in three or four hours as I am doing three other vehicles all at the same time. Hopefully one or a combination of some of these ideas will cure this, and I will post results.
 
Was it parked where someone could have messed with it!. I've never seen one do anything like this instantly that wasn't electrical in nature! The coils could be breaking down under load, bad ground, how olds the battery! Before you get too carried away make sure the petcock is supplying enough fuel and use a timing light to make sure your fire ( on all plugs ) is consistant! Please remember that if you take the carbs off they will have to be synchronized to ever work properly again! ( Not Cheap ) If you changed the fuel as stated. it's got to be fuel ( supply ) or electrical. Feel free to pm me if necessary to walk you through anything you need! I have a synchronizer but I'm a long way from you!
 
You have water in your gas, at the bottom of each float bowl there is a tiny screw open one up at a time with the fuel **** off and drain out each carb. Now get a bottle of gas line deicer (this brakes down the water into small droplets) pore it into your gas tank.
Now fire up your bike.

Kenny
 
OK. Here are the final results. I pretty much took everyones suggestions. I did not remove the carbs, although I do have access to a syncronizer. Anyone who knows me, knows I will always start at the very basics. It pays off about 99 per cent of the time. So, I checked coils, OK, checked timing, OK, checked battery, OK, new plugs, dumped fuel tank, and filled with about a gallon of fuel and one whole can of seafoam. One part of the fuel line was a little questionable so I replaced all the fuel and vacuum lines. I took off the air cleaners and sprayed all the carbs clean and any of the orrifices I could see, and backsprayed the two vent tubes (?). I took the fuel pump out and cleaned it with carb cleaner. I shot carb cleaner back into the tank at the valve, through the vacuum and fuel openings. Then I checked the opperation of the throttle and choke. When I got it all together I started it. It ran a little ratty for a few seconds, and then it commenced to doing all the same things again. Well, needless to say I was somewhat taken aback. If it wasn't my first attempt at a jap bike I'd a burned it to the ground. So I went over to the shelf and got a can of ether. I slowly started opening the throttle so it wouldn't die and just sprayed the ether right at the air cleaners. It died. Not to be outdone I started it and began bringing it up to speed and sprayed just a little ether at it. It gained a litle rpm's without dying. Then, get this, it instantly reved to about 12 grand. I thought it was gonna explode. So whatever. It goes down the road good. Just a tad sluggish, and I am hoping that will improve once it gets a blast down the interstate. So thanks to all for great suggestions, and I'm off to get my town and country cooling fans spinning again.
 
Your main jets are definitely plugged the instant reving proved that. When the fuel got there it worked. By the way instead of ether use a squirt bottle with gas. It will work the same and save the rings. YOU HAVE TO take the carbs off to get them clean. Plus with your fooling around with that bike (I have had several secas) your plugs are fouled. Good luck!
 
Oh I read your last post again and didn't see that you got it to run. Run good carb cleaner through it.
 
Hemiroid said:
You have water in your gas, at the bottom of each float bowl there is a tiny screw open one up at a time with the fuel **** off and drain out each carb. Now get a bottle of gas line deicer (this brakes down the water into small droplets) pore it into your gas tank.
Now fire up your bike.

Kenny
Click to expand...

I have trouble with my bike running also so I took your sagestion, it now runs great. I am from now on going to run gas line deicer in my bike
and car. Thanks Hemiroid!!!!!! :prayer:
 
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