Virago's

[PBJ]

Hey Gang,

 

as some know last summer i helped my friend, Tailfeather here on the forum to buy a 85 Yamaha Virago 1100. One cylinder wasn't running right and i was asking here for some advice and got a lot of good stuff. Thanks again to Clive and Mike Eusa!.

 

So here's an update. First we had a torn diaphragm so we bought a used set of carbs we found to get one. ( It was actually cheaper than just buying a new diaphragm.) We also pulled the needles out of it and found they were also different. Along with that we found that the previous owner had bent the needle tang on the float for some reason we could not figure.

 

So we replaced the needles and the o ring gaskets to the carbs. We put it all back together and the bike ran great. It started held idle, no flooding of the carbs, I took it out ran it problem solved. Hurrah.

 

I couple of days later my son takes the bike out for a second test. On the way the rear cylinder floods and fails, the bike dies and we end up having to walk it home. ( luckily he wasn't too far away and it was mostly down hill from where he was.)

 

I call Mike( EUSA1) for more advice and this time we do a complete rebuild on both carbs. Well worth we feel with the new ethanol out there. We put it all together and the bike starts belching gas out of the carbs either the front or back we can't seem to balance them.

 

We learn that the after market kits Yamaha now sells are for the Virago's with-OUT fuel pumps. Which is odd because the Mikuni carbs models all had fuel pumps. But it seems the pump over powers the seat/needle and forces it open under pressure.

 

I call a local dealer, Sodus Snow Sleds in Sodus NY. He had seen this before. His answer was to remove the fuel pump. It seems that the pressure from the tank above the carbs is enough to feed the carbs with out the pump. So we remove it and the bike runs great. We take it out run it around town, then out on the high way up to 80 and it runs fantastic.

 

We've installed two additonal fuel filters into the system besides the cleanable one already on the bike because we keep finding this unknown red substance in the fuel. We suspect it might be a gas tank liner of some kind. It looks like there is also a white tank liner in there. ( I hate that stuff) . Anyway I delivered the bike to Tailfeather and found that it excelerates great nice and strong, idles good but now when I get it up over 65 I start to lose the back cylinder. I think its starving from the lack of pressure from the pump. But it holds at 60 great.

 

I didn't check the fuel filters to make sure they aren't plugged up with crude again but i will in a couple of weeks. But the bike does run strong and can still get up to eighty or higher it just drains the bowl faster than it can refill apparently.

 

So there we stand. Any more ideas or suggestions? I'd love to hear what you all think? PB&J

[camos]

The rear cylinder runs hotter because it does not get as much airflow as the front one. The needles in the carbs are supposed to be different sizes to supply more fuel to to help cool the back cylinder. I've read of people changing to a gravity feed when their fuel pump quits. Don't know much about it but seem to recall doing that only sort works and getting down below a 1/4 tank will also cause starvation to the back carb, I think, which will cause it to cut out. Make sure the fuel line is routed straight as possible to aid in fuel flow.

 

I've never heard of this issue with carb kits, perhaps Yamaha is clearing out old stock that they can't get rid of any other way. It might be Yamaha dealers or just a dealer doing it though. I'd be looking for the proper kit.