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I bought my 1100 Silverado a few years back from a guy at work that bought it new. I think he kept up the maintenance religiously but the bike sat out a lot outside motels while he was out of town on jobs. He wanted to get rid of it more than I wanted to buy it so I got a good deal on it. I went through the normal progression of our addiction, drilling out the stock exhaust baffle worked for me for a while, but ended up with Cobra Longshots which required more air and fuel. I mulled over a homemade Pods Kit but decided to mod the air box instead. I chopped a rectangle out of the top of the stock airbox and laid in a K&N YA-1602-U designed for the XV1700PC Road Star Warrior 2002-2005, figuring if it would flow enough for a XV1700 it ought to flow enough for a 1100. I used the Wiki and other guidance I found here to work the carbs, ending up bumping both main jets to 145s. I was not very confident with my carb work but I was surprised when I test drove the bike. It had a little bog when I rolled on the throttle but it pulled long and hard. I figured soon I'd take it a get it dyno tuned to get the carbs just right. That was 3 years ago. This summer my starter clutch failed and I started to replace it myself. I pulled the tank, plugs, and left side covers and chickened out as I pondered jumping the flywheel off. I drove over to my local motorcycle repair shop where I had bought a few things, had a tire installed etc, and always came away with a good feeling. As a matter of fact the lady that owned the shop had owned a V-Star before her Harley, and the mechanic that came in from the attached shop had a V-star outside. So I drove over and I told her I had taken it apart and put it back together and she quoted me to replace the starter clutch.
I bough an oil filter from her and told her I would change the filter since you have to remove the exhaust to replace. I put it all back together finger tight and loaded it on my trailer, and carried it to the shop. A week later (while I was on vacation) she called me and said the starter clutch was done but the bike was running poorly and probably the carbs were gummed up. She wanted to work the carbs. I knew the carbs were not gummed up but I figured the mechanic did not think my carb tuning was up to his standards, so what the hey, go ahead work the carbs, whats another $200 bucks right. I told her I had modified the airbox and rejetted the carbs but she must not have told the mechanic. When I got back from vacation I stopped by and she said her mechanic told her you can not modify the airbox for these bike or they will never run right so he taped over my mod and jetted the carbs back to stock. I explained to her how everyone that put a full exhaust on these bikes somehow mods the airbox and jets the carbs. After I left I called the shop and told them I was going to come back by and listen to my bike to see if maybe he had the timing off or something. When I got there he told me he had just found the plugs loose and plug wire just laying on the plugs...I had left them this way but he should have had them out cranking the engine around. He said he would pull the carbs and return them to how I had them and balance the carbs. I went out of town for another week and when I returned Tuesday I went by, she told me the mechanic had worked the carbs and put the airbox back how I had it. I paid the bill and left, but the bike was stumbling a lot. I took a back road where I could run it up and down and it would absolutely not take throttle and WOT at 65 in 4th gear sounded like the rev limiter...totally falling on it's face. I took it back to her and she said she would have another mechanic go over it. Two days later I picked it up today and it was still running poorly, when I took it back to the shop they refunded the $200 carb repair and said they have done all they can do. I brought it home and changed the plugs in case one of them had got dropped, put a gallon of gas in it and drove it but it still runs like crap. Now I need to take it to someone that can figure out what is going on and correct it.
 

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the only thing I can comment on is the mods you made to the airbox

the carbs need the airbox where it is and like it is because the carbs create a standing pulse of fuel/air fog in the air box when the engine is running.

If you cut the airbox open and stuffed some airfilter in there, you have changed the dynamics of the airflow on the intake side of the carbs.

To explain this another way, if the shape and volume of the air box was not necessary, there would just be a tube or hose going from the intake of the carbs to the outlet of the air filter enclosure. The airbox space and volume is necessary.

People make the same mistake when they try to run or test or tune the bike with the airbox unconnected, or when they put those cool looking air filters right on the intake of a carb. The engine will not run right if there is no place for that standing pulse of mist (where the airbox is suppose to be, with nothing in it). There are some really terrible videos on youtube about modifying and maintaining your motorcycle, some of them will outright cause you to destroy your engine or damage other parts of your bike, and there is no one there to correct those videos or force youtube to take them down. A lot of bikes end up being basket cases as a result.

you said the airbox mod and new jets made the bike bog down, and you rode it that way for three years. What did your plugs look like after riding it that way, lean - rich - or normal?

Im afraid you have ventured into a sort of no-mans land: you made some mods to your motorcycle that are not standard or conventional, it was running but was a bit off, then you took it to a regular mechanic to do the starter clutch repair, with things only finger tight and the spark plugs not torqued down or plugged in all the way. When this happens the mechanic does not know what you have done to the bike, so when its not running right he cant assume what has been messed with or altered and what is still stock.

If you step back and look at this from the shop mechanic's perspective, the bike was not running fine when you took it in. The starter clutch had failed, the plugs were not screwed in, it was not running at all. The mechanic never saw the bike running when you took it in - just trying to be fair on both sides. after the mechanic fixed the starter clutch "they called and said the starter clutch was done but the bike was running poorly". He knows how the bike is suppose to run.

Its easy to check the valve timing, you take the side covers off the heads and see if the timing marks line up with the timing mark on the crankshaft. The odds that an experienced mechanic would replace the starter clutch and jump the chain on the valve timing are pretty slim, but again that would be an easy thing to check.

I would seriously consider replacing your airbox mod any of the aftermarket intake pods that have a proven track record. Then you will know what jet sizes are needed for that intake and your aftermarket exhaust, and how far to turn the PMscrews out as a starting point to tune the carbs for the aftermarket intake pods and exhaust.

I hope this does not sound like Im being critical of you personally. Sometimes people make mistakes or do things on their bikes that cause problems. If we focus on the issues with your bike Im sure we can help get it running perfectly.

I have to add: there is nothing wrong with trying things out, experimenting on your bike, trying things to save money when you need to, and finding clever ways to make your bike run better. The thing is you have to be willing to make mistakes, and sometimes to fail, and be willing to work backwards to find where it went wrong.
 

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Honestly, what i would do in your shoes, is re-learn how to work the carbs (since you did the job years ago and probably forgot what you had done to make it run just right). You were able to do it successfully the first time, so I'm sure you can again. If that doesn't work, reset everything back to stock. Stock jets, turns, airbox covered, etc. to get the bike working back to normal and then work your way back up again.
 

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Discussion Starter #7
Thanks for your reply, I am not trying to put this on the mechanic, I admit I shouldn't have left the plugs loose, but I also don't understand why when it was not running right, he did not pull plugs to diagnose. He would have found them loose. The plugs were light brown and not eroded after 3 years. The bike was running well enough to not be causing damage I can assure you. All he had to do was put the same jets and shims back, adjust PMS and balance. I gave them the data from the wiki for settings, after they said they would rejet it, but I'm guessing he disregarded. I just know it ran decent before it went to them, and now it doesn't.
 

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Yes when I get time I will pull the carbs, and relearn how to build them. Maybe he built them right and there is a wire pinched or a bad coil or something. By the way if the not modding the airbox is so important, how do the bikes with PODS ever run right?
 

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the pods are designed to maintain the volume of the airspace over the intake of the carbs, so that standing wave pulse of air/fuel has the room it needs

there are intakes for bikes that dont work well, but they look great - see the short stubby ones on vintage Honda 750/4 bikes a lot.
 

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Discussion Starter #10
the pods are designed to maintain the volume of the airspace over the intake of the carbs, so that standing wave pulse of air/fuel has the room it needs

there are intakes for bikes that dont work well, but they look great - see the short stubby ones on vintage Honda 750/4 bikes a lot.
I left the entire stock intake intact and laid in a K&N on the top of the airbox not stuffing some filter material down in the airbox. (I posted a pic in my Album I think). I fail to see how I interrupted the volume of air space overtop the carburetors. If anything I interrupted the turbulence that the air-fuel may have needed to mix. Maybe I'm wrong.
 

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I know I'm going to talk about the old Honda's, but it is still relevant. After reading many post about guys who switched from airboxes to pods, I bought my first cycle after 30yrs of not riding. Honda 900C with pods, I thought it ran pretty good, wrong. I was noticing that at idle take off it would bog down or die and then at 55 when going to pass it would bog down before take off. I slowly bought the original parts back and changed them as I got them. After putting on the original air box on I noticed idle take off was no problem and the 55 passing was great. With the air box in place a vacuum was formed to help the carb work right. If they could make a 200cc engine produce like a 1100 why would make something else. Most of the people who play with the factory setup really never get it tuned just right but what they can live with after they spent all that money and time to make a better bike.
 

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https://www.starbikeforums.com/forums/picture.php?albumid=6246&pictureid=19518

So last Thursday, facing another weekend without my bike, I decided to look into what was causing it to run like crap. I checked the fuel filter, emptied the gas tank, cleaned the petcock screen, checked for pinched wires and intake boots not installed correctly, but nothing jumped out so i pulled the carbs. I opened one carb up, verified there were two .020" washers and the plastic on the slide, and that the 145 main jet was installed. The idle air screw was set to 3-1/4 turns out, and I rolled that back to 3 turns. I was starting to get a sinking feeling in my gut that I had not found anything wrong and my effort were for nought. I started to put the float bowl back on and decided to use the new screws that had come with the kit the shop had bought. As I was sorting through the parts I noticed a used 145 jet in the box. Hmmm, they must have changed one...surely, or they had not put the right jet back in. When I opened the other carb I found no main jet installed! WTF, no wonder it sounded like I was hitting a rev limiter when I rolled WOT! I verified shims, installed a NEW 145 main jet I had, adjusted the idle air to 3 turns, and installed the carbs. The bike fired right up and a test drive resulted in much improvement. The next morning after a 10 mile or so ride I felt more confident, so I rode it to our farm in Carolina for the weekend, about 80 miles. I was smelling a little gas fumes behind my windshield which gave me some concern, and so the next morning while the bike was cool I pulled the air cleaner and tank to provide working clearance to adjust the idle air down to 2-1/2 turns. Later that day we rode 2 up for a nice 2 hour ride through the rolling back hills of northern NC / south central Virginia. My wife said she did not smell anything but I still was smelling some fumes behind my windshield. During this ride I filled up and had used 2.4 gallons in 116 miles. Thats like 48 MPG. The next morning I again backed down the idle air screws now to 2 turns, and we rode another couple of hours. I could no longer smell fumes so I can only suspect that the fumes were caused by a over rich condition in the air box being pushed out the K&N I had cobbled into the top of the air box. (see a picture of the mod in my album) I had to tweek that standing wave pulse of air/fuel KCW was so sure I had destroyed. We rode 65 miles 2 up and then I rode alone 80 miles home for a total of 144 miles. When I filled up I had used 2.82 gallons for 51 MPG. I'm not sure what kinda mileage these bikes are supposed to get but that seems pretty good to me. I still need to take it somewhere and have it dyno tuned and balanced but it is back to running like it did before the started clutch failed after 24K miles. Thanks for your support.
 

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with a windshield on an 1100, 51mpg is actually pretty good

I cant understand how the bike could run at all with a missing main jet. They come on in a sequence as you roll on the throttle, when the main jet was suppose to open I dont know what it would do with it missing? totally flood the cylinder with gas?

this is a new one
 

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with a windshield on an 1100, 51mpg is actually pretty good

I cant understand how the bike could run at all with a missing main jet. They come on in a sequence as you roll on the throttle, when the main jet was suppose to open I dont know what it would do with it missing? totally flood the cylinder with gas?

this is a new one
The wife and I together don't go much over 300 lbs so it was light loaded and we were enjoying the ride so we were in no hurry. On the trip home I ran a good while at 70 though.

When I picked it up it actually would fall on it's face with anything more than a little throttle. I rode it home and parked it. I'm sure It was washing down a cylinder the whole way.

Just glad to have my wings back.
 

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If we havent said this before, take the oil filler cap off and sniff your oil - doesnt take much gas dilution to thin out the oil
 
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