96 RSTD Adjusting Pilot Jets?

[ToyOdie]

I have been reading several threads on exhaust poping on deceleration. I have had the problem since I bought the bike over two years ago. It seems to have gotten worse over the last few months, so I think I've decided to try to fix it once and for all. I have already run a can of Seafoam through the carbs over the last 2 tanks of gas. This has usually helped but never eliminated all the poping. This time it didn't seem to do much at all. I have checked for exhaust leaks and found none. I have done a carb sync with no change. My next step based on my reading is to clean/adjust the Pilot Jets. I have found several threads explaining in detail the proceedure. I am confident I can do the job except for one thing. I have a 96 RSTD and the carbs are different from the ones discribed for newer Ventures and RSTDs. The adjustment doen't look like it's accessable from the outside of the float bowl. I don't see anywhere there is a "brass cap" to remove to gain access for the adjustment. In the thread it says I should find it next to or near the float drain. I don't seem to see anything. At the YamahaPartsHouse.com site there is a parts breakdown that shows the difference when you look at a 96 compared to an 07 carb. The carbs on the 96 through 2000 look to be the same. Can someone help me with the proceedure and or location of the access.

[joboo]

this is a pic of the carbs on my 96 RSTC should be the same carbs. There are what looks like three holes on the flat portion, just under the round diaphragm covers. The center hole would be covered with the brass plug had mine not been removed. You can barely see the screw down the center hole on each one.

[ToyOdie]

Thanks!!! Obviously I was looking in the wrong place. I was under the impression that they were in the float bowl cover someplace near the drain. I'll take a look when I get home.

[ToyOdie]

OK...so I went home on my lunch break to look at my carbs. The caps are still in. Is there an easy way to remove them. I tried to pull them with a small screw and it didn't work. I also tried a small screw driver on the edge. I just don't want to damage anything in the process.

[RSTDdog]

Typically you drill a small hole in them and insert a sheet metal screw and pull them out. Wrap tape on the drill bit to limit how far it goes. try a #6 or a #8 screw.

 

Have you ever had the carbs off and inspected them internally?

 

You could have a partially plugged pilot jet. This is the actually jet inside the carburetor. The screws you are accessing are the mixture screws that adjust the the amount of fuel through the pilot circuit. While richening these screws can help, the effect will be minimal or ineffective if the jet inside the carburetor itself is clogged.

 

RSTDdog

[twigg]

OK...so I went home on my lunch break to look at my carbs. The caps are still in. Is there an easy way to remove them. I tried to pull them with a small screw and it didn't work. I also tried a small screw driver on the edge. I just don't want to damage anything in the process.

 

I'd be reluctant to remove them at this point.

 

While it is fair to say that the factory set them up a little on the lean side, then sealed them, they should not have been popping in the exhaust.

 

Removing the caps and turning each screw back maybe 1/4 turn might help, but it is more likely that the popping is caused by air getting in, rather than the mixture setting.

 

There are not very many places air can get in, so it's sometimes fairly easy to work it out.

 

Favourite places are the header pipe gaskets and the carburetor butterfly shaft seals. .. and the carb to intake holders.

 

I'm not saying that adjusting the idle mixture will not solve the problem ... but it might not, and it might not be the best place to start, is all.

[ToyOdie]

I think my plan of attack is to remove the caps and make a minor adjustment to see if the RPM changes. If not, I'll remove the carbs and clean the pilot jets. I don't want to open the carbs if I don't need to. I have pulled them but I have never been inside. If I do have to open the float bowls, can I reuse the cover o-ring? It sounds like a stupid question, but I'm not sure if I can get them locally and I'll hold off untill I can order them if they can't be reused. Thanks for all the help. I don't think I would own this bike without you guys.

[joboo]

Unfortunately Toy, this is one of those things that you won't know till you get em off. I can tell you that I have never replaced my float bowl orings and they have been on and off somewhere near 50 times. I use some engine oil on my finger to coat them lightly prior to putting them on. I know there are lots of guys here that will tell you NOT to take off the carbs or only do it as a last resort. I completely understand but I think if you are at all mechanically inclined it is not that difficult. The reward is that you become much more familiar with your machine, you don't have to take it to the shop for every hiccup, it is mostly a lot cheaper and the rewarding feeling is great. The other benefits are that you can see for yourself if something needs fixed or replaced. I am guessing that you have never had the tank off, therefore you haven't seen the airfilter or know the condition of any of the hoses or clips or rubber boots other than what you can see peering in from the sides. I personally would never try to take the float bowls off while the carbs were still on the bike, they just aren't that accessible. BTW if you do decide to clean those pilots, count the turns very carefully back to seated position and then take them out for each one so you will know the factory settings. One more thing, my 81 never popped but my 96 has always had some decel popping since it was new, after everything that has ever been done to it, no shop or me has ever made that change or discovered any reason, The main suggestions over the years was to rejet with a different size and to do the slider shims, but I have gotten to where I kinda like the sound.

[twigg]

Unfortunately Toy, this is one of those things that you won't know till you get em off. I can tell you that I have never replaced my float bowl orings and they have been on and off somewhere near 50 times. I use some engine oil on my finger to coat them lightly prior to putting them on. I know there are lots of guys here that will tell you NOT to take off the carbs or only do it as a last resort. I completely understand but I think if you are at all mechanically inclined it is not that difficult. The reward is that you become much more familiar with your machine, you don't have to take it to the shop for every hiccup, it is mostly a lot cheaper and the rewarding feeling is great. The other benefits are that you can see for yourself if something needs fixed or replaced. I am guessing that you have never had the tank off, therefore you haven't seen the airfilter or know the condition of any of the hoses or clips or rubber boots other than what you can see peering in from the sides. I personally would never try to take the float bowls off while the carbs were still on the bike, they just aren't that accessible. BTW if you do decide to clean those pilots, count the turns very carefully back to seated position and then take them out for each one so you will know the factory settings. One more thing, my 81 never popped but my 96 has always had some decel popping since it was new, after everything that has ever been done to it, no shop or me has ever made that change or discovered any reason, The main suggestions over the years was to rejet with a different size and to do the slider shims, but I have gotten to where I kinda like the sound.

 

Some exhaust popping is almost an inevitable result of a lean set-up. Manufacturers set bike up as lean as they dare to make it easier to comply with emissions laws. It probably didn't pop when it left the factory, but time, mileage and tiny air leaks soon get it popping

 

It is actually completely harmless, even though it indicates a condition that could be resolved if you wanted to.

[ToyOdie]

Well I removed the brass caps by drilling and using a sheet metal screw. It wasn't that bad. Then I marked the original settings and turned each screw in to find the factory setting. I was surprised at how different each one was. I then adjusted 3 and 4 out an additional 1/4 turn and tried it. It seemed a little better so I continued adjusting each one until the popping was reduced to as little as I could get. I still need to check the sync. I'll ride it a while to see how it runs. Then I'll decide if I'm going into the carbs for a proper cleaning. I'm also going to run some more SeaFoam through it for good measure.

 

Thanks for the help and moral support.

[ToyOdie]

Ok, I removed and cleaned the carb's. I found the #3 and #4 carbs had the most dirt. These are before and after pic's. While I was thereI set the floats just like the manual said. I only had to adjust #3. When I got it back together I sync'ed the carbs. I'll have to admit the it was running like crap. It was the poping at idle and it was worse on deceleration. So I continued to adjust the mixtures. That wasn't making much differnence so I removed each mixture screw and shot a little carb cleaner in the hole. Then I put the mix screw back to the original setting I recorded before I started messing with it. The poping at idle went away and the engine smoothed out. I still had some poping on deceleration, so I adjusted the mixture screws one at a time and I just about have ALL the poping gone. Now it only pops under hard deceleration.