Does the 1300 gen 1.2 have YICS?

[CaseyJ955]

I have read two versions of YICS on the 1300 Gen 1.2 and one version says it did not come on the 1300.

 

I pulled the side panels off and I cant see anything, was it supposed to be there?

 

I'm trying to chase down why I'm getting a high of about 25mpg and an occasional bucking/surging/carb backfiring just after operating temp is reached. YICS came to mind as a possible culprit on an otherwise decent running bike.

[utadventure]

I don't believe any of the 1st gen 1300s had YICS.

 

It's possible that your air box isn't seated completely or the air boots are cracked. You may want to spray around the boots and see if you get an increase in rpms. This will indicate an air leak.

 

You will also want to check your diaphrams and make sure there aren't holes.

 

Dave

[yamagrl]

I have read two versions of YICS on the 1300 Gen 1.2 and one version says it did not come on the 1300.

 

I pulled the side panels off and I cant see anything, was it supposed to be there?

 

I'm trying to chase down why I'm getting a high of about 25mpg and an occasional bucking/surging/carb backfiring just after operating temp is reached. YICS came to mind as a possible culprit on an otherwise decent running bike.

 

No. The YICS is only on the Mk1 (Gen 1.1) 1200s 83,84,85.

 

Low mpg can be caused by a number of issues but it does kinda sound like a vacuum leak. That's about the easiest thing to make sure is correct. You certainly do not want to start looking elsewhere until you are sure there is no vacuum leaks and the airbox and filter is properly installed an seated.

 

First off just do a really good inspection of the carb, airbox, lines, etc. everything you can see and feel and try to move.

 

Then you can start it up lightly spray some starting fluid around the carb boots, lines, etc. The rpms will go up if the starting fluid is sucked in a vacuum leak.

 

Be Very Careful when spraying starting fluid around the engine! Just use little pst, pst, pst shots.

[Flyinfool]

Also in the realm of the cheap and easy to check.

Make sure you are running on all 4 cylinders. these bikes run amazingly well on 3 but the gas mileage drops way off.

From cold start the bike and feel the headers right at the head, they should all heat up at the same rate, careful they heat up fast.

[CaseyJ955]

Thanks guys. I'll start with checking for a vac leak and of course the mom-and-dad-were-first-cousins downpipe spit test to make sure it's hitting on all fours. When my Vmax dropped a cyl I was still all over the north hills just thinking it was a little down on power so I know they dont suffer as one would think when one pot is dragging it's feet. I went for a good run and checked for hot brakes and nothing there to suggest any dragging.

 

I had planned to pull the carbs and set float levels, check jetting, diaphrams and needle position but if I can do a wet float level check with the carbs in place then I'll just do that and slide the diaphragms out and check that and needles. I remember something about the needle jets wearing out and trashing MPG as well. It looks like carb removal is a PITA compared to the Vmax carbs but I know float levels are critical for CV carbs. I'm glad there is no YICS to hassle with. The only ridability issues I have noticed is when I hot start the starter motor works fine but I sometimes have to blip the throttle a little to get it to light up and the missing/chugging/bucking/surging/coughing always happens in the same place as I'm rolling into town so the same operating temperature. If I grab the loud handle and do a couple WOT bursts it subsides and does not reappear until the following day, same place/same time.

 

I have to go to work tomorrow for a week and when I get back I'll do this and the forks/bearings/springs/tires so I can maybe do a Yellowstone/Tetons/MT/WY thing before the roads ice over, I'm itching to put this thing to the road test! All the fork parts are here and the tires should be here today. I ordered the E3s from Dennis Kirk for $270 shipped.

 

Thanks once again folks!

[yamagrl]

Thanks guys. I'll start with checking for a vac leak and of course the mom-and-dad-were-first-cousins downpipe spit test to make sure it's hitting on all fours. When my Vmax dropped a cyl I was still all over the north hills just thinking it was a little down on power so I know they dont suffer as one would think when one pot is dragging it's feet. I went for a good run and checked for hot brakes and nothing there to suggest any dragging.

 

I had planned to pull the carbs and set float levels, check jetting, diaphrams and needle position but if I can do a wet float level check with the carbs in place then I'll just do that and slide the diaphragms out and check that and needles. I remember something about the needle jets wearing out and trashing MPG as well. It looks like carb removal is a PITA compared to the Vmax carbs but I know float levels are critical for CV carbs. I'm glad there is no YICS to hassle with. The only ridability issues I have noticed is when I hot start the starter motor works fine but I sometimes have to blip the throttle a little to get it to light up and the missing/chugging/bucking/surging/coughing always happens in the same place as I'm rolling into town so the same operating temperature. If I grab the loud handle and do a couple WOT bursts it subsides and does not reappear until the following day, same place/same time.

 

I have to go to work tomorrow for a week and when I get back I'll do this and the forks/bearings/springs/tires so I can maybe do a Yellowstone/Tetons/MT/WY thing before the roads ice over, I'm itching to put this thing to the road test! All the fork parts are here and the tires should be here today. I ordered the E3s from Dennis Kirk for $270 shipped.

 

Thanks once again folks!

 

Wet float level is pretty easy to do. Here's a screenshot of page 5-9 in 86-93 manual. If you've done it on a VMX it's the same thing. I personally have not done it on a VMX but I've seen it in videos.

 

I just use clear vinyl hose 1/4 id. I think I had to heat the 1/4 hose up a bit and force in a #2 Phillips to stretch it out a bit to get it to fit over the drain hose. I put 2 marks on the hose 16 mm apart. I also filed a line on the karber8er body and diaphragm cover.

 

I also think it's best to set all of the levels on either the back side or the front side of the diaphragm cover. I think if the carb rack is not perfectly level front to back then the levels will be different based on whether the reading was measured on the forward side or the rearward side.

[cowpuc]

Check resistance on your plug caps too..

[bongobobny]

YUP!! Ditto to what the Pucster says!!

[CaseyJ955]

Check resistance on your plug caps too..

 

By plug caps do you mean that lil' nub at the tip that needs to be screwed off for some systems?

Im going to do COPs but just not yet, I just dropped like $600 on parts and tires so ill do that resistance check first and save the COPs for a winter project. Of course it lacks the Vmax power but it doesnt feel like Im missing a cyl. When I whack the throttle it boogies. Im at work for the next 7/days so I have plenty of time to read and think about what to do next.

[CaseyJ955]

Wet float level is pretty easy to do. Here's a screenshot of page 5-9 in 86-93 manual. If you've done it on a VMX it's the same thing. I personally have not done it on a VMX but I've seen it in videos.

 

I just use clear vinyl hose 1/4 id. I think I had to heat the 1/4 hose up a bit and force in a #2 Phillips to stretch it out a bit to get it to fit over the drain hose. I put 2 marks on the hose 16 mm apart. I also filed a line on the karber8er body and diaphragm cover.

 

I also think it's best to set all of the levels on either the back side or the front side of the diaphragm cover. I think if the carb rack is not perfectly level front to back then the levels will be different based on whether the reading was measured on the forward side or the rearward side.

[ATTACH=CONFIG]107195[/ATTACH]

 

Thank you! That is the first check ill do after I get the forks, tires and head bearings sorted. It should be a pretty full day of tweeking and dialing everything in. This chart will come in very handy.

[yamagrl]

Thank you! That is the first check ill do after I get the forks, tires and head bearings sorted. It should be a pretty full day of tweeking and dialing everything in. This chart will come in very handy.

 

Here's the manual http://www.venturerider.org/forum/showthread.php?3384-First-Gen-Service-Manuals