New guy problems... 1st bike is a project!

[blitz]

Hello all...

 

I'm sure glad I found this site! Up front info I picked up a 1987 Venture 1300 that's been sitting for 4 years very cheap. Its my 1st bike & bike project. I know my way around an engine under a hood but very insecure when it comes to this. Now for the problem.... It took little effort to awaken the beast and took it for a short trip of less than a mile. It ran rough but still run. So now that I knew the engine was good I started the fixing process. Knowing the carbs were going to need cleaned, I removed the carbs and removed the bowls, floats, all jets that I seen and soaked them over night in seafoam. the next day I blew air through every hole I seen and made sure it blew out somewhere else and passage ways were open. In the process of putting it back together I broke a big jet that screws down in the needle guide??? Anyway I looked up the part and what I could find said it was the main jet.... I order new ones off JC Whitney and replaced them but they looked completely different than the originals. (PICS BELOW) I put everything back together and moved over to the diaphragm and slides. I noticed right away there was 4 holes in all four diaphragms as though they were meant to be there. The holes were in like a 4 corner design. Seeing the prices of these diaphragms and not wanting to dump a ton of money I googled solutions and found that some say they had great results with liquid electrical tape because its flexible. So I closed the holes with it. Now all back together and on the bike the bike starts very easy and to my ears the idle sounds clean and healthy. BUT... as soon as you attempt to throttle it up and bogs down and cuts out. When choked the rpms will rise but when trying to use the throttle it just bogs and dies! I been trying to figure this out for 2 weeks now even taking the carbs apart 2 more times making sure I didn't screw something up. Need help badly..... The only thing different between now and when I had it started and running down the road is the diaphragm holes closed with liquid electrical tape and the new jets.. Any and all advice would be much appreciated!! Pics below show bike, carbs and the difference in the new and old jets.

 

 

[bongobobny]

OK first question, are you trying to run it without the airbox properly installed???

 

Have you tried sync'ing the carbs?

[blitz]

Air box fully installed.... synced using the no sync guage method showed in YouTube vids from this site.

[snyper316]

Question????? Is this before or after you cleaned them?

[snyper316]

And the other question when you took them apart to clean up the orings real good I replaced all mine with a later year or different model im wanting to say i used the vmax orings and gaskets it kinda sounds like a problem i had at first when i did my first clean and put it all back together and come to find out I had broken enricher valve gaskets I know it sounds odd but once i got the kit and replaced gaskets and orings but my carbs looked like that at one time till cleaned them up... o and one more thing see if you see any slight cracks in your slides..

[bongobobny]

OK next question, with airbox off and looking down at the slides, when you rev it up, do all 4 slides "do the dance" in unison?

 

Also, as Snyper asked, how was it accelerating prior to first disassembly??

 

Check all vacuum hoses and caps for possible air leaks. Also, when you reassembled the carbs, did you reassemble with barb bodies on a flat surface? Perhaps one of the bodies is raised which may cause a leak at the base where they mount onto the boots. And, speaking of the boots, are all the clamps tight? Hey, just throwing out possibilities here..

[bongobobny]

Also, there is an EXCELLENT DVD you can buy from a gentleman named Damon Ferraiulo on rebuilding our carburettors! Although the video is on the VMax carbs, they are basically the same as ours, and except for some different jets, which he does briefly mention, they tear down and rebuild and set up exactly the same. Many of us own this video and swear by it! Here's a link to a thread here with the information on how to purchase one, WELL worth the small cost!!

 

http://www.venturerider.org/forum/showthread.php?84030-DVD-of-1st-gen-motor-amp-carb-rebuild-process-purchase-info

[blitz]

This is after I cleaned them.... before I cleaned them it ran rough but good enough to take a short road test. When the bike is at idle right now the 2 back carb slides are dancing very well, the front right slide is much slower and the front left does not move until throttle is applied. I replaced the O-rings but not the gaskets. The carbs are flat and fully mount to bottom boots. No visible cracks in slides. I will check for the air leaks asap! Any suggestions is appreciated

[bongobobny]

Buy the video I just mentioned above, you will be glad you did! Sounds like something did not get reassembled right or there is still a jet somewhere clogged, etc. These carbs are actually quite complex with several "circuits" depending on operating condition, i.e idle, higher RPM's, choke, etc.

[snyper316]

Go to youtube and look for yamaha venture but at idle my slides do not move when i throttle to i believe its 1500 or so rpm they start to move and all should move in unison and at cracked wide open they should also be wide open but in order to run good at 3500 rpms they all need to be pretty spot on so i would say you really should look thru the forum and get the Diaphragms replaces i am thinking you get a hole set for $50 unless you have cracked slide.. but i wished I had this video everyone is talking about..I have done carb rebuilds many of times but these Mikunu Carbs are way different then what I have dealt with in the past..

[blitz]

Im going to chreck into the video mentioned.... I looked around for diaphragms and have not seen any for less than $30 a piece! But they definitely need replaced. Nobody has commented in the jets I replaced and how different they are from the ones that came out? So I'm guessing they are ok?? Would the diaphragms cause the problem I'm having?

[blitz]

Also where is the best place to get the gaskets that were mentioned?

[snyper316]

Im hijacking your thread Now WHAT HE JUST SAID lol I actually want to rebuild my carbs completely so where is the best place to find the jets and such tired of fighting the ones in my carbs....

[snyper316]

But you may want to search ebay a little bit because that is just for one carb and i ordered one for all the carbs and cost me 85.00 all together

http://www.ebay.com/itm/4-K-L-86-07-VMAX-CARB-KITS-V-MAX-83-93-XVZ13-VENTURE-VENTURE-ROYALE-carburetor-/361517049733?hash=item542c186785 actually this is better it comes with all four carb kits

[bongobobny]

Here's a start...

 

http://www.ebay.com/itm/Yamaha-K-L-Carburetor-Carb-Rebuild-Repair-Kit-NEW-XVZ-1300-XVZ1300-Star-Venture-/310978128892?hash=item4867bdabfc:g:6B4AAOSwQJhUkbnm&vxp=mtr

 

A lot of people have not had good luck with some of the aftermarket diaphragms out there. Do a search of, say, "diaphragms" in the 1st gen tech talk and be prepared to d a lot of reading!!

 

Unfortunately you are going to find it costs a LOT of bucks to completely rebuild the carbs with new parts, but it is well worth it!! Once PROPERLY rebuilt they should give you many years of trouble free service!

 

These bikes run like a raped ape when they are running right! Top speed is around 130 mph, they WILL pull a wheelie, and top speed in 3rd gear is 93 mph, as fast as the top speed of a Harley period...

[yamagrl]

Im going to chreck into the video mentioned.... I looked around for diaphragms and have not seen any for less than $30 a piece! But they definitely need replaced. Nobody has commented in the jets I replaced and how different they are from the ones that came out? So I'm guessing they are ok?? Would the diaphragms cause the problem I'm having?

 

 

$99.99 for 4 Diaphrams http://www.siriusconinc.com/pro-detail.php?pid=&product_id=1794

[gaj1917]

Re diaphragms - I bought four from JB Industries (http://jbmindustries.com/Yamaha650.html) at a cost of $20 each. These appear to be very sturdy, they work just fine, but I only have 4,000 km on them, so can't say much about their longevity.

[blitz]

I looked at these... how was the install??

[MiCarl]

Back to your base problem:

 

It is unlikely to be the diaphragms unless you buggered them up somehow when you worked with them. My 89 ran fine with holey diaphragms.

 

The new main jets are unlikely to be the problem. They really shouldn't be in play until the engine has spun up and you are moving some air through the carburetors. I cannot tell from the picture if they are Mikuni jets. I have seen problems with aftermarket jets so you need to have this in mind if you have high speed trouble later.

 

The situation you describe is consistent with the mixture going lean off idle. There are a number of things that can cause this:

 

1) Dirty passages or jets in the low speed circuit. The pilot (idle) jet and circuit should have a somewhat rich mixture. At idle that mixture is primarily supplied past the idle mixture screw. As you open the throttle there are extra orifices under the throttle plate that throw more of that mixture into the air stream. You can somewhat compensate for some blockage at idle by opening the mixture screws but as the throttle opens things have to all be right.

 

2) Air leaks. The obvious places are the carb holders (the rubber pieces that connect the carburetors to the cylinder heads) which can be cracked, misaligned or loose; leaking or missing caps on the vacuum ports and leaking vacuum lines. It's also possible, but less likely I think, to have air leaks internal to the carburetor. On your carburetor you have a jet block that carries the jets and attaches to the carburetor body. I can see where problems with that gasket might let excess air in. You can check for external leaks by spraying a modest amount of starting fluid on suspected areas and listening for the idle to pick up. Don't go crazy with the spray or you could get an unpleasant fire ball.

 

3) Grossly out of synchronization with a combination of other factors. You should get some sync gauges. I use THIS EMGO SYNCHRONIZER. Be advised that the vacuum lines that came with mine were crap and needed to be replaced. 12' of vacuum hose from the auto parts store won't set you back much. There are other gauges out there but for the money I don't think this one can be beat. A well running engine should have even vacuum on all cylinders of about 10". UNDER NO CIRCUMSTANCES PURCHASE A MOTION PRO SYNC PRO - it is very precise but unless your sync is very close you will ruin the gauge. Plus, it doesn't have absolute readings so it gives no indication as to whether the engine is running well.

 

 

I do this for a living and sometimes it takes several tries to get them right. Even when you get them right some crap may come from the fuel line and just mess them up again. Be patient and don't take any short cuts. You'll eventually work it out.

 

Having laid all that out here is what I think. 90% chance the problem is the idle circuits aren't truly clean or you put them together wrong. Do it again.

[BlueSky]

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1987/XVZ13DT/CARBURETOR/parts.html

 

Looks like partzilla may have the jets you need.

[blitz]

Back to your base problem:

 

It is unlikely to be the diaphragms unless you buggered them up somehow when you worked with them. My 89 ran fine with holey diaphragms.

 

The new main jets are unlikely to be the problem. They really shouldn't be in play until the engine has spun up and you are moving some air through the carburetors. I cannot tell from the picture if they are Mikuni jets. I have seen problems with aftermarket jets so you need to have this in mind if you have high speed trouble later.

 

The situation you describe is consistent with the mixture going lean off idle. There are a number of things that can cause this:

 

1) Dirty passages or jets in the low speed circuit. The pilot (idle) jet and circuit should have a somewhat rich mixture. At idle that mixture is primarily supplied past the idle mixture screw. As you open the throttle there are extra orifices under the throttle plate that throw more of that mixture into the air stream. You can somewhat compensate for some blockage at idle by opening the mixture screws but as the throttle opens things have to all be right.

 

2) Air leaks. The obvious places are the carb holders (the rubber pieces that connect the carburetors to the cylinder heads) which can be cracked, misaligned or loose; leaking or missing caps on the vacuum ports and leaking vacuum lines. It's also possible, but less likely I think, to have air leaks internal to the carburetor. On your carburetor you have a jet block that carries the jets and attaches to the carburetor body. I can see where problems with that gasket might let excess air in. You can check for external leaks by spraying a modest amount of starting fluid on suspected areas and listening for the idle to pick up. Don't go crazy with the spray or you could get an unpleasant fire ball.

 

3) Grossly out of synchronization with a combination of other factors. You should get some sync gauges. I use THIS EMGO SYNCHRONIZER. Be advised that the vacuum lines that came with mine were crap and needed to be replaced. 12' of vacuum hose from the auto parts store won't set you back much. There are other gauges out there but for the money I don't think this one can be beat. A well running engine should have even vacuum on all cylinders of about 10". UNDER NO CIRCUMSTANCES PURCHASE A MOTION PRO SYNC PRO - it is very precise but unless your sync is very close you will ruin the gauge. Plus, it doesn't have absolute readings so it gives no indication as to whether the engine is running well.

 

 

I do this for a living and sometimes it takes several tries to get them right. Even when you get them right some crap may come from the fuel line and just mess them up again. Be patient and don't take any short cuts. You'll eventually work it out.

 

Having laid all that out here is what I think. 90% chance the problem is the idle circuits aren't truly clean or you put them together wrong. Do it again.

 

Thank you so much for that detailed response I found it very informative and hopefully it will be the cure so I can get out there and enjoy it....

[snyper316]

And I have a motion pro in my garage which I have used the lines from it to fix other projects lol I bought one use for 80bux could have just paid someone to sync the carbs for that cause only got one use and the first one had to go back cause it had faulty O rings

 

Sent from my Z812 using Tapatalk

[snyper316]

By the way thanks for the detailed info

 

Sent from my Z812 using Tapatalk

[snyper316]

@blitz I could have picked one of those up the other day for 40 bux but do you have to calibrate those?

 

Sent from my Z812 using Tapatalk

[gaj1917]

I looked at these... how was the install??

Installed easily, just be real careful when using side cutters to cut existing hard plastic retaining rings. You risk breaking the plastic slide if you aren't.