Vmax Cams & Venture Carbs

[Reaney in NH]

I'm gathering parts to do some upgrades on my new to me 96 Tour Classic.

 

I scored a nice set of Venture Carbs, Carb boots & air boxes on ebay... a local machinist buddy will make the plates and shave the boots.

My question about the carb... Main jet parts numbers?? 125 mains is where I will start with 17.5 Pilot. Without taking my carbs apart... I'm not positive on the correct ones. Can you help? are they Large Round mains? Small round? Hex?

 

Vmax Cam & Valve springs swap? Can I do this with the heads on? never done a bike before.. but Ive many valve springs on cars by injecting air into the cyl to hold valve.. can I do this on the bike?

 

I am buying the tool for the Valve shims.... anything else I need?

 

I am installing a 4 into 2 exhaust... I purchased in ebay. I beleive the head pipes are stock Venture... muffs included are straights... I dont think I will use them. Planning Road King muffs with centers punched out.

Also planning DynaTek DK37-4 .....

 

Not sure on Air intake... but prolly run a stock airbox opened as much as I can. I'm not a fan of K & N... I really think they let to much dust on the engine.

 

Any thoughts... anything I'm missing?

Thank you

Reaney

[DarrinGT]

About the same things that I have been dong over the winter on my bike, minus the V-Max Cams.

 

Read through this thread, lots of info and pics.

 

http://www.venturerider.org/forum/showthread.php?t=83141&highlight=makeover

 

When I have more time I will get back to you and help answer some questions .

 

Good Luck!

[bongobobny]

I'm sure Dingy will chime in soon, he's the local VMax expert!

[Dano]

If'n you wanna go a bit more.....

 

I've got a VMax carb mount that'll tie your front and back cylinders together, gives 'er more gas across the spectrum to help that front wheel come up.

 

$50 and it's yours.....

[dingy]

If'n you wanna go a bit more.....

 

I've got a VMax carb mount that'll tie your front and back cylinders together, gives 'er more gas across the spectrum to help that front wheel come up.

 

$50 and it's yours.....

 

Problem with mounting the VMax VBoost on an RSV/RSTD is that it raises the card rack 1 1/4" higher. This causes the carbs to interfere with the fuel tank by a lot. There is not a chance the VMax air box will fit, there is no way it would clear the tank in its unmodified condition, even if the VBoost intakes are not used.

 

Also the VBoost unit has different spacing front to rear on the carbs than a 2nd gen.

 

The cams & valve springs are a direct replacement for the RSV and RSTD's.

 

Gary

[Venturous Randy]

Not sure on Air intake... but prolly run a stock airbox opened as much as I can.

Any thoughts... anything I'm missing?

Thank you

Reaney

 

These bikes can be real sensitive on mods to the airbox. Opening up the airbox may cause the carb slides to not have enough vacuum and not open properly.

RandyA

[Reaney in NH]

Not sure on Air intake... but prolly run a stock airbox opened as much as I can.

Any thoughts... anything I'm missing?

Thank you

Reaney

 

These bikes can be real sensitive on mods to the airbox. Opening up the airbox may cause the carb slides to not have enough vacuum and not open properly.

RandyA

 

Maybe I'm missing something... But How can opening the air box up effect how the slides operate?

I can certainly see how it can effect A/F mixture.... requiring jetting changes and tuning. But the slides operate from an internal vac source... So I dont see how airbox can effect it.

If this is the case... can you explain?

[Venturous Randy]

These bikes can be real sensitive on mods to the airbox. Opening up the airbox may cause the carb slides to not have enough vacuum and not open properly.

RandyA

 

Maybe I'm missing something... But How can opening the air box up effect how the slides operate?

I can certainly see how it can effect A/F mixture.... requiring jetting changes and tuning. But the slides operate from an internal vac source... So I dont see how airbox can effect it.

If this is the case... can you explain?

 

I may be wrong, but it is my thinking that with the slides being opened by vacuum, opening up the air box too much may impact how efficiently the slides move. I know that on 1st gens, when you mess with the air box, it usually runs worse. Take the air box off and many barely run and will backfire everywhere.

RandyA

[Reaney in NH]

Maybe I'm missing something... But How can opening the air box up effect how the slides operate?

I can certainly see how it can effect A/F mixture.... requiring jetting changes and tuning. But the slides operate from an internal vac source... So I dont see how airbox can effect it.

If this is the case... can you explain?

 

I may be wrong, but it is my thinking that with the slides being opened by vacuum, opening up the air box too much may impact how efficiently the slides move. I know that on 1st gens, when you mess with the air box, it usually runs worse. Take the air box off and many barely run and will backfire everywhere.

RandyA

 

They run worse because they are lean and get to much air. it has nothing to do with the vacuum that opens the slides. This can be compensated by adding the proper jets and correct tunning.

[Reaney in NH]

Can I do cams and valve springs with the heads on the bike?

 

Does anybody know if I can?

[greg_in_london]

Well you can take the cams out - I can't think of anything that would stop you and that's 'normal' on bikes, but whether you can do valve springs as well depends on your compression tool that you said holds the valve pneumatically. It would certainly be fiddly, so it would be up to you if the work you saved by dismantling less and not having to replace gaskets was balanced by making the job a PITA. Your fingers may be skinnier than mine though..

[Reaney in NH]

OK... I figured out the Jets.... you can use the Small round or the large round jets..

the Pilot jet are for the VM 28/486 #17.5

 

Yamaha part # N102.221-125 ... the last 3 numbers are the jet size

Dennis kirk is the large round... 17-418 I think.

 

i hope this helps someone in the future.

[Reaney in NH]

For the cam swap & Valve springs....

 

If I did choose to remove the heads for the install... are the heads removable with the engine in the frame... or do I need to pull the engine too?

 

If I remove the heads... will the standard valve spring compressor like i would use on a car work on these heads?

 

I'm an old school car mechanic... have not done alot of in depth engine work on bikes. but I am looking forward to this project.

 

I want to log some miles in between each upgrade so I can feel the changes as they happen.

I'm really impressed with the results others have gotten... a 50% increase in HP is pretty remarkable for the minimal investment in parts... and all stock Yamaha parts.

[DarrinGT]

For the cam swap & Valve springs....

 

If I did choose to remove the heads for the install... are the heads removable with the engine in the frame... or do I need to pull the engine too?

 

If I remove the heads... will the standard valve spring compressor like i would use on a car work on these heads?

 

I'm an old school car mechanic... have not done alot of in depth engine work on bikes. but I am looking forward to this project.

 

I want to log some miles in between each upgrade so I can feel the changes as they happen.

I'm really impressed with the results others have gotten... a 50% increase in HP is pretty remarkable for the minimal investment in parts... and all stock Yamaha parts.

 

 

From another member here from this thread: http://venturerider.org/forum/showthread.php?t=82640

 

I pulled heads and cyclinders in frame to regasket when they blew no easy but can be done, the frame on the 96 had a section that bolted in at the top, with that removed rear head and carb could be lifted right out leaving room to remove front head and slide it back and out

 

 

So it looks like it can be done,..

[StarFan]

From another member here from this thread: http://venturerider.org/forum/showthread.php?t=82640

 

I pulled heads and cyclinders in frame to regasket when they blew no easy but can be done, the frame on the 96 had a section that bolted in at the top, with that removed rear head and carb could be lifted right out leaving room to remove front head and slide it back and out

 

 

So it looks like it can be done,..

 

My 1998 Royal Star Tour Classic was done with the engine in. The section in the upper frame beside the top of the carburator is bolted and can be removed, thus giving space for the heads and carbs to be removed. No need to remove the engine from the frame.

After trying my bike for the first time after having the 32mm Venture carbs and the V-Max cams and stiffer springs installed I have to say that I was more than impressed. It is a whole different bike and will leave a 80 foot black mark on the road if you are not careful. That bike is really fast to say the least.

Lets not talk about gasmileage though

[a1bummer]

If'n you wanna go a bit more.....

 

I've got a VMax carb mount that'll tie your front and back cylinders together, gives 'er more gas across the spectrum to help that front wheel come up.

 

$50 and it's yours.....

 

If you still have those and nobody else has dibs, I'd be interested in taking them off your hands. I'm getting ready to drop an 86 1300cc into my 84. I've been eyeballing those for some time. I would love to up my game a bit more. Kind of curious how they might effect the mileage though.

 

Thanks,

Bill

[Reaney in NH]

Good Morning everyody,

I thought I would give a little update and perhaps get a little advice.

 

I removed the heads... made a Valve compressor tool and swapped in the Vmax springs and the Vmax cams. I thought it all went pretty well.

As I was putting it back together I did rin into a little trouble figuring out cam timing positions. The Manuals instructions were very confusing and lacked some key info. I found this... http://vmaxchat.yuku.com/topic/11324/How-to-replace-time-in-your-Camshafts which gave some very clear instructions. Using that info it went right together.

 

I cleaned and rejetted the RSV carbs... reset float levels per Gooses instructions. Installed and fired it up.

 

I balanced carbs... they were off quite a bit and it seamed to run ok. But it would pop out left side... Popping seemed like it went away after more idle screw adjustment but the throttle seemed a but flat... not the crip snap one would expect. I test drove it. I was disappointed and it popped like crazy.

 

Back on the lift.... I discovered #2 cyl is not pulling at all. Its causing the popping out the exhaust. My guess at this point is I did something wrong... like bent a valve.. got it to tight or something causing it to leak. I do not have a compression or a leak down tester to fit the small plug... but its been ordered.. will be here by Sat.

The Cyl pulls good vacuum ... its strong and stable. On a car, a leaking valve will cause a vac gauge to flutter like crazy... I was able to balance the carbs with the Carbtune vac gauge.

 

In case anybody is wondering... Coil to #2 is firing, I checked. I switched #1 and 2 plugs... miss stayed in #2 cyl. I tried enriching the fuel by adding carb cleaner thru vac house... with no change. Other 3 cyls all Balance test strong... #2 is doing nothing.

Bike was brand new to me.. I rode it less then 1

20 miles and was not impressed with its power... its possible it had and issue before my work... I cant say for sure either way.

Your thoughts?

[speakerfritz]

before committing to a particular cam swap, double check what the compression ration should be to support the cam. cams that move power to the mid band typically need higher compression pistons.

 

vmax has a compression ratio of 10.5:1, 2nd gen royal star has a compression ratio of 10.0:1. dont know what a first gen royal star has.

[Reaney in NH]

This cam swap has been done many times by many people on this forum with no issues and a huge improvement in performance.

 

Thank you for your input... but the CR on this bike has nothing to do with my current problem.

 

I either bent a valve... or possible problem with a shim or shim cup. I'll know more when I get the leak down tester.

[dingy]

before committing to a particular cam swap, double check what the compression ration should be to support the cam. cams that move power to the mid band typically need higher compression pistons.

 

vmax has a compression ratio of 10.5:1, 2nd gen royal star has a compression ratio of 10.0:1. dont know what a first gen royal star has.

 

1st gens also have 10.5:1 stock comp ratio.

I am running 12.2:1 (about) on a 1300 block with VMax heads & cams, & block modifications. Mid range does have most power feel.

Compression test should confirm or eliminate valve train leakage.

Gary

[Reaney in NH]

yes it will.... as soon as I get the adapter I will post results