nubie with help neeed

[spicy]

HI RZ forum
just acquired '85 rz350
has different cylinders "2GU" and different carbs mikuni VM34mm round slides //removal of the ypvs system
clean oil, clean coolant

got the carbs cleaned out with compressed air
removed the intake side and cleaned the reed cage and reassembled

Starts up sounds strong but it idles at 7-8000 rpm will not go down
Carb slides are at bottom , cable for throttle lots of slack..

Id be grateful for any help

pics::
https://www.amazon.com/clouddrive/share ... KoFmIUAOCm" onclick="window.open(this.href);return false;

[JonW]

you have a banshee top end I reckon, but it could well be aftermarket, but looking at it in the pics i would say not. These cylinders have no PVs and are lower power than the ypvs units by a significant amount if they are std banshee.

but VM34s are huge on a std shee cyl, so maybe these are not what they seem. whats the bore? 68mm? if so these are aftermarket.

high idle could be may things, have you checked for an airleak?

[spicy]

Unsure of the inside of the engine ... Previous owner says the guy he bought it from says no bore upsize
I checked for air leaks .. The carbs are sorta jimmied on at the moment .. but how much of a leak would cuase super high idle situation

[whyzee79]

not much

[mike YPVS]

Make sure the carb slides are actually hitting to bottom of the carb, I had some carbs that gave me no end of grief because the cable was not allowing them to go all the way down. Although they sounded like they were, it was actually the cable running out of travel that was making the noise.

[JonW]

... The carbs are sorta jimmied on at the moment ..

I reckon thats yer culprit....

if no bore upsize then youre running a std banshee top end.... 34-36bhp from memory. A ypvs will make 60ish.

[spicy]

Ill make sure to seal them off and give it another go

[two-stroke-brit]

i think a guy on here had the slides in backwards and ended up with the same problem.
also i have athena barrels with 2GU on them,
and they have no oversize available becuase they are nicosil linned barrels.
but are 392 cc(around 50 bhp) and you might have the same (68 mm dia pistons )

good luck mark

[two-stroke-brit]

ALSO i would really appreciate a picture or two of how your pipes fit to the cylinders as i am going to modify a set to fit if poss.
cheers mark

[spicy]

there was a hole drilled into one of the carbs on the intake side and that must have been the issue . started up with no high idle for about a minute.. stopped by itself and was not able to restart.. maybe flooded... slides were in correctly.. what do you think for the pilot air screw adjust it was on 1 1/2 turns open from fully closed

[two-stroke-brit]

1 1/2 turns out is std but it depends on what pilot jets are fitted.
mark

[MK]

there was a hole drilled into one of the carbs on the intake side and that must have been the issue . started up with no high idle for about a minute.. stopped by itself and was not able to restart.. maybe flooded...

My guess: The vacuum hose between one intake and fuel petcock is missing.
So the bike is running until the float bowl is empty coz the petcock does not deliver fresh fuel.
Try on "PRI" for a quick debug and if that works, connect the described elements ...

[spicy]

The fuel line has a single with a brass filter to a tee that goes to the carbs .. I see another black line connected to the rear of the petcock but is that for drain or for vacuum ..there is only one second hole on there are a couple pins on the bottom side of the carbs with nothing attached

[Questo vecchio rz]

Your target are at this point generally is too big to accurately pinpoint , Id do a complete and check of every component and system. Some basic thought & questions I'll throw into the hat are,
*.) You say YPVS " removed" so I am assuming you have a stock cylinder head with YPVS engraved into it ?
Also a spacer plate and 34mm carbs. Along w the suspension swap it sounds like someone was building a fun lil track toy. More than likley a 4mm stroker crank.
*.) There could be a few issues regarding spacer plate and YPVS valves, port timing etc.., but it is what it is at this point, to start some things to check. The YPVS valve should be checked to see if it's wired "fixed" fully open.
*.) The carbs always need to be checked, even sitting for two weeks they can clog up. (If it ran before, it should run now), so don't go off and start rejetting before you know, clean everything & clean it again , make sure all carb parts are with the correct carb,fuel filters, your floats are set correctly etc..
*.) Check your intake reed condition ,make sure it's airtight
*.) Check your ignition/ timing etc..
*.) Obviouslly a leak down and pinpoint any airleaks. anywhere.
The 34mm carbs and open YPVS valves are great for a track bike on large tracks with alot wide open throttle available. But on a (street bike) , it will likley be a poor as you will have giant vacant hole in your low/mid range accelerating from a dead start is sure to be a frustrsting affair. Some may argue this, I'd say simply as they have no alternative. Its a fact, the YPVS allows the bike to have both benefits of maximum low end and topend performance. Without it it's a comprimize you can't have both. If this is destined to be a road bike. I'd look into at least going to stock sized 26mm or 30mm carbs maximum, the lack of YPVS is still a problem in that area, but the smaller should provide better low end usability and still deliver as much topend speed you will need for the street.
*.) Also, can you find out what the build is from the previous owner? Find out if it's stock. A 4mm a 7mm etc.. what brand of carburetors etc..
Your bike has a extensive amount of modifications done to it, depending on how correctly & recent the work was done, you might not have to spend much $ at all. Cosmetics may just be your biggest investment, you have a very nice base project to start with. But I would caution that is ONLY if the previous owner did everything correctly. Hopefully there's a good end in sight.

[JonW]

no ypvs, he has banshee cyls as I said, there are pics linked...