Jump to content

RD/RZ350 YPVS engine in my banshee


Recommended Posts

Rare, thanks for you interest/input. Have tried to answer some of your points below :-

 

1. I do run with tickover. The thing always starts easy (first time with little or no choke) and will tickover for ever.

2. I must say that the right piston has shown signs of overheating and probably not far behind left piston from destruction.

3. Don't know anything about leakdown tests ???

4. Still confused with plug range ? I thought the lower the number the colder it runs (i.e. less overheating) I have had advice from Stan Stephens previously and I

Link to comment
Share on other sites

  • Replies 38
  • Created
  • Last Reply

Top Posters In This Topic

To do a leakdown test, you need to remove the pipes, and plug the exhaust ports. Then remove the carbs and plug one side and put in an adaptor with a pressure guage and pump on the other side. Now pump up the pressure to about 5 pounds. Now watch the pressure guage, it should hold 5 pounds of pressure for about 5 minutes. If it drops, you have a leak. To find the leak, use a mixture of dishsoap and water, and run this around the base gaskets and intake boots and gaskets. If you find bubbles, then you have found your leak. You can make one of these tester with parts from your local hardware store, or I think motion pro makes one as well.

Link to comment
Share on other sites

1/ 'Good to Rich' on the Pilot with tickover, that's fine.

2/ I wonder if the gear oil up against the right side crank case is enough to make the difference to let the left side burn up first. <_< . BTW - What was the reason for being richer on the left with the extra full throttle jets?

3/Leakdown test: pluging up the exhaust outlets, intakes and plug holes, and putting 6 or 7 psi into the cylinders and seeing if it holds the pressure for 10 mins with very little or no loss.

EDIT: cbn70 explained it better.

4/ Plugs: The lower the number, the lower it's ideal working temperature. ... If you put a 8 in where a 9 is reccommended, it's ability to remove heat from combustion is reduced.

 

Stan did the porting and head work on my motor. ... I can't see him saying go to a lower temperature plug, but if he said "try a colder plug" he means a 10. Might be better giving him a phone to check.

 

5/ Yeah, more compression = more heat and an increase in octane requirement and possibly a 'colder' plug if neccessary.

7/ You can only read the mains where the porcelain meets the shell, deep inside the plug. ... 1mm soot ring. (Use new plugs - warm up the motor on the old plugs).

Yeah, blueing is heat.

8/ So stock clip position on that needle is 2nd clip from top? With 5 grooves? I run on the 5th, but that's not relevant here. What did you do, go back to 2nd clip for the race?

9/ You're more likely to overheat from being too lean than being too rich. ... Jet up 'till it sputters/ bogs, and then come down a size.

10/ Ok, RZ gears

12/ That's good advise on the Optimax. ... It's 98 (R.O.N.), but it's really only 93 Octane (R+M/2).

13/ I use silkolene also. (Pro2 @ 33:1).

 

Have you done any (cold) compression checks with the fresh rebuilds?

 

- If you've only been using regular unleaded 95 (91) and you have that head reworked, have you not heard any knocking/ pinking?

- Moving to the BR10s is going to help if they are'nt going to foul up.

- Engine Ice or Water Wetter would be a good idea if you don't want to go the way of a cool head.

- Keep in mind that with the 28mm bore of the carbs will produce less velocity and therefore richer adjustments are required to compensate.

- If you do phone Stan, ask him about your premix to see if he would reccommend richening the oil content. (Remember that doing this will lean out your fuel:air mix).

 

Throw some 28PWKs on there for an easier and less wallet emptying life! :D

 

Rare.

Link to comment
Share on other sites

Rare, cheers, got loads of info to chew on now. Wil get back to you with answers to above and have more ideas/variables to throw in the pot !

It'll be some time before I can actually try new settings carb etc coz frame at powder coaters, then lots of other jobs to do as I put it together. The engine itself is ready to go.

Hopefully shee will be up and running 2nd week in August, then need to get it run in and running cock on ready for 8hr endurance race at end of August. Think I'll get a spare engine ready to swap in the pits

You coming diown to sunny Devon for that !!!?? (Great 8 Endurance).

Link to comment
Share on other sites

Hopefully shee will be up and running 2nd week in August, then need to get it run in and running cock on ready for 8hr endurance race at end of August. Think I'll get a spare engine ready to swap in the pits

You coming diown to sunny Devon for that !!!?? (Great 8 Endurance).

396178[/snapback]

8 hour endurance. :o . ... I can hardly finish the 3rd 20 minute MX race. :D . Where's it held? I'm often down in Devon, my Mother lives there now.

 

Here's where I got my Engine Ice. It's not cheap ... About

Link to comment
Share on other sites

:clap: Cheers again Rare for the info. Got more 'essays' to write yet on info so maybe I'll PM you direct.

 

:headbang: The 8 hour endurance race is a a one off event organised by QRA (Tony Nash) and Ride-It (a fairly new club set up here in the south west). Ride-It have previously held some really good events and had some British Champ rounds with Winrow and the likes racing and I'm sure all the top boys will be at the 8Hr.

 

:P I must say my current fitness level would prevent me from completing a 3hr enduro let alone 8hrs, but you can do a 2 man team event (with either 1 bike or 2)taking it in turns whenever you like. Also although it is a competition, the emphasis is on FUN. High price entry fee (

Link to comment
Share on other sites

There may even be a Hill Climb (twisty tarmac drive) on the Saturday night. This is a famous venue in the South West for hill climb events for all types of vehicle but I think is the first time for quads !!!

396381[/snapback]

If the hill climb is Wiscombe, then that's only about ONE mile from my Mother's house. ... That would be awesome on a quad! ... Bridge Corner, Bunnie's Leap, The Esses, Sawbench hairpin, then a 250ft straight to the last corner and finish line. (900 Metres in total). :bolt:

 

Yeah, pm's fine.

 

Rare.

Link to comment
Share on other sites

Yep it is the Wiscombe venue. I only live 20 miles away in Exeter so handy for me.

 

Anyway onto piston analysis. Have been on the website: -

http://www.mztech.fsnet.co.uk/workshop/wrk_piston.html

 

Left hand piston when failed usually looks like picture 'BURNT-OUT BLOW-HOLE'

although it has never actually holed, but almost and the picture otherwise is identical to what I have found before.

 

As for the right hand piston it usuall looks a little overheated but last time it started to show evidence of a 'FOUR-CORNER SEIZURE'

 

This has helped me clarify and identify possible causes that have already been mentioned by others and suspected by me.

Link to comment
Share on other sites

You shouldent' have any problem with cooling on the RZ, I think most of the guy's would agree that the water jackets may be even bigger than the COOL HEAD.If your head has been shaved and you havent' been ported & polished you really should be running a good race gas(110).The bigger your port & polish the less octane required. Sounds strange buy it's true had it happen to me . Please just buy a set of stock banshee 26mm carbs on Ebay. Run them fat like 34-- 300. Then you can eliminate any questions on carbs, i've heard more guys have problems trying to just get the rd/rz carbs to work right , save yourself headaches and time go with somthing that is easy to figure out.

Link to comment
Share on other sites

  • 8 months later...

spark plug heat range goes up as the number goes down ie: a 7 is hotter than a 8.

 

A.W. the reason some swap the rz or rd motor in is for the use of powervalves. they give ya more low end cause the exhaust port is controlled by the PV. lol the ultimate 2 stroke swap would be the gamma 500 WooooooooT :bolt:

Edited by Wicked98Shee
Link to comment
Share on other sites

I've tried searching for threads on here about Banshee owners running the RD/RZ350 YPVS engine, but the search doesn't come up with much.

 

I've had my shee for 18 months and it already had the YPVS engine fitted. Now I have much experience with this engine and know it inside out including the electronics etc, BUT i have always had a problem setting up the engine. It always starts well, runs well, pulls well, but the engine just doesn't last long enough, it will usually blow within 3 hours !!! I have tried hundereds of variations of jetting, but to no avail and lots of expensive rebuild. It usually overheats when really cained.

 

Details:-

Engine - RD350 YPVS (F2) 1WT approx 1990

Carbs - Mikuni 28mm, Pilot jet 27.5 (stock), needle clip 2nd groove down (stock)

main jet 260 (180 stock) Power jets 55 stock left hand 50 stock right hand carb

 

Exhaust - FMF Fatty front pipes, Power Core 2 silencers

 

Air box - standard with snorkel removed and hole cut to rear of lid

Filter - standard

 

Ignition timing - standard non adjustable

 

Reeds - FMF  fibre

 

Plugs - was using BR9EG but going to try BR8EG

 

Anyone else got any experience ?

395625[/snapback]

 

 

 

 

How is your head/squish clearance set-up. RZ heads are border-line time bombs unless modified for off-road balls to the wall riding habits....Jim

Link to comment
Share on other sites

Really?

496033[/snapback]

 

YES broke, but your covered on your motor, and Dan took care of it on your other RZ motor too. Squish velocity's on those heads are very high to begin with, most likely an attempt to build decent bottom end on the original Yamaha design, although there were better ways to do this other than increasing squish velocity. Start milling the head, adding high volume expansion chambers, and running slightly leanish jetting and youve got a situation that is less than very reliable...JIm

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...