bigredspeed,
Good luck with the VZ-R. I run it in a 1/8th Spec class here in TX. On my last time out I ran into an issue. Upon reviewing the engine after the blow up :flaming:, I noticed that the High Speed needle had threaded loose. This caused a high rev and a lean mixture - low amount of fuel and or lube in the engine - which resulted in a blown rod. If that was not bad enough, it happened on the first warm up lap in the main. Yikes!!! Oh well, bought a new VZ-R and sleeve/piston/rod for the rebuild on the old one. Will be breaking in two VZ-R's this weekend, then back to racing next weekend. Crap, that is going to take a bit of fuel. Don't forget to double check that the high speed needle is tight.
Good Luck,
Roger

Hi,

I have some problems with my carburetor too. It leaks somewhere but I can not find it. I install a nova carb instead of the original one. I will keep you informed about the leakage and the performance.

what pipe have you guys been running with the VZR? I used to run it with a Nova 2006, will it run better with a 2052?

Lastly any of you have experience between the 2006 vs 2052 tuned pipe or the rx21 kangaroo vs the pr321 vs vzrII.

Thanks in advance

I think you guys should run the speed connecting rod. It's stronger and knife edged. It should help your top end and break less

Hey, thanks for your info. ....... I also have two OS speed conrods for VZ-R conrod replacement.

Btw, have you really use it for VZ-R ? ( sorry to ask, because OS speed conrod meant to be use for VZ-B , am I right ? ).

ASW,

Yes, use the speed rod. It has an oil hole in it. The Speed crankshaft does not have an oil hole in the crankpin like the stock crank does. I run the speed crank and rod in my VZ-Rs with no problem.

Deepfreez,

Check the slide boot. They get loose at the big end and let air leak in.

Good luck!
Socko

Ok, thanks for your confirmation, jonny. :)

Just come back from Jakarta Futaba Cup 2008. Today was qualifying of 3 rounds. Tommorow is the last qualifying round before I go to C final. I use OS VZ-R ver. II in this prestigious race. There are 120 participants for 1/10 and 1/8 classes. Some participants comes from Malaysia, Thailand, and Singapore.

Long story short...... I keep leaning it until I reached 120C after the heat *** . Bottom end acceleration is indifference compare to high end Novarossi engines. However, top end power ( acceleration toward top speed and maintain top speed ) is rather scary because Novarossi engine drivers are tail gating me very very close. I'm sure they back off a bit to prevent crashing at the end of back straight. I lost about 2 or 3 feet if they are accelerating in front of me at the long back straight.


*** This is what I heard from other VZ-R owner(s) : OS VZ-R engines have durability problem with main bearing operating at very high temperatures. The plastic cage that keep the ball bearing together might deform badly due to heat !! :eek:

To say the least, I am happy to say this engine is really worth the money.

Hi Guys, Fianly ran my VZR today with VZB speed Crank:D and yes it was moving good :deathstar, clutch set up could off been set better:(, but i had good time running it, i also used Tornado fuel today for the first time and i highly rate it. the Crankshaft really made a diffrence. What a awsome engine for the price:nod:

WAITT !! I think I want take my compliments about VZ-R engines.

I just come back from main final today, and my final wasn't good at all. I got four times flame out during the final...... My mechanic put a new glow plug, and yet the engine still flame out again at long straight. I don't know why the engine suddenly can lean out by itself :weird::weird: and it reached 140C :eek::eek: The problem cease when my mechanic richen the engine by quarter of turn ( 15 minutes ), ...... oh well, the damage has done.

It's really confusing what to check / what to blame now ....... I did my warm up laps before start for 5 to 6 minutes, and my mechanic get temperature reading of 109C, and he did double check the temperature again before start, it still show 109C.

My mechanic suspect this engine cannot be use for more than 10 minutes..... after 10 minutes the engine start lean by itself ?? :weird:

What went wrong ??

ASW,

Engines don't lean out on their own during a run. Check over the car and make sure everything is still good (pressure line, fuel line, clutch, tank seal, pipe and header seals, carb boot, air filter, drive line.)

What plug are you using?

Let me check the fuel line tommorow...... maybe there is a leak there....

I was using P8 glow plug.

Okey, I already open the engine, ..... I think I know what went wrong.

I think my fuel tank got some dirt particles in the first place, and some dirt particles enter into carburator and stuck there, causing it to lean. As temperature rose to 140C, the glow plug become dead. Perhaps some glow plug filament fell into the combustion chamber and scratch the piston sleeve badly. And I get three more flame out again due to compression lost and dirty carburator.

Oh well, next time I use inline filter again.

ASW,

i have had that problem in the past, same thing happened to me also, kept scratching my head over it and my mechanic also, i checked everything that was meantioned by Jonny, i then looked at my clutch tension spring, it had wound it self tight causing the motor to really reach high RPM and due to lack of presure through the pressure chamber not enough fuel was going through to keep up with the engines rpm output. due to the higher revs then there was not enough fuel going through the motor causing it to over heat and flame out. when i loosened the clutch spring the motor ran perfect again. this would only happen to the motor down the main straight. i hope this has made some sence to you, well im assuming that was the problem at the time. it seemed to have had fixed it when i loosened the clutch spring tension nut.

ASW,

Glad to hear you figured it out. Too bad it ruined the sleeve. At least parts for the VZ-R are less expensive than the high end engines. Check your bearings when you rebuild it as well to make sure none of the dirt or element particles got in them.