OS V-Spec Question
 

I got a used V-Spec from a local racer a few weeks ago. From the first tank, it would not idle right and could not get the tune right. Also, it ran way hot at 250-260 after a warm-ups and a 5 minute qualifier. I just took the motor apart and found that the rear bearing was rusted on the outer edge, as well as the crankshaft being quite rusted. Also, the rear bearing is not operating smoothly at all. Is what I found the cause of the tuning problems and the motor running hot? I spoke with OS and they agreed but I wanted to ask around before spending the money on new piston/sleeve and bearings. Also, what is the temperature that a V-Spec should be tuned at? It has the stock cooling head btw. Thanks for your input.

I would not hesitate to run my engine at those temps. My rule of thumb is if its blowing smoke, running well and temps below 300 then its good for me. I try to run between 230 and 260 but dont get caught up with temps as there are ALOT of factors that can very to cause temps to run higher. If your running 20% with high oil it will run hotter then with byrons gen 2 30% with 9%oil for instance. Also it depends upon the temp gun used. I have a cheapy but check mine every now and again with a exergen temp gun as they are WAY more accurate.

As far as the mechanical problems you described it sounds like the previous person didnt drain his tank or used old fuel that collected moisture as that is the only thing that would cause rusting. If you wanna rebuild it thats up to you but sounds to me like there is enough wrong where it wont be cost effective to do so. I personally would buy another motor and this time dont get a vspec is my advice. Just my opinion though.

Hope the above info helps.

v-spec is a great mill and should be taken care of! To hear that the crankshaft has rust on it is rough. If you are a club racer and handy, I would recomend cleaning up the crankshaft, inspecting the P/S and replacing the rear bearing. The rear is just over 20 bucks for a TKO ceramic and you CAN get rid of the rust on the crankshaft with a little TLC. Make sure you check your conrod for play and if there is any between the bottom and the crank pin, replace it, its only 30 bucks. No need to buy new if you can spend a few hrs and fix this one.

When you're checking the P/S make sure there are no scratches or gouges in the sleeve or piston and make sure there is a decent amount of pinch with the glow plug in. If there is no compression I would recommend the same as the above post, however if there is its worth saving!!!

Good luck, let us know how it goes

+1 get a TKO ceramic and polish up the crank my bearing went and i replaced the conrod and bearing it now flies and is still going strong, as for temps dont use them much and use deg C to be akward but have beed told by a very good guy to run mine at 100degC plus the ambient temp so if the temp is 13 degC run the motor at as near to 113 as poss if that makes sense it should convert across easily enough, just done it for you 100 = 212 degF hth

p.s. if you are getting another motor then theres nowt wrong with a v-spec

Piston and sleeve are toast. When I was running this weekend, the motor was running okay and then all of a sudden I lost compression and power. It made the temp gun temp HI when I pulled it off. I am debating getting a new one versus rebuilding this one. There is $150 difference that I am not sure I want to spend. I have already polished the rust off of the crankshaft and it is now shiny and slick as glass. I don't know as I have had nothing but bad luck with this motor. I think I want to do away with the bad karma and buy new, but the money is keeping me back from it.

On Amain you can get it for 274.99 with this discount code

$250 or more $25.00 JJDCPP825

It is also free shipping.

did you change the bearing as well or just polish the crank ?? if you left the bearing in rusty then that would explain it, you may be able to get the liner pinched if its in good condition still i.e. no scratches on it or the piston, if not prob best go new it sounds like that motor has ben ran some and then given away as its no use to the previous owner anymore, give us some more info on what you did to it before running this last time and we may be able to give more help back :cool:

Hard lesson learned I guess.
I've found racers very rarely sell good motors. It's usually the ones who are getting out of the hobby for good that you may get a decent motor off. Racers however keep the good and junk the bad. I've been through the same turmoil with V-specs. It was my fault that the con rod broke, but after spending heaps of dollars on that motor, it would of ended up being cheaper for me to just buy a new one in the end.

i dont think you did too bad buying the Vspec, as cheap as it is to rebuild, you should be fine.

buying it new is ideal, but you already have it, so just rip it till it loses compression and rebuild it after taht point. no point in spending money on it now...

I did not polish/clean the crankshaft until after the motor was toast and lost compression. That was when I took it apart and noticed the rust on the crankshaft and rear bearing. I paid nothing for the motor, it was a gift from a reputable local racer who I have helped out with their business. The motor had good pinch on it when I first got it. Just was very hard to tune the low end and came off at high temps. Was in the 70's here and came off at 270 at first and then at 250-260. There are several racers that run V-Specs that have the stock head and run them at 225-240. With the Trinity head they are running them at 200-210. I even had the local sponsored pro to look at it and tune on it. He had problems tuning it. Again, this was before it was taken apart and the bearings and crankshaft found to be rusted and the rear bearing sounding like sandpaper. I have only run Trinity 30% and use after run oil. Just sounds like the rear bearing was bad and everything just snowballed. I am probably going to just get a new one and use this one for parts. I think another club racer needs a crankcase so I might give it to him.