Cr-500 Help!!

[jski]

I went to install a V-Force reed valve in my 2000 CR-500 and it doesn't sit all of the way in there is about a 1/16" gap between the valve and the cylinder. Upon measuring the valve at it's widest point it measured 81.2mm while the opening in the cylinder measured 80.2mm. I spoke with Moto Tassinari this morning and they said they have never seen this problem before and that the reed opening on the cylinder must be smaller then normal thus causing the problem. They sugessted to file the side of the cylinder down to make the vavle fit or file the side of the cage down. What do you think about this and does anyone here know what that opening is supposed to measure?

Thanks,
Jim

 

[Faded]

Originally posted by jski
. They sugessted to file the side of the cylinder down to make the vavle fit ...What do you think about this...

Jim,

I said "Hell no!" I wouldn't file down the cylinder to make it fit! Some of those metal fillings could get into your bottom end causing a terrible rash...oh, wait, wrong bottom end. I mean those metal fillings could cause problems if the fall into your motor. If you just have to do it, then stuff a rag tightly in the intake so when your done you'll (hopefully :eek:) pull out all the fillings with the rag when you remove it. I'd be more apt to filling the reed cage before the cylinder, but these are both last resorts! First I'd take the cage back to where you bought it and see if you might have the wrong one. If you mail ordered it, take it somewhere locally where the sell them and ask to look at one. Once you start filling it will be impossible to return it. If V-Force has never had this problem then I would think they would be more than willing to trade you for a new one before you broke out the files.

My $0.02

 

[Superchief]

I would have to agree with Faded. If it's the right part for the right bike and Moto-Tassinari has never heard or had this problem before, then i would'nt file @#$%. once it's filed, there is no going back. I'd try the local shop thing first and then go from there. If it was up to me, i would'nt file anything on my bike to make something that's made for that bike to fit or work. I'm sure Moto- Tassinari would be willing to help you out in whatever way they can.

 

[jski]

Thanks for the replies.

I ordered it directly from Moto-Tassinari because the local shops were out of stock. I talked to them again today and they are willing to fix it if I ship it back to them but get this they will file it but thats about it. Not real happy about this because I already cut my boot down as suggested so no going back to the stock cage. The cylinder is off because I was doing the top end so I could clean it up but I still shouldn't have to just to fit the part.

Thanks Again,
Jim

 

[cujet]

well, if the cylinder is off... That is not a big deal to make a part fit. Especially if it is a few mm's. I would not want to remove material from the reed cage, as they are plastic and quite thin as it is. Use a carbide bit or other cutter to do the job right.

Chris

 

[Studboy]

If the cylinder was off spec, wouldn't the stock reed cage have fit problems also?

Just a thought.

 

[EricGorr]

They should change the name from V-Force to FITZALL. Ok this may be a shock to some of you guys but the design of a reed valve is actually quite complicated and requires either computer simulation of cubic dyno testing time. V-Force makes a few basic valve sizes and then its up to you to modify your cylinder and intake manifold to make it work. I can't tell you how many kids with 125s that have sent their seized cylinders to me for repair after they haphazardly modified their intake manifolds with a hacksaw. I always ask them "did you recently install a V-Force? ". Most Japanese intake manifolds incorporate a molded o-ring for sealing purposes in order to replace a gasket which is subject to failure by leakage. When a hacksaw is used to cut off the molded inserts like V-Force recommends in their instructions, its easy to slip and damage the o-ring. Then the manifold leaks and the engine seizes. Another problem is that most people don't match the manifold to the reed cage because they have a die grinder to properly match the parts. This can cause a loss of power from the gross mismatch.
The bottom line is that V-Force reed valves don't work on everthing and there is a lot of customization involved in making them working like they're intended.
My advice is if you don't have the skills or patience buy a RAD Valve instead.

 

[Superchief]

Originally posted by EricGorr
They should change the name from V-Force to FITZALL. Ok this may be a shock to some of you guys but the design of a reed valve is actually quite complicated and requires either computer simulation of cubic dyno testing time. V-Force makes a few basic valve sizes and then its up to you to modify your cylinder and intake manifold to make it work. I can't tell you how many kids with 125s that have sent their seized cylinders to me for repair after they haphazardly modified their intake manifolds with a hacksaw. I always ask them "did you recently install a V-Force? ". Most Japanese intake manifolds incorporate a molded o-ring for sealing purposes in order to replace a gasket which is subject to failure by leakage. When a hacksaw is used to cut off the molded inserts like V-Force recommends in their instructions, its easy to slip and damage the o-ring. Then the manifold leaks and the engine seizes. Another problem is that most people don't match the manifold to the reed cage because they have a die grinder to properly match the parts. This can cause a loss of power from the gross mismatch.
The bottom line is that V-Force reed valves don't work on everthing and there is a lot of customization involved in making them working like they're intended.
My advice is if you don't have the skills or patience buy a RAD Valve instead.

The sadest thing about Eric's whole statement is that it's all true. I can't tell you how many times i've seen it happen to young kids ( and even older kids..that's us) that were looking to use aftermarket equipment to make a performance difference. owning my own shop subjects me to the same stories that Eric is talking about. atleast once or twice a year some young kid will walk through the door of my shop and the wonderful words of " excuse me, uh do you guys know anything about nitrous oxide systems?" come rolling out of there mouths. "We sure do but i'm more prone to doing regular automotive work, but what is it that you need?" well brand x sold me this kit for $400 bucks and it doesnt work right. No problem man let's take a look and see what you got. well they sold you exactly what you asked for, a nitrous kit, not the other $1,000 worth of things you need to make it work right or the knowledge that goes with it all. let's remember these places are in the market to make a sale (hence salesmen answering the phones). Some of these guys would sell out their own mothers!!!! It's sad to say but i'm sure these scenario's have happened to all of us with one thing or another. It's just sad that everyone of them have the same slogan: " sure that will work...Goes on with no modifications what so ever." till they get the tech call and they say oh ya 2003 fliperty gib right??? yeah we seem to be having that problem with just that year bike!....... go figure

 

[DEANSFASTWAY]

Yeah : Im feeling you , Ive also had the pleasure of witnessing the manifolds come unbonded after the installer kid cut out the reed stuffer part. Maybe they should just make a whole manifold? Seems those MT reeds dont last very long either. Plus half of the kids that install them dont even know how to jet or get their bike running crisply anyway so when they change parts sometimes they are going even farther in the wrong direction. But I guess thats what its all about trying things and learning trying and learning . just that sometimes some people dont really learn they just spend money. The WORLD keeps turning.

 

[jmics19067]

I have fitment problems with V-force also. The screws that hold the thing together didn't fit in the cylinder without notching the cylinder In 4 spots just a tad. 94 yz/wr

I do not like the instructions that they give you with how to cut the reed stuffer either seems all too easy to hack up the sealing area. Luckily a 94 yz has no reed stuffer like the wr. So that part was cake walk for me.

I have not done any back to back testing yet about performance so I am not sure if all was worth it . Though the 40$ extra or whatever it is for a rad valve seems awfully enticing considering it is a direct bolt on and you leave the existing stock stuff left in stock condition.

 

[Zenith]

I'm sure Moto- Tassinari would be willing to help you out in whatever way they can

Don't count on it! I was in contact with one of their guys via email about my reeds fraying VERY quickly; he was helpful at the start then said he was passing it on to the tech people. I never got another email from him and nobody else there would reply to my emails. What ever happened to customer service!?
My VForce "nearly" fitted into my 00CR125 perfectly, just took a bit of encouragment, no grinding though. The manifold to cage matching was pretty lousy though, a bit of grinding required there...

 

[mxneagle]

In all I'm very happy with my V-Force, however I was shocked when I read that they wanted me to cut off the stuffers with a hacksaw. I used an exacto and surgically removed them instead. I had no problems with fit either (maybe the 2001 CR250 was one of the bikes they designed for). I've run the bike for 2 years and now I finally had a reed break, that's not bad IMO. The symptoms of a broken reed are strange with this setup though. The bike ran fine on bottom and was responsive when "bliping" the throttle but ran like it had a fouled plug if you held it wide open

 

[jski]

Thanks guy's,

I got it to fit but now it is seeping a very small amount of fuel along the bottom.

BTW I went to the local shop and we checked 10 CR-500 cylinders for fit and the valve did not fit any of the 10. The guy at the shop also said they were having problems with the fit on the snowmobile reed cages.

It looks like the mold for the cage is at the high side of the specification for the cylinder

 

[jmics19067]

if you can see fuel leaking out of the gasket area is something I would be extremely wary of. Since you are trying to draw air fuel mixture into the engine you probably have an air leak also.

 

[DEANSFASTWAY]

Wow what shop has 10 CR 5 cylinders in stock?

 

[jski]

It was 2 of our local machine shops that does most of the boring and honing for all of the shops here in Utah. Well I also took Eric's advice and went out today and bought a Rad Valve because even with new gaskets I can't get the V-Force to stop seeping gas. I'll try to use the V-Force in my 87 500 because all we use that bike for is hill racing so will see if it seals in the 87.

 

[kbud]

ya know, i seem to recall a Dirt Rider test that they had to do some filing on the reed valve to get it to fit. could this be the prob?

 

[ericlachance]

jski could you give me your impressions on the rad valve once you install it? fit and finish? But most important, is it worth the price? I wanted to put one on my 96 yz250 but wanted to make sure it was worth the price before. Theres no way im cutting anything on my bike, so screw the v-force!!!!!

SS

 

[Superchief]

Moto-Tassinari changed the whole design for the 03 CR 250R. I did'nt have to modify anything to install the reed cage, and did'nt have any fitment problems either. I would'nt count on it, but Maybe they are learning their lesson???

 

[nephron]

My advice is if you don't have the skills or patience buy a RAD Valve instead.

lol, I got the sense from Tassinari's pictures and data that they 'copied' a blueprinted design idea and just sort of hacked sizes for the various bikes. Their site is uninformative, etc.

I went with Boyeson because:

A) He's an old Norwegian dude that races to this day
B) He still does the majority of the designwork and dyno time
C) He obviously loves what he does
D) There's a completely different design from bike to bike, that seem to account for that particular bike's power outlay

...I just like the idea that he's an old racer that loves what he does and does a great deal of the work himself. Mine is great, and went in without any modifications at all.

 

[Anssi]

We got a RAD valve for my dad's 380 SX. Fit without any problems or filing or hacking. Couldn't tell if it made any difference, he just had the need to spend some money on the bike.