RAVE valve problem

[98_SPX_PWC]

First of all hi :hurray: looks like a good place :thumbsup:


Anyways, I was cleaning my Rave valves in my 98' SPX (787 engine) and I noticed a serious problem. (see pic) From what I can tell is that the piston and the guillotine collided cracking a descent size chunk from either side of the guillotine. How this could happen I'm not sure but maybe someone has seen this before.

I was goin through the PWC because my brother was riding it and it ran great at start of season and next day when riding it for about an hour he said it just bogged down without having much power or rev capabilites, making me think the carborator had become plugged or something else related to fuel delivery.

After looking at the valve it makes me think a chunk of the guillotine broke inside this engine also leading me to think I may be up crap creek at the moment. I couldn't see any remnants in the piston chamber looking through the little slot were the guillotine slides into but that definitely doesn't mean that there isn't something in there.

Basically, what my question is, what should my next course of action be? I have the service manual for this thing and I'm not to worried to dig a bit deeper. But I haven't really done much to this thing so I'm a bit blind here. My biggest question is if something did break off in the engine shouldn't the rider (my brother) been able to notice a very severe grinding noise then death of the engine in fairly rapid order? Is it possible that it has been running this way for some time?


BTW this pic shows the rave valves descently clean, they were filthy and locked up before cleaning**

 

[Dr Honda]

I would pull the head off the engine to see if there is piston damage. You may have gotten lucky, and the busted RAVE parts went out the exhaust... but you may have caught a bigger problem before the engine ate itself.

 

[98_SPX_PWC]

I would pull the head off the engine to see if there is piston damage. You may have gotten lucky, and the busted RAVE parts went out the exhaust... but you may have caught a bigger problem before the engine ate itself.

I'll take it off this evening if I can find some time then post a few pics from the inside of the crankcase

Thanks

 

[98_SPX_PWC]

crankcase pictures

Ok I went and opened everything up tonight and here are the pics. I included one picture of the dirty rave valve as I was removing showing that some dirt fell from the sides and into the crankcase. There is also alot of carbon buildup and scale inside the slot in the crankcase where the guillotine slides into and I should probably clean that as well. In the 2 closeup pics of the cylinders/pistons you may notice some black dirt on the bottom. This was caused from removing the rave valves and some fell into the cylinder.
I'm no expert in judging a cylinder wall but it seemed glassy smooth all around on both and maybe a visble line where a slight score is going on but not noticeable with your hand. What bothered me was the amount of carbon buildup on the piston but this may be normal for an engine this age.

All the pics are in a photobucket album. Let me know if you have any trouble viewing them. Thanks

http://s1172.photobucket.com/albums/r576/npinson90/new/

 

[98_SPX_PWC]

I'm having problems uploading from pics from my computer and I have also tried loading from an URL but no go there as well. Resizing doesn't seem to help. I get an error code everytime.

 

[Dr Honda]

Open a PhotoBucket account. It's free, and all you do is post the IMG link on their web site.

 

[98_SPX_PWC]

I tried the uploader and it worked this time so all's well

I took the head cover off and I didn't see any severe damage. The rave valve slots and the rave valves themselves were filthy and as I pulled the guillotine out some dirt fell into the crankcase so the dirt you see in the pictures is from that. The cylinder walls are glassy smooth and seemed fine to me. There were maybe a few very light lines in both cylinders but nothing that seemed to be caused from the broken guillotine valve chunk flying around in there. I couldn't reallly feel the score marks, it was easier to see them, so it looks like it may be normal wear.

I'm not expert on judging a cylinder wall for problems, but to me they seemed to be in descent condition, at the very least the engine should still run in it's current state.

There was alot of carbon buildup on the pistons but this may be normal for the age of the engine I guess? I couldn't see any visible dings or dents in the piston itself.

Any thoughts welcome.

Regards,
NP

 

[98_SPX_PWC]

Open a PhotoBucket account. It's free, and all you do is post the IMG link on their web site.

Ahh I do have one and tried that too and it wasn't working either so idk

 

[ltdyfz99]

you got lucky and shot that sucker out, get a used rave off ebay or if you need I might have a slotted one for cheap. Do your self a favor and rebuild them, new everything related to the raves is the only way to go and since your there why not just pull those cylinders off and flex hone them so you can run a fresh set of rings that way your top end is rebuilt for this season. I usually find my self just doing rings more often then letting my cylinders getting oval and require bore jobs.

 

[griz400]

you should buy a lotto ticket, you got lucky on this one, shake your front pipe around and see if pieces are in there -- put a rave in, also check and see if the shaft on that broken one is lose in the housing compared to good one, what happens is the housing wears and valves "chatter" and break sometimes.. did you happen to check compression before takin it apart ??? if it was good, i would just put er back together, with a new rave, and (shake and bake) lol , thats what ricky bobby would say

 

[98_SPX_PWC]

you should buy a lotto ticket, you got lucky on this one, shake your front pipe around and see if pieces are in there -- put a rave in, also check and see if the shaft on that broken one is lose in the housing compared to good one, what happens is the housing wears and valves "chatter" and break sometimes.. did you happen to check compression before takin it apart ??? if it was good, i would just put er back together, with a new rave, and (shake and bake) lol , thats what ricky bobby would say

Thats kinda what I'm thinking. New Rave parts, new rubber gaskets for the head. My brother ran old gas mixed with new lower grade gasoline through it at the start of season so the carbs may need rebuilding. He also refueled at the marina gas service pump once, maybe twice and I sometimes question the quality of the fuel. I've heard of water condensation in these types of tanks and may have had really bad gas run through?

Thing is that it ran great first day out then next day it was running choppy. It was docked in the water overnight as well.

And no, I did not check compression before removing which wasn't too bright. I was assuming a tore up cylinder so I didn't even bother. :banghead:

Could sticking rave valves cause noticeable engine problems?

thanks

 

[98_SPX_PWC]

you got lucky and shot that sucker out, get a used rave off ebay or if you need I might have a slotted one for cheap. Do your self a favor and rebuild them, new everything related to the raves is the only way to go and since your there why not just pull those cylinders off and flex hone them so you can run a fresh set of rings that way your top end is rebuilt for this season. I usually find my self just doing rings more often then letting my cylinders getting oval and require bore jobs.

If it comes to this, what is the time involved to remove engine, replace parts as necessary, and realign engine/shaft?

 

[ltdyfz99]

You wont have to remove the engine to do the top end, you already got what you need off. Just pull the cylinders off with the exhaust manifold, buy a flex hone for a 82mm, order some rings at 32.00 a pair on eBay WSM brand. A base gasket with the required hole amount, make sure you check how many you have on the gasket when you pull off the cylinders. If you have all the parts you can bang it out in a few hours, just remove the bottom pipe from your motor to check if you got some rave junk in it, if not it went into the water box.

 

[LouDoo]

If it were me I would buy two new rave valves, I'm betting the good rave is not far behind. Keep the old good one for a spare.

Lou

 

[98_SPX_PWC]

You wont have to remove the engine to do the top end, you already got what you need off. Just pull the cylinders off with the exhaust manifold, buy a flex hone for a 82mm, order some rings at 32.00 a pair on eBay WSM brand. A base gasket with the required hole amount, make sure you check how many you have on the gasket when you pull off the cylinders. If you have all the parts you can bang it out in a few hours, just remove the bottom pipe from your motor to check if you got some rave junk in it, if not it went into the water box.

What grit type and number (200,320,400?) should be used ?

On brush research's website an 83mm brush with silicon carbide with 320grit lists for $57

http://www.brushresearch.com/brushes.php?c1=2

 

[ltdyfz99]

And please buy new rubber boots, they wear out and cause issues you dont need. Its cheaper just to buy a rebuild kit for the raves

 

[El Toro 33809]

Could sticking rave valves cause noticeable engine problems?

thanks[/QUOTE]

Yes, the rave valves change the exhaust timing. A broken or stock valve will impact performance. Luckily it is the exhaust and if one breaks the natural tendency is for it to be spit in he pipe.

 

[98_SPX_PWC]

Does anyone have any opinions about non OEM guillotine blades for the RAVE valves? It seems like the only OEM blades on eBay are used/dirty and the new ones are all OEM-Replacement. Could just go to the dealer but I'd like to know what my options are first.

 

[98_SPX_PWC]

Edit** Content deleted