Burned rave valve cap and piston

[Drackodude]

Hey there, well... i just took a look at my engine today to to my check up before leaving...and i just noticed my PTO rave valve cap was crooked. I removed the rave cap to see what was going on.... and the cap was completly melted in the Inside and the piston too. The last ride i took i noticed when i put the throttle to far it seems to almost stalls but runs fine at low speed when i don't give it juice.

Anyway.... what can cause this to melt? (((leaking rave seal?))) Could my loss sudden of power when i accelerate be this problem?

Will be removing PTO rave valve tomorrow and hope the rave blade is ok.:facepalm:

 

[Danosll]

I too had this problem . The first time it occurred I changed the valve guillotine and oring with oem parts =$$.which here in Quebec are hard to find. It turned out the culprit was the housings themselves . The bore was worn. Allowing hot gases past and melt the soft parts. I replaced everything with SBT aftermarket parts 1/4 the cost then oem . And nobody around montreal or ny had in stock . IPlaced ordered 2:00pm received it next day 11:00 am $40 bucks shipped by FedEx. So check the play with your valve and housing .

 

[Danosll]

This a quote from a reply I received from waterluvr..Found that reference for clearance, the source was cited as having been copied from the Sea Doo racing handbook:

"Move the valve side-to-side while it's in the housing. If it moves more than 1/4" either way, you must replace both the valve and the housing. If you continue to use the valve, you could wear away the cylinder clearance for the valve. If you are really mechanically inclined. Take the removed valve and stick it into the port. Take a 0.17 feeler gauge and put it in-between the valve and the cylinder. If there is more clearance than 0.15", then the cylinder has too much clearance for the valve to function at it's peak level. If this is so, then the cylinders must be completely replaced if you wish to get the maximum amount of power you can out of the valve."

 

[Waterluvr]

Rave valve housing wear is the likely culprit so long as the o-ring was in place, measure the hole in the housing if it's over .400 replace it, the complete valve with new everything from SBT is a really good value to get those working dependably again.

 

[Drackodude]

Bad rave valve

I too had this problem . The first time it occurred I changed the valve guillotine and oring with oem parts =$$.which here in Quebec are hard to find. It turned out the culprit was the housings themselves . The bore was worn. Allowing hot gases past and melt the soft parts. I replaced everything with SBT aftermarket parts 1/4 the cost then oem . And nobody around montreal or ny had in stock . IPlaced ordered 2:00pm received it next day 11:00 am $40 bucks shipped by FedEx. So check the play with your valve and housing .

Well got it off today.... the housing center bore was damage... even the shaft of the valve itself was damaged.. you can see wear were the shaft goes into the housing... so ill be replacing every thing (housing, valve, cap, piston) I got to be honest with you im a bit worried about the other rave valves... i've heard that they can destroy an engine quick.

Will send pics soon

 

[Danosll]

If shaft breaks valve won't touch piston