Cracked intake manifold

[eric_f]

Oh wow, I totally missed all of these replies

I found the plate on eBay and ordered it. It arrived today and I went to install it and while I was torquing the head bolts back in, one of them snapped
I guess now I gotta find a new bolt. Maybe I should just replace them all.

I've found the part number 90119-08019-00 for the OEM bolt and a handful of other suggestions for other bolts, but I'm not sure if they're the same. I'm still rocking the 650 and I'm not sure if the 701 head bolts are the same or not.

 

[Pro-pulsion]

Hey all,

I've had my '91 Superjet out on the lake about 20 times this summer, and the last few times it's been running really poorly. I've been chasing down issues and working to resolve them. Nothing has made the difference I was hoping for. Today, I decided to run a more in-depth health check and found that I've cracked my intake manifold in two places. It's a 650 single carb, and on both sides where the studs are, it's cracked. I'm assuming it's because the aftermarket flame arrestor has been installed and the carb is no longer attached up top, causing the vibration to finally overcome this weak point and break.

Besides replacing the manifold, are there any other suggestions for ways to improve the strength so this hopefully doesn't happen again?

Weld it. Take it to a machine shop and ask if they'll weld it. They can do cast aluminum, I've had it done many times. While you're getting the repair done also ask if they can do a gusset style weld buildup to give it more strength.

 

[JetManiac]

Oh wow, I totally missed all of these replies

I found the plate on eBay and ordered it. It arrived today and I went to install it and while I was torquing the head bolts back in, one of them snapped
I guess now I gotta find a new bolt. Maybe I should just replace them all.

I've found the part number 90119-08019-00 for the OEM bolt and a handful of other suggestions for other bolts, but I'm not sure if they're the same. I'm still rocking the 650 and I'm not sure if the 701 head bolts are the same or not.

650/701/760 all use the same cylinder head bolt.

 

[eric_f]

650/701/760 all use the same cylinder head bolt.

Thank you!