How much heat on bolts is too much?

[rockb]

I have a 1986 115 Suzuki that needs a new water pump.

The bolts are TIGHT. I have gotten two out and am pretty sure that I have broken two.

I have heated them with one of the 1lb Propane bottles with a brazing nozzle. That is what freed up the two that I have gotten out. My question is on the other four how much heat is too much. I have heated them each about 30-45 seconds a couple of times but they still will not budge.

Thanks in advance.

 

[solar7647]

Re: How much heat on bolts is too much?

Have you tried a breaker bar to get more leverage? If you dont have a breaker bar use a pipe to slip over a socket. Also heating the bolt only makes it expand, you would want to heat what ever the bolt is screwed into to make that expand so it releases pressure from the bolt, but i dont know if thats possible in your case.

 

[rockb]

Re: How much heat on bolts is too much?

Have you tried a breaker bar to get more leverage?

Yes. I'm pretty sure that is how I was able to break the two that I am pretty sure I broke.

 

[capt sam]

Re: How much heat on bolts is too much?

What I usually do is try to squirt some PB Blaster on them and let them sit a while and then heat them with a torch, usually several minutes and then try them and reheat if no give, it usually takes a few applications then works. Just be careful the metal around the bolt doesn't get too hot but it takes alot to damage it.

 

[rupertmja]

Re: How much heat on bolts is too much?

Be careful, a good torch may melt metal. Heat it up and turn the bolt a fraction. Once there is a bit of movement, tighten it back the same fraction and wiggle it back and forth a tiny amount. Then, if it frees a little, once it turns, even if a little tight, just go for it and keep turning it without stopping - go for broke (handy to have another person still applying a little heat). It usually works for me but I still break the odd one. For the broken ones, file or grind the top's flat, centre punch them, and drill them out with a smaller size drill. If you hit dead centre - not easy - you might get it all out and be able to reuse the thread. If not, you'll need to tap it out to the next size, or, helicoil it.

 

[gill]

Re: How much heat on bolts is too much?

heat the metal around it as hot as it will get, propane will not get hot enough to do any damage. I usually use oxygen/acetelyne on my stuck bolts

 

[rockb]

Re: How much heat on bolts is too much?

OK Got all the bolts out. Now what. I have heard horror stories about hitting the cavitation plate and breaking it. So other than that how do you break the foot loose?

 

[momentum]

Re: How much heat on bolts is too much?

if the motor has a mechanical shift did u remove the bolt holding the shift lever? if u did remove bolt
is the leg moving down at all if it is not it may be a frozen drive shaft which is not a good thing but it is possible to remove search the forums for frozen drive shaft im sure i have read a post on here some where

 

[rockb]

Re: How much heat on bolts is too much?

if the motor has a mechanical shift did u remove the bolt holding the shift lever?

Yes I disconnected that and removed the bolt holding the Zinc

 

[99yam40]

Re: How much heat on bolts is too much?

How many bolts did you end up breaking off?
Is there corrosion around the remaining broken pieces holding everything together?
I have seen it where the broken bolts had to be drilled just to release the lower unit when they were corroded bad enough to cause them to break off.

Usually I hit with a rubber mallet and if that does not do it , I will use a real hammer but hit a piece of wood not the casing.

 

[robert graham]

Re: How much heat on bolts is too much?

Make sure you check/remove all bolts, may be one under zinc trim tab and another under small rubber plug under cavitation plate. Good Luck!

 

[JUSTINTIME]

Re: How much heat on bolts is too much?

PB blaster and heat

SUZI has crap metal

 

[rockb]

Re: How much heat on bolts is too much?

Make sure you check/remove all bolts, may be one under zinc trim tab and another under small rubber plug under cavitation plate. Good Luck!

I got all the 8 obvious ones and the one that holds the zinc. Where is the rubber plug you are talking about under the cavitation plate? Can you direct me to it based on the pic below?

 

[capt sam]

Re: How much heat on bolts is too much?

when you remove that plastic cap to access the trim tab bolt there's also a bolt there for the lower unit.

 

[rockb]

Re: How much heat on bolts is too much?

when you remove that plastic cap to access the trim tab bolt there's also a bolt there for the lower unit.

trim tab?

 

[capt sam]

Re: How much heat on bolts is too much?

the zinc on your cavitation plate.