Broken Bolts

[jcare]

I have a DT140 that I bought used at the beginning of last year. Was told that it has been a freshwater engine, and that is my use as well. Went to replace the impellor this past weekend and broke two of the four bolts that hold the water pump housing in place. <br /><br />I have removed the lower portion of the water pump, and do not have much bolt protruding from the lower unit. I have tried heating with Mapp gas torch, but it still will not move. I do not have an oxy torch to try to heat up more. Should I try to take to a machine shop to have removed or drill and heli-coil them. I have read on here about heli-coils, but never used them. Not sure how to purchase (size etc)<br /><br />Also, should I replace the O-ring and oil-seal on the lower portion of the water pump leading down into the gear case now?<br /><br />Worst part, the impeller look in good condition. Thanks

 

[tashasdaddy]

Re: Broken Bolts

impeller can look good, and disitergrate when reinstalled.

 

[jcare]

Re: Broken Bolts

Rodbolt or Ray, what about removing the bolts. Will drilling and attempting to use an easy out just be a waste of time without a hot enough torch?

 

[rodbolt]

Re: Broken Bolts

using an easy out is a waste of time period, takes longer to extract the broken easy out than the original drill out.<br /> the heli-coil kit comes with the tap,inserts, installer and some have the insert drive tang break off tool.<br /> the heli-coil size is determined by the fastener, yours will most likly be 6mmx1.0 or 8mmx1.0mm. but its up to you to measure the thread pitch and diameter.<br />the heli-coil tap will have the correct drill size printed on it.<br />myself I file the broken part flat and accuratly mark the center and use the correct size tap drill and drill the fastener out.<br /> I have made a few drill guides but for one or two I usually free hand them, the key is good quality bits and cutting oil, lots of oil.

 

[gss036]

Re: Broken Bolts

I just went through this with a Honda and I used a cobalt 1/8" to get a hole completely through the bolt, then worked up in size w/o getting into the threads and then used a small center punch on the side and was able to get the threads to break free and took them out w/ needle nose pliers. If that had not worked I was going to heli-coil, but skated on this one.

 

[P2]

Re: Broken Bolts

I have also had good succes with using a " left hand " drill bit to do the initial drill out's. Some times the heat caused by the drilling will spin the broken fastener right out for you.( use a good cutting fluid also) And if not you had to drill the hole anyways, nothing lost and you may get it without retapping<br /> good luck