Trouble with 145.23 repeater

This repeater has been decommissioned.

I was using two FT-60Rs for the receiver and transmitter (2 watts) when I realized the transmit FT-60R was getting overheated enough to either go into thermal shutdown or blow up completely. Yaesu has probably the best real-world selectivity of  HTs on the market. I have yet to have a problem with them along Intermod Alley (Hennepin Avenue from South 10th St. to Washington Avenue), however, using the FT-60R for a low power repeater is just not feasible. I have two FT-277Rs that I'm planning to use for a 70cm repeater. The 277Rs are larger and built like tanks, so they may be able to withstand the heat, leading me to believe that I should never have sold my FT-270R to begin with. I placed a TM-271 (adjusted for 2 watts) on the transmit side. An FT-60R was still acting as a receiver. No problems. When I replaced the FT-60R with my TM-281 and configured the 271 to output DCS 612 and keyed the repeater, the system went in a loop. Changing DCS to another code didn't help. Changed to 127.3 hz and the system acted normally. Curious. Though Repeaterbook shows D612, use carrier squelch to receive the repeater for now.

UPDATE: Removed the ground to the TM-271 (transmit side) and that resolved the problem. The controller is a Reed Electronics u-Controller that is designed to be used with HTs. I ordered an ID-O-Matic III. If there is no loop problem with that controller with the Kenwood units, I'll use the u-Controller and the FT-277Rs for the 70 cm repeater.

I am also keying another repeater. The two other repeaters on 145.23/144.63 are K0LAV (Gem Lake 94.8) or Maple Lake (W0EQO 114.8). CW ID indicates it is KA0JQO/R.

UPDATE: Apparently there was a cross band operation on another repeater and KA0JQO/R was linked.  It was a problem with another repeater and is now resolved.

A few points:
1. The MRC Coordination Manual states on page 10 that "144.630 Mhz input and 145.230 Mhz output will be coordinated in the State of Minnesota for use by repeater stations on a shared basis (Shared Non-Protected). No geographical separation from other repeater stations in Minnesota using the same frequency will be done. All stations using this pair must use CTCSS, digital CTCSS or DTMF access [emphasis added]. The tone to be used for protecting the repeater input must be given to the Repeater Frequency Coordinator".
2. I was trying to find out source of the problem. A carrier-squelched repeater on an SNP frequency can cause all repeater operators a headache . IOW, I was doing the right thing.