I could be wrong but l would be looking at ignition problem or propane

My compression is 180, 170, 165, and 180.

Bill l though this was an 2.0mazda fe engine that used a belt what l think you are working on is a d5 Mazda engine this motor used a chain they did hope this helps.not use many of them in forklifts the fe was more popular l had done a couple head gaskets on them but l don't remember doing a timing chain l know to do it you have to pull the hole front of the engine down also in the front there is a small plate that comes off in there is a timing chain tensioner that has gear teeth to tighten the chain if the chain was that loose the tensioner would pull out all the way.also if you take the chain off the cam with the gear becarefull the tensioner will walk out and you will then have to pull it apart.l would turn the engine untill the number one piston is at tdc and the number one intake and exhaust are closed then take the dist cap off and see if it is firing on number one cylinder.also if the chain jumped you probably have low compression in all cylinders take a compression test and see if the compression is good.hope this helps

This engine has a timing chain.

Bill truck uses a timing belt remove the upper cover and loeer cover after that you will see the Cam gear it has letters on it it should be at 12 o'clock with the letter A stamped on the Cam gear. On the crank there will be a notch in the gear that should line up with a mark on the bottom aluminium plate it to should be at 6o clock then the disttributor should line up with number 1 on the dist cap hope this helps