i have a mudbuddy 6000 hd with iron mountain head. it only has 27 hrs on it and i have had many problems with it. i have had a cracked rod and a burned up oil pump that i had replaced and now i cant keep it firing on both cylinders. i originally bought it and it had pro flo heads but i was talked in to "upgrading" to the iron mtn heads and i have had problems ever since. any advice on what to do or how to keep the heads from sticking and both cylinders firing?

Hmmm not good news!

I'm concidering going with the Iron moutain heads myself and have heard nothing but good reviews on them.


When you say cracked rod what rod are you talking about? The connecting/piston rod or push rod?

I could be wrong but by reading your post a red flag goes up saying bad oil pump = potential internal engine damage if not caught early on. Did you find the bad oil pump while fixing the rod?

The firing is a totally different part of the system , something might have gotten pinched ( wires) during reassembly or you might have a bad diode.

Hope it turns out to be something simple for ya myboy. Good luck!

As Preston stated, the ignition firing is a different part of the system. Assuming you don't have any gasket leaks on your heads here are some things to try from simple to more involved.

I talked to a guy in your area not long ago that had a similar sounding problem on his HD7000 (which I think is just an HD6000 with the IMheads). He was sure it was his ignition but it ended up being a bad tank of fuel. You can first try a short fuel line right into a gas can of fresh fuel and see if thats your problem.

The second thing to to try and isolate is the Rev Limiter- if its going out it may cause intermittent misfiring. Usually they either work or not but you can isolate that variable by disconnecting the Green wire on the rev limiter to take it out of the equation. Just be careful with your throttle so it doesn't over rev when you check it (especially out of the water- no more than 1/2 throttle and take it up slowly). A good practice is to put a spade connector on the Green wire on the rev limiter so you can easily disconnect it if the motor is not starting.

Finally- make sure you are getting consistent good spark at each cylinder. Use a spark tester of have a mechanic check it. Each of your coils has a wire connecting to a spade connector on the coil base. The wires have a diode on it at each coile and is where the coil is grounded to kill the motor when the key is turned off, kill switch activated, or oil pressure sensor is tripped. If the harness is bad or a wire is pinched and intermittently grounding, it will be causing a cylinder to misfire. When there is a single carb on the motor, this harness is held out of the way of the fan and such with tie wraps on the intake manifold. I am not sure how they do this with the dual carbs but you can try to isolate the harness by disconnecting the wires to the spade connectors on the coils and see if it runs well. This is pretty involved to take off the cowling to get to the coils with the dual carb setup compared to the single carb. If you run it without the harness connected (and cowling off) be careful of the fan blades and note that you will not be able to turn the motor off with the key or kill switch- you will have to choke each of the carbs or use insulated gloves to pull the plug wires from the spark plugs to turn it off.

Hope this helps.

Wow... MB is having issues with their modded motors also.... You don't hear about that too much... Nice to know everyone has their fair share of issues. Did MB help you out when you called them or you haven't had a chance since this came up over the holidays.

All of them have issues but the 45 base motor has been very reliable.

deadbird i heard you got a nice christmas present!

no thread jacking intended


carry on...

it was a piston rod that was split, and we caught the oil pump while we were testing the engine after we replaced the rod. as for the revlimiter i have one on the way to replace the stock one, also i am replacing the spark plugs and adjusting the carbs. lwt mw know if theres any thing else that i need to do.

is the revlimiter on a MB 6000 suposed to mae a sound when theres power going to it. I just got a new one and it makees a ticking sound .