Stihl HT 75 what do you guys think....

[trooney]

Now, this is the scenario. Bought an HT 75 at auction. The extension is good, motor had an air leak, wouldn't oil. Put a new seal in it, took out the oil pump and cleaned it up, all gunked up with stuff. Heres my dilemma...when it had an air leak could get it up to about 9,900 rpm. Close. Air tight I can get it up to 8,700 rpm. I think specs on it is 10,500. New Zama carb. Is it in the ignition possibly or possibly remive the limiter cap and see what I get. Its kinda wierd that it would get more rpm with an air leak than without. What do you guys think?

 

[backhoelover]

could be those coil has stage in them. also have you check the tank vent and made sure the ex port and muffler is clean?

 

[backhoelover]

stages

 

[trooney]

Thanks for your reply. The tank doesnt seal, leaks some fuel, but where is the tank vent? Take a look at it when its all apart. I'll order a new coil and try that.

 

[trooney]

Muffler is good, no screen and holes opened up.

 

[backhoelover]

have you remove the limters. if not if would see what adjusting will do.

 

[trooney]

I'll buy a coil and if that doesn't do it, on to the minuter caps

 

[trooney]

Limiter

 

[dbittle]

I think I would pull the limiter caps and re-tune, and possibly check the carb metering lever height to make sure it's not too high. If its too rich with a new carb, outside the normal limiter range, there is possibly a reason why.

 

[bikemike]

Now, this is the scenario. Bought an HT 75 at auction. The extension is good, motor had an air leak, wouldn't oil. Put a new seal in it, took out the oil pump and cleaned it up, all gunked up with stuff. Heres my dilemma...when it had an air leak could get it up to about 9,900 rpm. Close. Air tight I can get it up to 8,700 rpm. I think specs on it is 10,500. New Zama carb. Is it in the ignition possibly or possibly remive the limiter cap and see what I get. Its kinda wierd that it would get more rpm with an air leak than without. What do you guys think?

Get rid of the spark screen

 

[Lone Wolf]

Try the RPM's with the air filter out maybe it's clogged.

 

[trooney]

Air filter is brand new Stihl. Both pre and filter. Spark screen has long been gone on this puppy. Down to ignition or limiter caps. Unless its a tank vent, but I doubt it.

 

[Lone Wolf]

Air filter is brand new Stihl. Both pre and filter. Spark screen has long been gone on this puppy. Down to ignition or limiter caps. Unless its a tank vent, but I doubt it.

Limiters could do it. Tank vent can be tested. Does it seem to run OK or lack power?

 

[trooney]

It runs ok, but you've got to turn the L out to about 2 turns, and it only revs up to about 8.6 k. It should be about 10.5, or so I'm told. It throttles up alright, just wont get up to speed

 

[67L36Driver]

My HT75 is no speed demon.

I have a top end kit and a carb for it eventually.[emoji849]

 

[Lone Wolf]

It runs ok, but you've got to turn the L out to about 2 turns, and it only revs up to about 8.6 k. It should be about 10.5, or so I'm told. It throttles up alright, just wont get up to speed

Take the H limiter off and put the low back and turn the H out and see what happens.

 

[trooney]

It wont start if its 1 out. About 2 is where it will start. It seems like a fuel issue but the lines are new , the gas tank leaks so it cant be holding vacuum, and its a new carb. Of course the Chinese pieces of crap, you cant tell if its a real Zama or a knockoff.

 

[trooney]

My HT75 is no speed demon.

I have a top end kit and a carb for it eventually.[emoji849]

If this doesn't fix it I'll run it as is

 

[67L36Driver]

If this doesn't fix it I'll run it as is

I've been doing so. Just takes patience.

Hate to mess with it actually as once started (easy!) it will sit there and idle 'till it runs out of fuel.

 

[Lone Wolf]

It wont start if its 1 out. About 2 is where it will start. It seems like a fuel issue but the lines are new , the gas tank leaks so it cant be holding vacuum, and its a new carb. Of course the Chinese pieces of crap, you cant tell if its a real Zama or a knockoff.

It could be a China crap one.