Dead 045 stihl into a super!

[spookum]

Hello! I have been lurking for a while. But recently I tried to repair a broken case on a 045 AV...



Long story short... TIG WELDING WAS NOT AN OPTION (the weld broke during cooling) and I noticed the outer race was spinning in the bearing. Strike one and two. While I had the exhaust off I used the old calipers to check the piston dismayed and it was a shade under 50 mm. Strike three.

Good old fleabay to the rescue. I have a new used case on the way to alaska and a 54mm jug (140# of compression i was told) with piston on the way too.

I guess I have a few minor questions. The first of which I know this has been done before.... So any mods to the carb at all? The part numbers are all the same as far as I can tell.... I just have experience with snow mobiles and I know I can tune it right on the top end... I just don't want to burn it up on the midrange. Also, I found a base gasket for the jug, it is for a 056 magnum. One would think this could work, I just worry the gasket could be thicker/ thinner the. Stock. Thanks for the help, and nice to meet you!

 

[blsnelling]

The Super topend is a direct bolt on replacement. Nothing else needs to change.

 

[torinocobra]

The mag gasket won't work unless it can be trimmed to fit. The bolt holes are farther apart.

 

[blsnelling]

The Mag is different but the Super is the same.

 

[spookum]

Thanks guys! Anyone know where I can find a base gasket?


That jug should take a 54 mm piston right?

 

[blsnelling]

Yes, and those pistons are hard to find.

 

[spookum]

Pistons are easier to find than base gaskets!!! Hahahaha

 

[spookum]

So the the new jug showed up today. Super happy!!!! I can STILL SEE HONE MARKS ABOVE THE EXHAUST AND INTAKE PORTS!!!!

Any hoo I thought I would try my hand at polishing up the intake and exhaust ports. The intake port is SUPER weird... One wall sticks out 1/4" easy to straiten that out.... there is this hanging chunk of alumanum.... Hmmm.... Any reason not to take it out???? And chamfer it back to match the port? I'm not going to open the ports up any inside of the cylender.... Just open and polish them and get the exhaust to breath.

Offending hangover thing:



From the inside



Thanks!!!

 

[Rookie1]

The little doodad is there to keep the ring in the groove when the piston comes down. I believe others have ground it out with mixed/bad results. Keep up the pics and progress!

 

[scallywag]

I've been told not to touch that 'hanging chunk of alumanum'?......looks like a tonsil, right?.......for some extra flow, you might try a super/mag twin port muffler and a magII carb, also drilling some extra holes in the air box cover will help.

 

[scallywag]

Offending hangover?.....heres me thinking that you'd been on the booze.

 

[spookum]

.. Looks like I'll be leaving the tonsil alone! But it looks like I can get minimum gains from just straiting out the intake port and opening up the exhaust..... I know it is over kill but I have to start small.... thanks for the advice guys!

 

[spookum]

Here is the piston. Replace it with a GOLF piston or run what I got?









Thanks!!!!

 

[kyle.kipple]

I have cleaned worse looking pistons. Remove the rings and sand on it a little bit, it doesnt look too terrible. Install new rings should be fine after a little rubbing out.

 

[spookum]

Hi guys! I think I am going to try to reassemble without a base gasket. What should the maximum squish be.... I'm looking for an answer that .015 Is iffy. But .020 is fine. ...

Thanks.

 

[spookum]

Can I cut out a beer can gasket to make it perfect?

 

[spookum]

Crickets? Can I run no gasket?