GS850G 1981 with runaway throttle... scary.. whats wrong with it?

[Steve]

I would think there would be too many shavings, but I have never done one, so can't say for sure. :-k

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[Wallowgreen]

Few years back I did a time sert in a stripped plug hole on my 250 without removing the head. Never had any issues with it since, plugs have been out many times without issue.

Use lots of grease and clean shavings off regularly. Take your time and you should be fine. When I did mine I was told one or two shavings in the pot isn't too much of an issue being soft Aluminium but not sure I believed it. Either way I didn't rush, made sure all was good at every stage, wiped everything down often then regreased and no problems since. No idea if I dropped any shavings in the pot or not.

Good luck.

 

[dorkburger]

That is a big hole. Is it me or does it look to be at a different angle then the good hole?

 

[Guest]

Its too bad you couldnt find a larger spark plug and forgo the inserts.

 

[Burque73]

I scrapped a head that had a poorly attempted spark plug thread repair. The threaded insert type from the auto store did not work. Not to mention it was drilled out of square so the spark plug would not seal when tightened.

 

[04colyZQ8]

I bought a princess auto (Canada's version of harbor freight). It looks like a time sert knock off? It has a reamer that threads into a regular 14mm hole, then bored the hole, then cuts new threads! Has a solid steal insert, that's knurled at the top. And a I stall tool for the insert. I bought red locktite to seal, and help lock it in place.

 

[04colyZQ8]

Well I royally screwed up!!! Darn Heli coil tap hit the intake valve, You can zoom in and see a "rub" on the valve margin. You got to have the piston down a bit, and both valves close to being closed. I didn't realize this, and wish someone told me(( How bad is it to run like this? warp..valve due to heat transfer over time or detonation, due to the sort of sharp edge? This is minor its not on the sealing area. If it were a lawn mower I'd say don't worry about it. I don't have the time or money to rebuild the motor right now.

You cant just pull the head... jugs should come up too, then replace the jug gasket, might as well do rings.. might as well have the head resurfaced and vavlve seats cut, new vavles.... were does it freaking well end?????? I hate you bike!!

 

[04colyZQ8]

Here is the finished project, it worked perfectly minus the valve damage! Red lock tite in, and pilot tool seated steel insert. Returned crappy princess auto insert, bought quality heli coil kit. Looks great! I even taped a 1/4" I'd hose to a vacuum an cleaned out all the shavings, wasn't much, grease on the tap worked well! I'd do this in a heart beAt again. Just make sure the pistons down far enough and both valves are closed!

 

[04colyZQ8]

Finally its running good, better then it ever has! I found two intake boots leaking, to the carb, I need smaller band clamps? I stuck a zap strap between the band to make it tighter, and sealed it.

I used the motion pro tool to sync the carbs.. what a great tool! Took a bit the screws are next to impossible to tighten the lock nuts with out changing the adjustment, and what a ridicules spot for carb number 2 adjuster right under the throttle cable

Anyway, has so much torque, and idle is so smooth, no more backfire, no more popping, when backing off the throttle, and no more miss at wot, there is a slight hesitation, near 9000rpm, but nothing like before!

Thanks for all your help guys, the , major problem was cylinder #2 spark plug not sealing, that plug was soot black, the rest were tan!

Now if I could only seal the valve cover? still leaks, I give up! I tired making a gasket from gasket martial, and siliconing it, that leaked, I tired the oem gasket with silicone only around the rubber plugs, that leaked really badly! Now I tried no gasket at all, and loaded it with silicone back rtv, let it set up, then retorqued,let it cure for 20hrs, then rode it, still leaking!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! There are no words to describe hoe frustrated I am with leaking oil on this bike! I am ready to JB weld it together!!

 

[850 Combat]

I've done it without pulling the head.

 

[mvalenti]

I got one of these (android plug) dirt cheap... works awesome. Maybe attach a little vac hose to it and use it to search and suck the shavings... Good Luck!

https://www.amazon.com/Diameter-Waterproof-Endoscope-Borescope-Inspection/dp/B00N4L5N4A

I got mine from a app called geek, came from china in a few days and was under 10 bucks shipped...

 

[04colyZQ8]

I'm already done, but that's a really cool tool might buy it anyway