GS450 Rebuild

[Guest]

I don't think it really matter which way up the gasket goes.

As for those bolts, I don't have them on my 450... and I can't see them on the fiche... hmmmm...

I've assumed that the extra flange on the flame ring was to deal with the heat of the exhaust valve/port next to it. IOW H is for the side toward the head, thus UP. The bolts look to be plugging the passageway that goes from the head stud to the cam bearing; maybe somebody drilled the plug out to clean it and plugged it with a bolt.?? As long as it doesn't leak?.

 

[sam000lee]

Thanks for the gasket orientation info. I got the head on, but when I went to put in spark plugs I discovered that one of them has been cross threaded at the top and wouldn't screw in easily:

So I bought one of these thread chasers from the auto store:

I'm worried that I'm messing/going to mess the threads up even more. I thought that it would straighten out the top few threads and then thread easily into the remaining good threads but I can feel resistance and don't want to mess up those threads. The guy at the store told me that was normal since it was cutting new threads but I was under the impression that it would just follow the existing ones once the first few were sorted out. Here's some pictures after turning the chaser a couple of times:

Some advice from someone whose done this before would be great.

 

[tkent02]

My advice would be to do it with the head removed. Chunks of aluminum will get in there. Second best advice, put globs of grease on the tap to catch some of the swarf.

 

[dantodd]

Assuming the head is removed try going in from the m inside where the threads seem better. That will align the chaser/tap with the existing, good threads.

 

[tkent02]

Yes if the tap is long enough, but with care it will go straight from the outside too. Just go easy and make sure it isn't crossed up again.

 

[sam000lee]

Should the chaser be able to thread into a non-crossed hole? It seems like it is ever so slightly bigger than the existing one in order to cut threads but doesn't thread into the good plug holes on my extra head unless I were to put the socket on it and apply force.

I'm obviously using the 14mm end of the chaser in the picture but it seems like its the tiniest bit too big.

 

[dantodd]

Should the chaser be able to thread into a non-crossed hole? It seems like it is ever so slightly bigger than the existing one in order to cut threads but doesn't thread into the good plug holes on my extra head unless I were to put the socket on it and apply force.

I'm obviously using the 14mm end of the chaser in the picture but it seems like its the tiniest bit too big.

I've never used a chaser, just taps. If it is properly lubed it should move like.... um well, it should not feel like it is having any resisrance.

 

[sam000lee]

Then is that 14mm chaser the wrong size? I have 3 cylinder heads with 5 good spark plug holes and it doesn't thread into any of them without me putting the socket on.

 

[Guest]

Perhaps it's 14mm but the wrong thread pitch? Compare the threads with what's on the plug and see if they look finer or coarser...

 

[sam000lee]

When I held it against the plug threads they matched up well. Package says it's 1.25 pitch so should be the same. I might be second guessing myself, but I expected that I would be able to hand tighten it into a non-damaged hole when it seems to want some force.
Anybody whose ever used a chaser as opposed to a tap comment on how easy it should be going in?

After reading some other threads I'm also considering trying one of these chasers that goes inside the hole and then backs out: http://www.amazon.com/Powerbuilt-64...ug back tap&qid=1464718203&ref_=sr_1_1&sr=8-1

 

[Guest]

Which plugs does it use. The common B8ES plugs are 14mm x 1.25 pitch.

 

[sam000lee]

Yup the B8ES

 

[Guest]

Sounds like you have the right tool then. You said you had a spare head with one damaged thread? Try cleaning the other thread in that head. Lubricate the tap/chaser with a little oil, turn it in a little, making sure it's not cross-threaded, then back it off a touch, turn it a little further, back off, etc etc. If you think the tap is cutting a lot of swarf, remove it, clean it, re-oil it. Once the thread is cleared, try a plug and see how it fits. If it goes in cleanly and seals, you know you are ok to work on your good head.

 

[sam000lee]

Got it sorted out with the chaser. I was a little bit skeptical but just needed to actually put a little bit of force into it. I did it with the head on, a greasy rag in the piston and bunch of grease on the chaser taking it out every couple of turns to clean and regrease. The plug is a little looser than originally when you're threading it in but it tightens up nicely. Thanks everyone!

Here it is:

Now I have to figure out why my L/R cylinders are acting differently. I have another thread here for that issue, though.

 

[dantodd]

Glad it worked out for you.

 

[sam000lee]

Back on the road for the first time this year! I spent about 5 hours yesterday getting the carbs right with my setup. I'm running UNI Pods and EMGO shorty mufflers. I have 140 main jets, 40 pilot jets and shimmed the needle by `1 washers worth'. It's definitely running a little rich.

I went for a little ride, and the engine cut out. It wouldn't start again at all and for some reason I was worried that maybe I had set the timing incorrectly or something. I ended up walking the bike home about a mile. What it ended up being was that spade on my coil relay coming from the battery vibrated off. I checked the timing anyway because I'm paranoid... everything checked out. Whew.

Here's the bike taking a rest on our walk:

Here's my mockup for my new LHS side cover:

Here's how I secured the exhaust:

Just have a few things to clean up still and I have a week until I start my new job so I'm going to be riding as much as possible until then!

 

[m-gaardbo]

Wow this is a cool bike!
I'm going to see a Gs400 tomorrow, might be my first bike!
How is the sound with your new mufflers? They are really cool!

 

[sam000lee]

Thanks! They sound good, it's deeper than stock and a little louder, but I re-wrapped them in muffler packing today which quieted it down a little. It's crazy the junk that came in the mufflers, this is it after about 80 miles:

 

[sam000lee]

Spark Plug Reading

Spark Plug Reading

I did a couple hundred miles going out to Western MA this weekend. I'm pretty happy with how the bike held up and how it feels although I am getting a little bit of popping on decel. A couple of things I would appreciate input on:
When I got back I checked my plugs (B8ES). The right one looks okay to me:

When I went to pull the left plug, I noticed it was a little loose (I few posts back in this thread I chased the plug hole so) so I need to remember to make sure that one's snug every time from now on... but the tang looks like it's been bent inwards a little bit:

What would cause this? I'm guessing some kind of mechanical interference but don't really see how that could happen without also having bigger problems. I'll throw a fresh pair in today to see what happens.

Another thing I have noticed is that, once warm, the bike will occasionally miss at idle. It's normally right when I come to a full stop at a light - there is a little thud noise and a slight jolt and the idle drops for a second but then picks right back up and acts just normal. This happened in my old engine as well and I never really worried about it so it makes me thing that it is not what bent the spark plug tang. What would case this? Should I be worrying about it?

 

[Guest]

Do you have children? They'll sometimes drop something and then put it back where it was, hoping you didn't notice. Looks like somebody dropped it. I always reflexively look at the tip just before screwing in a plug - a good habit.

My 450 does the same little hiccup once in a while if I come to a halt after a while, as if the idle circuit had run dry from lack of activity, like after a long downhill. There might be a cure in the pilot screw setting, but then you may just get other problems in trade.