Fitting OEM Exhaust to GS1000G

[Johno]

Thanks to Daniel and the GS Resources forum I now have accumulated the pieces of an original exhaust system for my 1981 GS1000G.

I still have some rust removal work and ordering gaskets but should be ready to go in a few weeks time.

I'm currently using Reducteur H-72 to ensure that the current exhaust studs are removed safely when the time comes to take off the old O'Brien 4 into 1 system.

I'm looking for advice on the best way to assemble and fit the standard system.

I'll replace the gaskets where headers 2 and 3 fit into the mufflers on each side.

Is there a gasket where 2 and 3 connect at the cross over?

What is the preferred sequence to fit the headers and mufflers to the bike?

The Standard system components are reasonably heavy and need to be aligned with the exhaust ports and rear mounting bolts.

Any suggestions from your experience would be appreciated.

[Johno]

Fitting OEM Exhaust system

I've had to bump my own post as there have been no replies. I am proposing to fit the header to No. 1 cylinder first loosely bolting the muffler to the frame. I'll loose fit the header to No. 2 and continue to 3 and then four.

I expect that there will be a need to wiggle each additional part so that they interconnect for a secure fit without leaks. Once it is together I will progressively tighten connections so that each of the four headers and connections maintain an even tight fit.

Any thoughts?

[azr]

Geez, what's up with us. I guess everyone is out riding. I've been putting my exhaust on/off on my 80' 1000G. Like you mention, I put the headers in loosely with the two outer clamps loose as well (on #1 & 4) so I can get the cross over together. This whole time it really helps if someone can be holding up the mufflers, if you don't have help support them with something. It really helps to line up the headers properly. Make sure you bolt in the headers evenly across all four to avoid the bolts from stripping the aluminum. For the two inner headers that have the 'flanges' you can put them on the header before mounting and put a couple of small pieces of tape on them to hold them in place, works like a charm. Once the headers are bolted on tight you can tighten up the clamps for #1 & #4 headers (the ones half way back near the side stand and brake pedal) The last bolts to tighten up are the mufflers. Make sure you use some Never Seize or similar on all your bolts. If you really want to do a smart upgrade you can swap out the header bolts for threaded inserts (I think that's the wrong term) and use a nut instead of a bolt, it really saves the head and you never have to worry about snapping an exhaust bolt . There is no gasket for the crossover. It's always helpful to wrap some of the frame up front with a towel or something to prevent the paint being chipped, especially that cross pipe near the head. This is sure going to be a big change for the bike and will look great.

[Johno]

Thanks AZR, good advice and I think you have covered all aspects of the process.

It will be turning back the clock 30 years for this bike when the 4 into 1 comes off.

I'll start the derusting process this weekend and order the additional hardware for the build.

Photos to follow.

[Johno]

OEM Exhaust gaskets

I dropped into my local Suzuki dealer this morning to see if I could order OEM exhaust gaskets to use on the exhaust rebuild.

I was surprised to find that they had the metal ring gaskets required for each exhaust port were in stock on the shelf.

The four semi circular spacer/gaskets for the middle two cyclinders are on order and should be in early next week.



A friendly reception from the spare parts guy who appreciates old jap classics.

Maybe the competition from on line suppliers has prompted an attempt to provide friendly competitive service.

[Agemax]

having someone help you will make life a whole lot easier. one supporting the exhaust while the other lines it up and catches all the bolts.
get it all loosely fitted before you start tightening anything up

[Steve]

Don't forget to check the jetting in the carbs. IF they were jetted for the pipe, you will need to re-install stock jets.

.

[Johno]

Don't forget to check the jetting in the carbs. IF they were jetted for the pipe, you will need to re-install stock jets.

.

I fitted the Australian manufactured O'Brien pipe in 1983 when the original pipes rusted out due to short runs to the shops.

I didn't make any jetting changes at the time.

The change back will be an interesting journey.

I can't believe how much heavier the OEM system is than the 4 into 1.

[Steve]

I can't believe how much heavier the OEM system is than the 4 into 1.

I have read many dyno reports that showed only modest improvements with a 4-into-1 system, and that has led me to believe that most of the performance improvement is probably due to less weight, rather than more power.

.

[Johno]

I have read many dyno reports that showed only modest improvements with a 4-into-1 system, and that has led me to believe that most of the performance improvement is probably due to less weight, rather than more power.

.

The 4 into 1 was a cheap option for replacement at the time.

Additional performance was not the motivator. The psychological driver was a louder deeper exhaust which created the feeling of more power and aggression. Remember I was a male in my twenties.

The bike in standard form had more power than I would ever be able to handle. It was great to be able to unleash 6,000rpm + occasionally.

It was like riding a gentle giant which you knew could be unleashed to make the point if required and then go back to the docile sports tourer.

[Johno]

Four into one removed

Time to bump this thread.

I've had the OEM exhaust and hardware ready to go for some time.

As the GS1000G is my only rider I've been waiting for a time to take off the 4 into 1 and fit the OEM exhaust system.

It was 36 degree Celsius here in Sydney today that is near 97F so I spent some time in the garage.

I sprayed the studs with Reducteur H-72 and worked each one slowly.





All the studs except one moved fairly easily. One on No. 4 was stiff and I took it very slowly and used lots of the rust penetrant.

Here is the bike with the O'Brien pipe fitted.



I was very careful not to snap a stud - it is easily done - don't ask me how I know.



With the exhaust removed I can clean up the engine before fitting the OEM exhaust.

[Dogma]

Interesting shocks.

Advice on this thread so far has been great. My feet are big enough to hold the muffler up while fitting the header into the head. I've also done it by holding the muffler in one hand and the header in the other. Once the pipe is seated in the head, move over to the muffler end of the project and get a bolt in loosely. Or even just slide a round-shafted screwdriver through to hold it while you get a rest from wrestling the beast. Mind the threads, of course.

I assemble 2+3 together loosely before installing. Once everything is hung, I like to start snugging things up at the muffler end. The flanges tend to straighten things up. Make sure the side stand and center stand stow without rubbing the pipes before tightening everything up.

[Johno]

Interesting shocks.

Dogma,

The shocks are French - Fournales. Air over oil. Fournales made shocks for the Concorde.

Thanks for your suggestions. I'll loosely fit the centre headers and then add one and four with the mufflers.

I'll probably do it Thursday or Friday ready for a weekend run.

[Johno]

Exhaust bolts

the exhaust bolts are probably original and I would like to replace them with new. One appears to have a damaged thread as it was tight to undoe. The others appear OK.

Due to the Christmas holidays most engineering suppliers are closed until 6January. I will ring a couple tomorrow but I expect they will be closed. The big hardware chain is open again tomorrow.

Any suggestions on how to clean up the threads?

I gave them asquirt of WD40 this morning hoping it will flush out any dirt.

[Johno]

Rethreading chasers

I have successfully used a spark plug chaser to clean up a spark plug thread.

As well as replacing my exhaust header bolts I would like to clean up the threads.

Has anyone used this product?

http://www.amazon.com/Mstc-RC7-Metric-Rethreading-Chasers/dp/B000AEX8DW/ref=pd_sim_sbs_indust_4#productDetails