gs450s loses power badly

[badgti]

hi guys,

here's the situation, i just bought my gs450 from this guy who really didnt really do much to maintain it other than having regular oil changes, first day getting the bike i tested it and it ran great after warming up and had good power, the i had to transport it back to where i stay which is quite a distance , so i bolted it on the back of my friend's pickup and we brought it back, and only 2 things happened along the way was we stopped to fuel up the bike and the bike was exposed to the rain all the way back..once back we unloaded the bike and warmed it up and it became gutless, totally no power and i had to travel at 60kmh all the way back home, it just couldnt rev ..it was horrible

i brought it home and cleaned up the carbs and same problem, tried to bring it to my shop to do more work and it died suddenly halfway and couldnt start, next thing i did was change the plugs and ignition cables and it fired up again, but when it did i revved the hell outta it and it idles nice and when i brought it out for a run it had power, but 1st 2nd gear and it died suddenly again and couldnt start, battery weak maybe as i dint have this battery charged up properly or could it be something else? a friend of mine say that bikes with this type of displacement needs a fully charged battery.

ok..now i really dont know but there are some that say i need a new cdi which is super rare here, in fact most gs parts are rare..
any ideas guys,
sorry for making this so lenghty..

[mpencegs]

I am sure basscliff will be along to give you the official welcome but let me say hi.. I also own a 450 and love it.. If your worried about the battery or the charging system start with the stator papers on this site.

http://members.dslextreme.com/users/bikecliff/

http://members.dslextreme.com/users/storagecliff/images/stator_check.pdf

You really need to go through the site and the docs and understand whats happening..
I bet someone comes along who knows better then me.. I love this site for the poeple and the help.

[tom203]

So it ran OK prior to "being bolted to back of pickup truck (what does this mean???)" and having new gas put in and it got rained on? Any chance water got in fuel tank?

[pete]

First things first is to determine if it's a fueling issue or ignition/spark issue.

Have you checked to see if you have good spark on both plugs?

Are the plugs wet with fuel when it stalls?

Is there fuel in the float bowls when it stalls?

One thing with the 80 - 82 450's is that they seem susceptible to the ignitor failing if the charging system is over-charging (too high voltage), so it's also a good idea to get the charging system sorted ASAP as per the previous post.

Oh, yeah, these don't have a CDI, it's called an ignitor Technically it's transistorised ignition...

[badgti]

tom203,
i tried the bike around my friends place and it was good, and we bolted it up behind the truck to transport it back to where i stay which is 650km away, so while on transit back we stopped for fuel for the truck so i decided to fuel up the bike too since it was behind, and we were on our way back home an throughout the entire trip its was raining. when back home we unloaded the bike and it became very very very gutless..major power loss

pete,
i checked the plugs and they were all worn so i replaced them, didnt check the plugs when it stalled tho,but the old ones indicated it was running a severely rich mixture, poor ignition maybe cos the plug cables were worn out too.got them replaced too and the bike started up again and had power back but it ran only short of a 300m before it stalled again.thing is, could a poor charging system cause this cos tho my battery is new, i had the shop to charge it for only 30 mins..

[pete]

It could be either fueling or ignition...

If your ignitor is dying, it could be firing on one cylinder for example.

If it's fueling, then when it stalls one or both of your float bowls may be empty.

Has a fuel filter been installed between the fuel tap and carbs?

When it stalls, pop the fuel cap off and see if it will start.

The fuel tap may also be an issue if it is not flowing correctly.

Also, with cleaning carbs, these will likely need a soak to get the fuel varnish out of the passages and the O rings usually have deteriorated by now as well, so get a new set from www.cycleorings.com and that will make sure they're good as well.

[BassCliff]

Hi,

Have you gone through the maintenance lists in your "mega-welcome"? You need to properly address every item. You need to replace 30 year old rubber. You need to seal the air intake. You need to properly clean the carbs. You need to check and service the charging system. You need to adjust the valves. Etc, etc, etc. All of it has to be properly done in order to have a baseline to work from for further troubleshooting. Skipping steps and taking shortcuts will lead to frustration at best and be dangerous at worst.


Thank you for your indulgence,

BassCliff

[badgti]

Thanks BassCliff

Well..managed to sort out some issues with the bike and it started and idled nicely..went for a spin and it died suddenly and I had to push it bck home...
Tried to start it but felt as if starter haf no power so went to charge the battery and tried again and guess what...it couldn't turn over at first but after trying again...it turned over but with a huge metal "clunk" sound...and now it refuses to start...looks like its lost compression but ive yetto confirm...

[pete]

I'd be checking the valves and check the timing of the camshafts.

Check the camchain tensioner and make sure it's actually doing it's job.

I've heard of a few now that have been installed in the "locked" position and left that way so the tensioner is not actually tensioning anything.

[BassCliff]

Hi,

Thanks BassCliff

Well..managed to sort out some issues with the bike and it started and idled nicely..went for a spin and it died suddenly and I had to push it bck home...
Tried to start it but felt as if starter haf no power so went to charge the battery and tried again and guess what...it couldn't turn over at first but after trying again...it turned over but with a huge metal "clunk" sound...and now it refuses to start...looks like its lost compression but ive yetto confirm...

My first guess would be hydro lock. A failed petcock or valve seats have allowed fuel to fill a cylinder. It will eventually leak into your oil. Don't run the engine this way. Take the plugs out and spin the motor. You may see gasoline spewing out of the engine.

You must do all of the maintenance properly.


Thank you for your indulgence,

BassCliff

[badgti]

well took the engine apart and found why it locked itself up , seems the cam retainer on the exhaust cam was bad maybe due to lubrication issues, but it looked as if the previous owner knew about this, the cam retainer bolts were too
long and so he used a nut to offset the bolts length,and the timing chain came off due to a broken chain guide...ahh,,,theres lots more, even the pistons are not stock..ill try to get some pics later

anyway,
is there any way or anyone who sells complete cyl head assy for the 450? i need a chain tensioner and an new chain guide and stock pistons...also i need new cams the exhaust cam is in bad shape

[pete]

All you can do really is keep an eye out on eBay... bugger!

[Red]

gs450s

Hi m8,
What colour are your plugs and do you have good compression.
Start with the basics;
- Good compression
- Good spark / colour
- Valve timing good
- petcock working ok, diapraghm good condition
- Carbs balanced
- Carbs jetted with standard spec sizes
- Air box standard spec with correct lightly oiled filter

It's very important the basics are correct otherwise you could keep going around in circles.

Red