Project Soon To Start Over...SMH

[fieroracer87]

well last july my bike i had spent so much time putting together destroyed itself. Carbs were tuned but it ran rich and melted the spark plugs in two of the cylinders. I'm getting ready to get back to working on it but i want to upgrade a few things and need some feedback.

1.What sportbike front forks will fit/ would be recommended to replace the stock units.

2. is there another rear swing arm that i could bolt in as well that would make it easier for me to convert to a monoshock setup. if not I would still like to know what bolts in because finding brakes for these bikes is getting harder and i figure im better just converting over.

3. was there any know engine swaps for this bike..(79 GS550LN) if so that would save me the headache of rebuilding and sourcing another parts bike. this junkyard i go to has alot of 80's and up sportbike stuff


Thanks to all that lend me a hand in advance. I Love the bike and would hate to get rid of it.

[mike_of_bbg]

Can't answer 1 and 2, and can't tell you about any other model engines that might fit, but any 77-82 8-valve GS550 motor should bolt right in. If you get an 80-82 you won't have a kick starter any more and will have to retro-fit your old ignition or go Dyna if you haven't already (or fit the newer electrical system with the ignitor to your bike).

[fieroracer87]

thanks...i've just sent out a parts request for 80-82 engine and carbs...i should be hearing back on that in a few minutes. now all i need now is some more information on forks/and swingarms

thanks again mike

[hikermikem]

Carbs were tuned but it ran rich and melted the spark plugs in two of the cylinders.

That sounds like they were running lean...

[old_chopper]

I agree with Hikermikem, rich shouldn't melt the plugs. If the electrodes went away and you were left with a hole in the piston the engine was running too lean. Might have also been caused by too much timing or too hot a plug but my bet would be lean. Not much help now but something to remember. A mentor once said an engine makes the most power as the tops of the pistons are melting away seconds before it blows up. Been there and he was right.

[fieroracer87]

well when it happened everything seemed normal...then i lost power. choked the carbs for a second and back to full open and it ran normal again. well i just got my email back about the 80-82 gs550 engine and they can have me one running for 400dollars and another 150 for carbs. and they guarantee all their stuff. so im considering running this route. I do have another question.

4.will i still be able to use my exhaust with this newer engine?

[fieroracer87]

I plan this to be a long term project. When this bike broke down in the beginning of the summer I didn't want to miss out on the rest of the riding season so I went out and bought a brand new 09 250 Ninja. which is perfect because it now gives me time to do the bike the way that it should have been done. the only reason i wanna update the forks/swingarm is so i can easily upgrade the brakes since its been hard for me to locate rotors in good condition unless there is something i can do along those lines that i have not heard about.

[doctorgonzo]

Unless they are freshly cleaned and ready to bolt on without touching them, that's a smidge high for carbs. A rack of "everything is there, and in in good shape just need cleaning and the o-rings replaced" CV carbs more in the $75 to $100 range in the current parts price environment. Does the 550 use 32's or 34's?

[fieroracer87]

they told me that the engine is from a 81 550 so i have to find out which carbs were used on the 550 that year...maybe basscliff knows. im gonna go thru my book and see. i might be able to get away with using my carbs that i currently and save some coin.

[doctorgonzo]

they told me that the engine is from a 81 550 so i have to find out which carbs were used on the 550 that year...maybe basscliff knows. im gonna go thru my book and see. i might be able to get away with using my carbs that i currently and save some coin.

79 will be VM (I think) and 81 will be CV.

[mike_of_bbg]

Yeah, you have VM and the 81 has CV. I think I read that the VMs will bolt on to the head OK though; might want to see if anyone else who has more experience with that will chime in. Not sure if your airbox would fit the CVs or not (kinda doubt it) so that could be an issue that would make you want to stick with VMs more than just coin. Most in the know seem to prefer the VM carbs anyway.

Though, you'll probably want to fully clean your VMs and dial 'em in before re-using them. No need to crisp another valve!

[fieroracer87]

yeah my 79 has the VM22SS's and the 81 has BS32SS's im just wondering if i could possible use the ones i have or should i just shell out the extra money to get the ones that come with the engine and dip them and rebuild.

[fieroracer87]

Yeah, you have VM and the 81 has CV. I think I read that the VMs will bolt on to the head OK though; might want to see if anyone else who has more experience with that will chime in. Not sure if your airbox would fit the CVs or not (kinda doubt it) so that could be an issue that would make you want to stick with VMs more than just coin. Most in the know seem to prefer the VM carbs anyway.

Though, you'll probably want to fully clean your VMs and dial 'em in before re-using them. No need to crisp another valve!

yeah i really don't wanna go thru another engine. everything has to be on the money this time. if i go with the cv's that would help me clean up some space under my seat since i would be running pod's...i like my vm's because they are a simple rebuild.

and since i don't remember putting up a picture of the bike in question i might as well...

[mike_of_bbg]

Not that I've any personal experience with it, but every thread I've read here on the subject says that VMs are much easier to tune for pods than CVs.

[Steve]

...i like my vm's because they are a simple rebuild.

Please tell me how the VMs are any easier to rebuild than a BS (CV).

Maybe I have just done so many of the BSs, I think that they are rather easy.






By the way ... NICE BIKE!!

Did you do the work or did you get it that way?

.