I'm back and here to stay

[kawonda750]

I have sold my Kawasaki triples and have now bought, and plan to keep, a 1974 GT550.
I am doing a complete rebuild on the engine and have purchased a set of IMD +1.0 mm pistons. Stated piston to cylinder clearance is listed as 0.0015 inches. My machinist says this seems too tight. Has anyone any experience with these pistons and, is this clearance correct? It is the iron sleeved engine.
Also, greetings from Canada.

Looking forward to this bike. Thanks

[badgereng]

I used +0.5mm IMD pistons in my GT380. The workshop that did the rebore used the IMD recommendations of piston dia + 1.5 thou for the two outer pistons BUT made the centre bore an additional half thou bigger.
They’d done a million more rebores than I had and was happy to follow their guidance.
No issues to report.

How this helps

[Alan H]

IMD did the +.5 mm rebore for my 550J a couple of years ago, but I never measured the bores afterwards. However it starts on the button, 2000 miles on and at a steady 4000rpm does over 60mpg (imperial gallons) without vibration or issues.
A bit less mpg with normal running, but not spanked - that's what the 550A is for!

[kawonda750]

Thank you guys. I guess I am just being too cautious. I will go with the recommended clearance. The Suzuki manual says 1.8 thou so very close to what IMD says.

[kawonda750]

Now, my biggest roadblock is exhaust baffles. The pipes are in great shape but somewhere down the line the baffles were removed. I have contacted the seller but he doesn't know where they are. Ebay has them but for a total of about $1200. I want the bike to be quiet but am not excited about spending that kind of money either.

Is there an alternative baffle ? Or, does anyone have a set they don't need? Or, is there an expansion chamber that is relatively quiet?

[stevewharton]

Hello (name?) In Canada.

Here in the UK a company called Delkevic sells new repro baffles for a GT750 kettle for around £25 to £30 each, I've bought a set and they are spot on.
Not sure about a GT550 but I think they're probably the same, well worth checking out.

Cheers Steve.

[kawonda750]

I have had a few Delkevic pipes on bikes Steve. I will check with them. Part numbers are different.
Thanks
Dave

[stevewharton]

Hi Dave,

I've just looked at the Delkevic website and the baffles for a GT750 cost £29.99 each, I've asked the question whether they'll fit a GT550 and they'll let me know.
I do seem to remember being told a while back that they're the same, but I'll let you know asap.
A big saving for you if they do

Cheers Steve.

[kawonda750]

Thanks Steve. That would be great! There are different part numbers but maybe only a small difference that could be fixed somehow.

Otherwise, I have found universal 2 stroke baffles that may work too. I will try to get dimensions if your query doesn't work out. Your help is much appreciated.

[kawonda750]

I managed to get the big baffles on ebay. I bought 2 bad pipes fairly cheaply and the seller took out the baffles and shipped them separately. Sure beats $249 each. Now it's just a matter of finding someone else willing to remove the smaller baffles.

The cylinders are at the machine shop being bored for IMD +1.0 mm pistons . I am waiting on one final crank seal so I can send the crank out to be done. In the meantime , there is a lot of cleaning and scraping to do. It looks so good in the pics until I get under it and see splooge and old greasy dirt.