GT550A top end woes

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Evans Ward
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Suzuki 2-Strokes: 76 GT750, 72 H2 750, 84 RZ350, 67 YR1, 82 MB5
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Re: GT550A top end woes

Post by Evans Ward »

The 72 Kawasaki H2 is my first love and I’ve had it in a modified state with chrome original TNT spannies but back to stock now. It only has a couple of minor mods from stock now with a Kawasaki EX500D front brake caliper and a windowed repop oil pump cover to be able to see the oil pump cam move. I have the original higher leaded handlebars on it along with the centerstand and stock exhaust right now. I’ve logged more miles overall on 72 H2s than any other 2 stroke I’ve ever owned.
1976 Suzuki GT750 (Maui Blue), 1972 Kawasaki H2 750 Mach IV (Candytone Blue), 1984 Yamaha RZ350 (KRR- Yellow/ Black).
vulcanman
On the street
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Joined: Sun Mar 07, 2021 2:32 pm
Country: United Kingdom
Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

My mates H2 has Higgs expansions on at mo but he does have a good std set of pipes .that aside pretty much std .he sold a 74 RD250B to my mate last summer which was in need of tlc.all complete and std .last used to go to Spa for a bikers classic 5 years ago .it is identical to the bike the fella who bought had in 75 .his 1st bigger bike .he has totally restored her to as new and has 7 miles after 1st run out this week .ive never had a kwak stroker only Suzukis .had a 380 and a 750 both long gone.the 550 suits my age .60 now and not interested in high speed.happuer making smoke and doing 50 or 60 mph.im off to kip.nice to talk mate
vulcanman
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Good news .piston kits and gaskets arrived this morn and platers rang to say barrels be back on Mon.i have no idea how to add photos on this site but be happy to if i can work it out .🤣
vulcanman
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Joined: Sun Mar 07, 2021 2:32 pm
Country: United Kingdom
Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Afternoon Alan ,well the 550 is up and running.transformed.quiet motor .ran 2lrts of pre mix for 5 mins then drained .while on pre mix took all the oil lines off one at a time and pump working well .head i torqued to 29lb and will check again at 100 miles .i set tickover to 1500 .after 1st start up and an hour break went round all fixings before putting seat and panels on .been out for a steady 10 mile run .not using 5th gear as dont want to labour the engine .new air filters in and i found some air filter oil to use .bike transformed and a joy to ride.smoked a lot on 1st start as lots of lube on all internals .once out on ride she smoked gently but not excessively .im sure once run in and i can rev her out she will smoke as before .bit nervous of any engine noises as this has been expensive .
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Alan H
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Suzuki 2-Strokes: 2 x GT550s GT750B, GS750B
Location: The Republic of South Yorkshire

Re: GT550A top end woes

Post by Alan H »

Use 5th and be happy! 4000rpm max for the 1st 100 miles- should be good for 55mph - then add 500rpm each 50 miles after that if you're cautious.
Personally, my 550A got 4000 for the 1st 50 and 1000 each 50 after. When I've changed the clutch plates & springs it'll get some more!! Really it's only the bores that need running in, bearings don't, and my A has SCEM barrels and 'iron' rings..
Think of how stupid the average person is, then realise that half of them are more stupid than that.
vulcanman
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Well she lasted 8 miles .just will not start .got fuel ,air ,sparks .nowt .just wont go on kick or button .im my wits end now .
vulcanman
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Joined: Sun Mar 07, 2021 2:32 pm
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Have tried a hot set of fresh plugs .still wont catch.battery on charge til Mon now .got a spare thats on charge too .try again Mon .this one is testing me !
vulcanman
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Hi Alan ,well still no go.got new plugs ,good sparks ,fuel and oil getting through,running out of ideas.any clues be appreciated .
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Alan H
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Suzuki 2-Strokes: 2 x GT550s GT750B, GS750B
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Re: GT550A top end woes

Post by Alan H »

Hmmmm. If you've got all the necessaries there, it should go.
As it's actually run, there shouldn't be too much wrong, so I'd suggest that you take off the air filter caps and remove the air filters, then squirt a bit of easy start into each carb to see if that helps when you spin it over.
Hopefully the new plugs are genuine and not cheap chinese copies.....
Starting the 550 always needs choke from cold. Full choke and a 'whiff' of throttle, then spin the engine and knock the choke off slightly as it fires. I also have an inline fuel filter in the line between carbs and tap on my A.
If the easy start method doesn't work, it looks like check timing and carb float bowls to see what's in there. Very strange.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
vulcanman
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Joined: Sun Mar 07, 2021 2:32 pm
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Hi Alan,yes plugs are genuine .however just incase have put another set in.1st start of day always needs choke.after lunch i be trying again and yes will remove air box ends and have a squirt! 🤞
vulcanman
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Hi Alan,took air filters out and she started 3 rd kick .left her ticking over for 3/4 mins .filters nack in .now starts on button easy .hope to be out on her Wed and get some miles in .thank you for all of your tips .
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Alan H
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Suzuki 2-Strokes: 2 x GT550s GT750B, GS750B
Location: The Republic of South Yorkshire

Re: GT550A top end woes

Post by Alan H »

Very strange. Wonder if the plugs were duds then?
Wonder if the filter on the fuel tap - inside the tank is partially blocked, or even the air vent in the tank cap. Both will cause eventual fuel starvation to the carbs.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
vulcanman
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Joined: Sun Mar 07, 2021 2:32 pm
Country: United Kingdom
Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Well i be out shortly and i find out if fuel starvation is an issue.plugs could have been duds but id be surprised if all 3 were .i let you know how i get on.
vulcanman
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Joined: Sun Mar 07, 2021 2:32 pm
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Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

Hi Alan ,65 miles done .spot .not missed a beat .going to check head in morn then leave her be for 200 odd miles .thank you for all your guidance and clues where to go .looking forward to riding her now much more .
vulcanman
On the street
Posts: 44
Joined: Sun Mar 07, 2021 2:32 pm
Country: United Kingdom
Suzuki 2-Strokes: GT550A 1976

Re: GT550A top end woes

Post by vulcanman »

By the way ive tried to add photos but says file is too large .
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