Buying a GT750
Ok, so you want to own a Suzuki GT 750, or perhaps you’ve just acquired one and want to jump in and start work. Well, the first thing to do is stop and think! They are very very desirable, but like any piece of machinery they have important, individual points to watch out for before spending money. All of our members would strongly recommend that anyone contemplating buying and/or restoring a Suzuki GT 750 who does not know this machine inside out (literally) sign up now for membership of The Kettle Club and seek the clubs knowledge and assistance before parting with any (more?) hard earned cash, other than the club membership fees of course!
It is worth repeating:
STOP -THINK- RESEARCH, JOIN BEFORE BUYING ANYTHING.
What model is it? (See model changes under the bike section for differences.)
Buying any model as boxes of bits and restoring a machine can cost you twice what you could pay for a fully restored running machine. Expect to be asked to pay between £2,000 to £3,500, (yes three thousand five hundred pounds!) for a better than "showroom new" early 'J' or 'K' model fully restored inside and out. After all there is nothing wrong in asking is there? Bear in mind the seller has probably spent more than this and hundreds of hours of Tender Love & Care locating parts and restoring it.
If you are not after that degree of excellence £1250 to £1750 should buy a very presentable (later model) and reliable machine if you take care. If you take your time and look examples can still come up between £600- £1000 due to seller’s circumstances.
Incomplete project rebuilds can give good results, if the seller has bottled out after spending lots of cash on bits over a long period of time. Always start by asking the history. I don't think you will find a "one elderly lady owner with 10k on the clock, kept it in her front room" examples, but a quick external paint job and polish can hide big problems internally so history is a must.
So, does you’re prospective purchase have merit? If you do not know, get onto the members help line (you did join before going out to buy didn't you?) and see if anyone local to you can assist, that's what they volunteered for, to help! If you think you do know then check the following. Some are a bit obvious but may be missed through those rose tinted specs you may not be aware you are wearing as you fondle all that hot cash! “What about the crankshaft oil seals.” ? This is one of the most frequently asked questions and one of the most important (In some cases the most costly problems). If the bike has been standing for a long period of time the seal(s) may have dried, become brittle and stuck to the crankshaft, turn the engine over and oops failed seal(s). Depending upon which seal(s) have failed visible symptoms may or may not be present. An easy way to check this is to remove the oil pump front cover, which is retained by two screws, one top left & one bottom right, on the right-hand side of the engine. (To the rear of the top half of the crankcase.) Look for signs of gearbox oil around & in the "well", the small collection area in front of the oil pump. At the bottom of this "well" (at the front as you look at it) there is a 6mm hole, bottom left. This hole should be free of any foreign objects such as; small round bits of wood, putty, filler or anything else that the present owner may tell you should be there. In all cases it should not have a screw or bolt of any description fitted in it, The hole is there for the purpose of draining any fluids that has accumulated here & on top of the crankcase. check this area first. I have found that sometimes a very small amount of oil combined with small bits of grit are usually road debris that has accumulated there over a long period of time. Clean around this area leave the cover off.
If the bike is running ok, & if possible, take the bike for a hard blast. (Of course when riding the bike from cold it is not a good idea to thrash it) to see if any oil appears in the well, or if any has dribbled out of this hole. If so, then one of the crankshaft oil seals is likely to be failing or the gearbox oil level too high. Point this out to the seller as you could reduce the selling price by hundreds of pounds. After purchasing, keep an eye on the points above for a few weeks if you followed the advise you should not have any problems. Will the oil pump still work? The oil pump should still work fine after standing for a period of time. However, thoroughly check the oil feed pipe from the 2-stroke oil tank to the 2-stroke pump for signs of perishing or cracks. Also, slip the pipe off of the pump to see if any 2-stroke oil is flowing through it. After purchasing. It would be a good idea to replace the 2-stroke oil with new as you will not know what sort of oil has been used. This need only be done after the engine is found to be running ok. You could bleed the pump with an oilcan filled with the 2-stroke oil of you’re choice and obviously of the same type as in the 2-stroke oil tank. When replacing the 2-stroke oil decide which type of oil you want. You can use either vegetable, mineral, semi-synthetic or fully synthetic. Caution should be used here and a note made that once you have selected the type of oil you want, continue with that type. If you wish to change the type of 2-stroke oil at a later date ensure that you clean and flush through the 2-stroke oil tank, the pump and the oil lines to the engine. It is not a good idea to mix any of these oils. “Will the fuel be OK”? If the bike has been standing for an extended period of time, (three months) then probably not, it is recommended to replace the fuel. Ask the seller if he has new fuel to put in the tank before trying to start the bike, if not then take some with you. After purchasing. A good idea is to remove the tank & fuel tap. Flush the tank with new fuel to remove any fragments of old paint or rust that may have accumulated in the bottom of the fuel tank. At this point it would be a good idea to clean the internals of the fuel tap/cock. This should be done before commencing any cleaning of the carburettors. The carburettors should also be OK, if they are still fitted to the bike? But if they have the same old petrol in them as in the tank then the bike may not start very well or at all. If this is the case ask the seller to drain the carbs and refill with the new fuel. After purchasing. They can be drained and modestly cleaned whilst still fitted to the barrels and air filter. By removing the tops of the carburettors you can then remove the diaphragms & slides. Remove the drain plugs and spray a carburettor cleaner (available in most auto / motorcycle accessory shops) down through the inner body of the carburettors up through the drain holes. If cleaning the carburettors whilst still fitted to the bike ensure adequate ventilation & protection of surrounding area e.g.. the top half of the crankcase, paint-work on the bike, e.g.. the frame with absorbent material such as rags/cloth It would be better to remove the carburettors and clean them if necessary. If you decide to clean and dismantle them yourself ensure that you put the float bowls back on the carburettor that they came off of. Beware! If the carburettors have not been removed for sometime, the rubber mountings from the carburettors to air box & barrels may have hardened. If this is the case, take my word for it, they will be difficult to put back on.
Exhausts. Although you may think two strokes are too oily to rust from the inside on Kettles that is what happens. Check for signs of scrape damage to front underside of outer pipes where the flat area is. Check the baffles look ok. Ask when they last came out for a clean. New standard exhausts are now as rare as rocking horse teeth (? you know what I mean) and a good re-chrome can cost up to £600. Some presentable sets do come up occasionally in the club newsletter but you have to be quick.
If you cannot take the machine for a run, get on the pillion, insist on it. It should start from the electric start no problems, perhaps a little choke after a minute on prime if it has not run for a while. Expect any smoke to clear from exhaust after a mile or so. (when stopped oil in crank case drains to the bottom and is injected into the inlet on next start up). Good sign is smoke from centre pot (the two smaller exhausts) and very little visible from outers. Two up it should pull cleanly away but if not done properly may seem to bog down.
Engine. Look for signs of the bodger. Damaged screw heads, rounded nuts and bolt heads, missing washers, mismatched screw sets etc. Expect the same quality of work inside the engine as outside. If you have any intention of doing an engine strip down see if you can find out when was the last time the barrels came off. They often seize on their studs and you have a battle on your hands. Look for signs of past battle damage at the base of the barrels and hammer damage under exhaust ports.
Exhaust clamp bolts are often over tightened to stop exhaust blowing and strip threads in the barrels. A few common "faults" occur that can be checked for.
If chain has lost its spring link in the past the chain can jam up around the drive sprocket and damage outer crankcase and neutral/gear indicator switch housing. Remove gear lever and cover to check.
Check gearbox oil, any milkiness is probably a sign of water pump seal failure. Check water level and signs of oily water. Check also the small drain outlet on the edge of the water pump cover on the underside of the engine/gearbox. This can weep oil or water or a mixture of both if the water pump seal(s) are iffy.
The clutch. The clutch basket has a steel band around the outer edge. This often splits, comes away from the basket and is chewed up by the primary gears with steel and bits of aluminium going everywhere inside. Worst case is enough band bits jam the primary drive gears to made the engine appear seized.
Originality. Unless you are a stickler for originality there a few add ons we think improve the machine and are worth looking for. Electronic ignition is a big bonus. If a Newtronic system is fitted that's a plus, some prefer the design of the Boyer Kawasaki unit. The Boyer unit fires all three pots every 120 degrees and therefore timing is not individually adjustable for each cylinder. The Newtronic system replicates the original points set up, electronically, each pot firing separately every 360 degrees and the timing of each pot is adjustable separately. Solid state rectifier/regulator, again the Newtronic unit has given good service to me. Sealed beam halogen headlight good mod, fork brace is another. Allspeed 3 into 3 pipes are not available new any longer and do improve performance if jetted correctly. There are some sets around but they are valued by their owners, watch for adds in the club newsletter. The Piper 3 into one has its followers. Improving bottom end performance but some say chokes the top end. Finally do not forget to ask for any spare parts he/she may have. Even if you do not need them you may recoup some money by selling them through the club newsletter the "Flexi Flier" and help another member get another Kettle on the road. Why not copy and paste the above information and print it off and take it with you to use as check list when you go to look at your dream bike.
Please Note. The use of a work shop manual is strongly recommended in all cases. The opinions, information and suggestions contained in this letter/correspondence are for guidance purposes only and are made in good faith. They may, or may not have been validated therefore, you should seek technical or professional assistance or advice before carrying out any of the suggestions, repairs or modifications suggested. They are not the views of the KETTLE CLUB or its committee. Nor are they endorsed by the KETTLE CLUB or it's committee. The author of this letter/correspondence & the KETTLE CLUB cannot, & will not accept any responsibility or liability for any damage caused to the motorcycle or other property, or injuries or death to persons carrying out repairs or modifications suggested in this correspondence. Nor shall any third party make a claim against the author or the KETTLE CLUB or any of its committee for any damage howsoever caused to the motorcycle or other property, or injuries or death to persons or third party carrying out repairs or modifications suggested in this correspondence.