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Current Topic Rating: | Join the Forum to Rate this Topic at: Classic Motorcycling Australia Forums
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 03 May 2010 : 5:30:02 PM
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Anyone here ever raced a kettle?
Just thinking about what to do for the next project and would like some opinions of running/racing this bike.
Cheers and thanks
Nic
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CB72
Level 2 Member
39 Posts |
Posted - 06 May 2010 : 04:13:43 AM
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Not as such, but we have been involved in a number of interesting GT750 based projects including a couple of reed valve conversions and a couple of 100+ hp motors.
Of course Brett deStoop is the expert.
email me and I'll try to point you in the right direction. |
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team400
Level 1 Member
New South Wales
19 Posts |
Posted - 06 May 2010 : 08:19:18 AM
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Nick Leigh Corbett has one,he raced for a while. I think he's bringing it back out,He's the boy to talk to. Ring me. Sir Al |
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Geoffpgrant
Level 3 Member
South Australia
204 Posts |
Posted - 06 May 2010 : 3:56:30 PM
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Hmmm my reading of the rules suggests that reed valves are illegal for P4 which is where you would normally run a 'bottle. I suspect you would have difficulty being competitive in P5 even with reed valves.
Of course if someone can tell me that reed valves are OK for P4 that would be fantastic! I'd love to instal them on my H2...
Geoff Sidecar #30 |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 08 May 2010 : 09:24:12 AM
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I think they are illegal unless originally fitted by the factory. Not sure I want to go P5 unlimited fast yet either.. |
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CB72
Level 2 Member
39 Posts |
Posted - 11 May 2010 : 04:27:05 AM
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Reeds are not an available option on a GT750, though I have seen a very neat cheater with reeds that was hard to tell from stock. You could also get away with John Aylor's H2 type reeds which fit into the port in a rather unconventional way.
In P4 format with the right crank pipe porting and head, 120 rwhp should be possible. The bike will still weigh a ton until the chassis is all replaced with lighter stuff and better brakes, but you could be competitive.
Bigger motors are possible, but the cost is likely to start to spiral upwards. Get a decent ignition and I'd recommend You must be logged in to see this link. as a modern ignition that is programmable via your PC.
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GD66
Senior Member
Western Australia
390 Posts |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 17 May 2010 : 3:25:43 PM
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Beauty! Thanks for the links! |
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john
Forum Moderator
Victoria
3130 Posts |
Posted - 17 May 2010 : 9:37:49 PM
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Sounds like an interesting project, keep us posted. Bruce Collins is trying to race one in an outfit at the moment. |
John Daley Sidecar #68 ' there are those who do, those who dont do and those who undo. We must lampoon the latter." |
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GD66
Senior Member
Western Australia
390 Posts |
Posted - 18 May 2010 : 8:59:42 PM
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Merely an observation on that subject : it appears to the uninformed outsider that he's struggling a bit to get it going just how he'd like. The rig looks a million bucks, and has a set of expansion chambers on it that are just sexual, but it's taking a while to get it into flyer status. Just a matter of time, I reckon, so watch this space. Good to see his ex-passenger, Chris di Nuzzo, back on the track again also, in the chair of the Irving Vincent. Great to see stars of the past back racing with the historics, hats off lads. Regards GD |
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dinkiracer
Level 1 Member
Victoria
5 Posts |
Posted - 23 May 2010 : 02:56:25 AM
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Hey- there were never any that went quick back then.They are a very heavy bike that doesn't really like changing direction quickly when leaned over-unless that change of direction was the start of a highside!Unless you could make the engine a lot lighter so it didn't push the bike so much on lean in the middle of corners you'd be battling the old girl to get it to turn in on tightening radius corners,and if there were two corners following each other and someone was in front of you-these characteristics would mean you'd just have to follow them round-so it might just be a waste of time in the end -no matter how fast you got it to go,as your opponents would soon realise this-and they could just slam in front of you in the braking area and you'd be roadblocked.Without wanting to put you off something technically interesting(as the crank was well lubricated so could make a lot more power without being as fragile as some other 2 strokes)Its probly going to be a lot of effort just to get baulked all the time.Maybe-if you don't have any special affinity with them -it might be better to develop something that handles a bit less like a car.They do sound good with a decent set of chambers on em though!.A guy we knew who was quite fast in the early seventies had an M model with braces in the frame ,a home made swingarm and a fair bit done to the engine, was quite quick coming out of corners,yet he was very strong armed and used to get chucked out of the saddle often if it started to flick on him.Ican think of a few other bikes that were far more user friendly;the second model machIV,surprisingly being one of them.That being said you could make a great looking racer that sounds excellent and in a reasonably mild state of portng -with good chambers would be fairly reliable ,good luck |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 23 May 2010 : 10:36:54 AM
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I thought everything from the 1970's handled like a car? ;)
I'll have to give it a go anyway, I've got my head set on it now.. |
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dinkiracer
Level 1 Member
Victoria
5 Posts |
Posted - 23 May 2010 : 9:38:33 PM
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Thanks for your friendly reply.You are a bit right-my MOTO GUZZI 750 S3 (ex-BOL D'OR private dealer endurance racer )and LA PECA, Eddie Lopez'specially fettled early model 900ss are but two bikes that I owned which are fabulous handling bikes/just way too long for most OZ tracks.Yet to be decent in retrospect-many of the home built GS1000improved tourer racers punted by privateers were reasonably good and a well modified Z1000,although a big handful,was a sweet tracking sort of a bike once braced from steering head to rear tank mount(they bucked hard though when the time was right 4em!)Yet the bottle was never really a prospect-more perhaps due to the overt dominance of TZ's,Imean -you only had to be on track in a practice session when Warren willing came past and there was not much point deciding to race against that bike/rider combo.So maybe in the class that is there now in 2010 -there is a very real chance you might get enough performance to run well .We modified that 750M after the swingarm was built out of sections of mild steel-braced ala WESCooley's AMA gs1000.What we found was that the good solid braced swingarm resulted in the the pivot area to move around-causing the thing to feel a bit vague.So even if you just box it in above the pivot point with some plate that duplicates the pivot mount area-yet on the inside of the frame tube with transverse webs welded between your new gusset and the original pivot plate(if you are looking at a GT750 frame where the swingarm fits in you might get what I'm saying)Then you could possibly decide by using some development brass steering headset shells of different offset and centrality that the rake is stupid-and by trial and whoops(-Hopefully not)error!end up knowing how much and at what angle to cut and shut the steering head fixture of the chassis Any purists who don't like hotrodders chopping up original bikes-please leave the room!. This will make a lot of difference to that understeer tendency-and you might discover that the bike is better if its a bit shorter.It would be impressive to see a fast suzuki 2stroke serve it up to the modified 4cylinder bikes.(Hopefully you aren't going to tell me such changes are illegal)I'm curious and wish you very good luck and hope its a lot of fun to be developing.That purple Go-kart book written by the guy from Maitland has recipes and ways to calculate chamber cone sizes for chambers on bikes from that era and may be a big help.
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matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 23 May 2010 : 10:40:41 PM
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i remember a post classic race at oran park back quite a few years,main combatants were Eddy Poulcher on a Tr "ish" 750 kettle,& bulldozer muldoon from Bathurst on at the time a big bore Xcess yamaha twin,kettle had the legs down the straight every lap,but yamaha back underneath thru the twisties (GP track),had the crowd on their toes for lap after lap,can't actual remember the outcome,but was awesome to watch,wheres Al,(sidecar21) GD66??,should have kettle imput, |
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GD66
Senior Member
Western Australia
390 Posts |
Posted - 24 May 2010 : 12:16:18 PM
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He's still about, and threatening an imminent return to the track. He's also a commissioner, and advised us at the club meeting last week that commission minutes are due to be released on the MA website, but as usual there's only a small window of opportunity for them to be viewed, considered, and commented upon before input is closed off. |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 24 May 2010 : 6:32:05 PM
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Well good news, looks like she's a goer!
I'll post a pic once she arrives. |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 24 Jun 2010 : 8:30:58 PM
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Well she's due to arrive this Saturday morning.
Here's a pic, maybe someone on here has seen it going around in the past? She's been stored for the past 8 years.
Not the best looking bike on the block but, she'll clean up ok ;)
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Geoffpgrant
Level 3 Member
South Australia
204 Posts |
Posted - 24 Jun 2010 : 8:53:17 PM
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Hey that is cool. Look forward to seeing it out there.
And Barbara likes that you have a Kombi too :-)
Geoff Sidecar #30 |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 24 Jun 2010 : 8:56:49 PM
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Not my Combi, that's a pic from the seller :) |
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Bummers
Level 3 Member
Queensland
244 Posts |
Posted - 24 Jun 2010 : 10:30:16 PM
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Beautiful - 2 stroke POWER!! |
“Racing is life. Anything before or after is just waiting.” Steve McQueen |
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Alan Cotterell
In a time out state
Victoria
421 Posts |
Posted - 25 Jun 2010 : 08:27:37 AM
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My brother raced a GT750 in a speedway sidecar in the early 70s. His hand was never out of his pocket. You have to remember that if you damage anything in the motor, it's always times three to fix it. A kawasaki H2 is a much better option. I'd point out though that in the 70s Pat Hennen had one of the works 750s with the trick frame, lay down shockers etc. and that was a good jigger. It raced at Sandown, Calder, and Laverton. If you are going to build a replica that would be good. Have a talk to Keith Roberts at Mt Macedon, he has an ex-Barry Sheene GT750 which gives him a good scare. As far as reed valves are concerned, I think the guys would find it very hard to nobble you, if you fit them. |
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Alan Cotterell
In a time out state
Victoria
421 Posts |
Posted - 25 Jun 2010 : 08:30:46 AM
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Mick Pettifer raced a GT750 for a while, probably still has it. |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 25 Jun 2010 : 5:54:02 PM
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I did consider a H2, they are just getting too expensive now. There seem to be plenty of gt bits at a reasonable $.
Thanks for the info.
Cheers
Nic |
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Alan
Forum Moderator
Western Australia
353 Posts |
Posted - 25 Jun 2010 : 6:43:26 PM
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Hi Nic, I raced/rode a sidecar with a GT motor in it for quite some years and have just changed over to Honda. Forget a H2 they are more readily tuned and are lighter but are far more fragile. If you get tempted talk to Neville Lush who is probably the best H2 tuner/mechanic in the country and probably still has his solo and sidecar both H2 powered. The Suzuki is a very robust motor and the most trouble I had was with clutches, the baskets break up, always ensure you have the ones with a metal band around the outside. The cranks are very good, the gearbox is almost unbreakable and so on. Limitations are with porting as it is easy to break through into the water jacket if you arent careful, Dean Harrison was good with these but unfortunately he is no longer with us. I can help with some tuning tips , if you P.M. your address to me I will dig out what I have and send it to you. There was a guy in Vic who raced one not so many years ago called Herbie but I cant remember his surname, I did run him over at Mallalla though, I bet he remembers my name. Dont be tempted to go to big with your carburetors either, 38mm are ok but I found 36mm the best. If you dont have electronic ignition make that your first move. Thats about all for now but if you want some help PM me and I will give you my proper email, phone and mobile. Dont consider reed valves, you will get caught.
Alan Sidecar 21 WA |
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Geoffpgrant
Level 3 Member
South Australia
204 Posts |
Posted - 25 Jun 2010 : 6:50:37 PM
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That would be Herbie Havard (if I remember correctly). He is not in Vic any more and if you PM me I can probably find an email address and maybe even a ph contact for him... He loves talking Waterbottles... Geoff Sidecar #30 |
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Alan Cotterell
In a time out state
Victoria
421 Posts |
Posted - 26 Jun 2010 : 08:33:44 AM
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The first GT750 I ever saw raced was at phillip Island, Hans Hari had it (Steve's father) It was extremely fast in a straight line. I've ridden one of those old kettles, and I believe the steering geometry is suspect. Certainly the racer Keith Roberts has, has too much offset on the forks! If you want a good scare....? |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 26 Jun 2010 : 08:45:55 AM
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Well you never know, a nice frame might pop up one day for sale, I just want to get out there for more races and have some fun. |
Edited by - NicM on 26 Jun 2010 08:46:40 AM |
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Alan Cotterell
In a time out state
Victoria
421 Posts |
Posted - 26 Jun 2010 : 08:56:49 AM
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I believe one of the GT750s that Hennen rode had a Rickman frame. It'd be worth rigning Rod Coleman in NZ, if he's still alive. Hennen's bike was the most developed GT750 ever raced. In those days that stuff was pretty much unobtanium - different story now! |
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NicM
Level 2 Member
Victoria
85 Posts |
Posted - 26 Jun 2010 : 7:37:05 PM
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Well I have to say, faaaark it's heavy! Think I'll be hitting whatever I can with the grinder.. |
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NicM
Level 2 Member
Victoria
85 Posts |
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nuggetsdad
Level 1 Member
Victoria
1 Posts |
Posted - 05 Jul 2010 : 6:50:16 PM
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Hi, I realise that this post is almost 2 months old, however I am ery interested in your comment regarding a reed valve conversion to a bottle, that appeared almost stock, can you provide any info?
quote: Originally posted by CB72
Reeds are not an available option on a GT750, though I have seen a very neat cheater with reeds that was hard to tell from stock. You could also get away with John Aylor's H2 type reeds which fit into the port in a rather unconventional way.
In P4 format with the right crank pipe porting and head, 120 rwhp should be possible. The bike will still weigh a ton until the chassis is all replaced with lighter stuff and better brakes, but you could be competitive.
Bigger motors are possible, but the cost is likely to start to spiral upwards. Get a decent ignition and I'd recommend You must be logged in to see this link. as a modern ignition that is programmable via your PC.
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