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Post Info TOPIC: 350cc Big Bore Kit for the TTR250 - updates and gossip!


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350cc Big Bore Kit for the TTR250 - updates and gossip!
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Have you had any new figures to compare against the 250?

Eg power/torque/mpg etc?

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Daniel Lee



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Earlier on this thread there is the dyno readings showing what you need to know.

The extra torque is massive, uphill 5th gear and twist of the throttle and pulls away smile

Not sure about the mpg, as I would rather have the extra power and have the Acerbis fitted wink



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Simon said he was getting 65mpg with aggressive use of the throttle biggrin



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Gee Mossproof you deserve a medal for persistence on this project, very well done.
I saw one on Steve’s bike during our visit to his and Lisa’s “Hostel” in July and it looked fantastic.
Didn’t take it for a spin as the Travel Insurance probably wouldn’t have covered “Injury by Motorcycle.”
Good idea to leave the final fettling to the individual Purchasers.
Again, bloody well done.
Cheers
Jeff


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Thanks Jeff. It's been a challenge to maintain morale, but the encouragement on this forum has been great.

@Dan: I swapped the oem exhaust for an FMF Q4, took the airbox lid off and did some jetting and got 25.5 hp @7500, and 21 ftlbs @ 5500. I have not done any porting or polishing and for that to compare so well with the Euro spec Honda CRF450L that costs ten grand I'm really happy!! When I first built my 350 I was braaaping around all over the place just playing with the torque band up and down the revs - not smooth riding at all, and after running in, the first tank refill gave me 65mpg (UK gallons) Since then I haven't measured it again, but more controlled use of the throttle would improve this hugely - I was hooligunning it!

So here we have it folks:

 

 

  • A genuine 346cc – nearly a 100cc increase! The Thumper Racing 325 kit is actually only 315cc.

 

  • Newly cast barrel so you can sell your old one to help fund the kit!

 

  • The barrel has a thicker wall than the original so that, when bored to take the sleeve, it still has plenty of meat left. No oil weeps through cracks in the barrel as has happened to quite a few owners who have used the Thumper Racing 325 kit.

 

  • New liner/sleeve with sufficient meat on it to allow for rebores if ever needed in the future.

 

  • Quality Wossner pistons (made especially for the kit) together with excellent Cometic gaskets are supplied in the kit.

 

  • The only machining work needed by the customer is to bore the crankcases to take the bigger sleeve. Most engineering workshops can do this and it’s not expensive. Circa £30 to £40 in the UK.

 

  • No need to modify the cylinder had or other parts although owners are welcome to improve the airflow by modifying the airbox, gas flowing the head, using modified camshafts with different lift and profiles, free-flow exhausts, shorty headers, larger bore flat slide carbs, etc.  Feedback on any such mods will always be appreciated via the TTR250 forum.

 I think there will be a lot to gain from porting and a bigger/bored carb, for those on the hunt for power. For me the lovely wide torque curve is what makes it such a nice ride so I'll stick with standard carb and a Motad pipe. I look forward to hearing what others can achieve with tuning...

 

 



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Great news. Congratulations on your efforts.

Bugger on the timing though- I just bought a new ute today, so unfortunately I can't put my hand up to be in the draw for one of the first few. Hopefully I will be good to go in a month or two. I honestly expected the kits to be a bit dearer, but with a rough AU conversion of $1437, I'm happy that they're not. As mentioned in an earlier post: I will soon be able to build the bike that I want.... Simple, light, air cooled, with plenty of torque.

Please keep us informed of your production numbers & availability as you progress.

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Hi guys congratulations, all your years of hard work have finally paid off. I'm definitely interested in the kit steve so please put my name into said hat 🙂

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Incredible job! Will there be more batches of these being made in the future?

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There could be more batches later, but as the price of the pistons went up by 30% from the initial quote, and the castings up by 10%, they are going to get more expensive...

First batch has to sell reasonably quickly before I contemplate going through the hassle again!

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I definitely want one... Just need a little time (month or two) for the finances to settle.

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I'd like to be entered into the draw please...

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Hi All

Right A draw has now taken place 

There was 3 kits available in the end, as Brian does not need his for a moment (busy with other stuff) and he will get one of the next batch that are already on order.

Simon, Giles and Dan have got them

Jordan you are first down on the next batch, shouldn't be very long.

Could you all Pm me your details and we can sort the rest out.

Cheers 

Steve

 



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Great news, cheers all!:)

Just had a thought...

Simon mentioned reboring once the barrel is warn but your piston was bespoke to the kit? I'm just wondering after inget back from the future Russia trip what happens if I need to go say +0.5mm, how would that work because surely I'd need a bigger piston?

Also Steve I've just mp's you so we can sort it all out:)

Thanks,



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Oversize pistons should be fine from Wossner and there should be enough thickness in the sleeve.

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Re sand cast finish.

Have you seen the price of a sand cast Honda 750/4?



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Dan had a good idea, you could 're sleeve the barrel and get new rings if ever needed?



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Yay!!! Super excited. I just picked up a '94 ttr. I plan on shipping it to the states next year. Hoping to turn it into a 350...!

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350
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What happened to the 350?!?



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2 are on the road, 3 customers are building theirs and more kits are on order



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RE: 350cc Big Bore Kit for the TTR250 - updates and gossip!
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Have merged Michael's new thread to keep things tidy! Hope that's OK.

Reminds me that I need to prepare the "Weston" TTR I bought ready for my own 350 kit wink

Brian



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TTRfan wrote:

Have merged Michael's new thread to keep things tidy! Hope that's OK.

Reminds me that I need to prepare the "Weston" TTR I bought ready for my own 350 kit wink

Brian


 wondered where it had gone, forgot to say hello Michael



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Thanks guys. Couldn't find the thread!!!

Well, what does one have to do to get their hands on one?!?! Got a bike that needs one....



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i have taken a deposit for one of the next batch (4?) Brian has his name on one as well, so should be 2 left for sale? sure Simon will let us know when he wakes upwink

 

edit spelling, fat fingers on small phoneno



-- Edited by ttr steve on Sunday 20th of October 2019 10:46:36 AM

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Hey Steve, just got a tax rebate so this is sorely tempting..

Does the kit turn the TTR into a wheely machine? :)


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Simon is wide awake and restoring a Serow for a customer
Applying gentle pressure to the machine shop. I think he's done the first cuts...
This batch is 6. Could be 8 if you're prepared to put up with really ropey castings. (I'm not.)
The 350 really livens up the ttr, especially if you've got a freer flowing pipe. See Brian's comments a page or so back from when he came by for a test ride.

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robs wrote:

Hey Steve, just got a tax rebate so this is sorely tempting..

Does the kit turn the TTR into a wheely machine? :)


 oooh yes (if you feel the need)



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I love my ttr but would like a bit more power. I'm in a difficult spot because today a friend offered me a really nice DRZ for cheap.

I would love to do the 350 kit (already have spare engine casings) but I just don't have the time at the moment. I might have to let the TTR go, but it'll be a sad day.

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Righty ho. Steve, I'll give you a call tonight, morning for you, and organize payment and shipping. Any idea how long untill they are ready for shipping? Also, any markings on the casting?

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best to email sales@totallyttrs.com, but happy to take a call



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Emailing now regarding a deposit..

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AAAAAaaaaarrghhh!

Spoke to the machinist today. Realistically we are looking at 4-5 weeks 'till the next batch will be done. He has felt the strength of my displeasure, but there is nothing I can do but wait. I am really sorry this is taking sooo long, particularly for Brian who gave up his kit to sell on the understanding that the next batch would not be long, and sorry to Jordan who was the first to enter the first batch lottery, and missed out. It will happen guys... eventually.

There are no markings on the castings to suggest capacity, if that's what you meant Micheal?

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I'm having a hard time coming to terms with selling the TTR and I would love to buy this kit. If i get the engine casings I have machined down, would anyone here be willing to do the conversion for me? Obviously I will happily pay for the service! Due to living in a van I don't have a workshop or a garage or anywhere where I could do the work at the moment.

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My ttr350 runs!!! No.3 I hope!

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Well done Daniel!  



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TTRfan wrote:

Well done Daniel!  


 good work  have you worked out your jetting, mine and Simon's were completely different I think confuse



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I've finally got my finances sorted and have emailed my request through.....

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Cheers guys,

I used 142 50 middle position, 1.8 turns out. I pressed the button for a second with the choke out and it instantly started. I only ran it for like 3 seconds as it was late(ish) so i'll see how it is at the weekend:) cheers for all your help!



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Hi Steve, every time that I try to reply to your email, it bounces back saying that your inbox is full....

Anyway. I did receive your email this morning. Keep me posted, let me know when you need some money, and how much.
I'm sure I'll need a kit for my sons bike as well at some stage, but I'll deal with mine first (unless there's a discount in buying two at once???)
Cheers,
Mark

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yes I have been having email problems, all sorted now I thinkconfuse

Will keep in touch and sorry no discount, we only just make enough money to make the 350 projects viable. 

Steve



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3 years my TTR has sat dusty in the shed....and tonight I find this thread.



Consider my interested piqued.

Very piqued

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Well considering it's taken about 3 years to get to this stage of having 3 running engines and a new batch of kits close to ready, you must have just missed the first rumours

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dlee22, how is your bike? I know you were having a bunch of problems. I'll be swapping in the 350 early next year. Just wanted to see if you had found out what was causing some of your problems.

Cheers,
Michael

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Hi Michael,

All good now thanks! Sorted the inlet valves now and I think it's better thankfully!

 

That'll be great when you are done! The 350 feels stronger but I haven't bedded her in yet so haven't given her much yet.

 



-- Edited by dlee22 on Monday 25th of November 2019 11:38:33 PM

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Great! So, that's three working 350s! Can't wait to get mine.

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New batch of barrels should be in the chuck jaws by tomorrow afternoon. Fingers crossed...

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Everyone is on a wind down for Christmas now as wellno



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Ah, right. Kind of forgot things stop at the end of the year. Oh well. looking forward the new year!! Also, Steve, how do you take payments? Pay[al?

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No no, he is machining as I type. Just he has a long queue of barrel jobs and we're one of many. Mostly 2 smoke barrels for classic bikes, and the fact that he is so busy is recommendation, but no consolation.

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I'm so keen to receive one of these kits.... I just hope that there's enough being built that I can actually get my hands on one. It'd be a good feeling having the first in Australia. (Any other Aussies ordering?) If there is enough being built to meet the demand, I'd actually like to buy 2 kits - one for my sons bike as well.

I should have my cases split by the end of the weekend.. And I've started work on my bike build. This is going to be something unique. One of the main differences (from the Oz models at least) is that due to me spending a lot of time in the desert (regularly riding in temperatures 30c to 40c ) I'll be adding an oil cooler; head stem mounted from XR400; I just have to figure out the fittings for the casings (is there any aftermarket available? so far I've only found an occasional Raid cooler second hand.) I'm sure that I've seen a link somewhere in the forums.

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There are a few threads that might be helpful - just search on "oil cooler" wink



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