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MT2
Feb 19, 2024 11:08:28 GMT 1
Post by muttsnuts on Feb 19, 2024 11:08:28 GMT 1
do you have space to get a radiator fitted underneath the engine between the crankcases and exhausts?, I know it sounds bizarre, but if you think about air cooled 4 strokes thats exactly what they do with them, fit them very low down, or even under the engine with air being directed through it using scoops/ducting, the other option is like the Benelli tornado and have the radiator mounted under the rear seat cowl
Another option could be to run a pipe (22mm or the likes) left to right across the front of the engine between the exhaust headers, just thoughts ?
HTH
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Post by muttsnuts on Feb 19, 2024 11:01:38 GMT 1
This old chestnut, anyway, after a lot of effort I've managed to get some 21mm and 24mm clutch damping rubbers made out of the correct material and the correct hardness (Shore 90/95) Over the years I've serviced and overhauled alot of clutches and the common theme with the current aftermarket rubbers is that they are made from the wrong material and the incorrect hardness, the picture below is an example of what I see far too often, 4 smaller (21mm) pucks where fitted under a year ago by the bikes owner, as you can see, the 4 aftermarket ones have disintegrated, it is not unusual for clutches to have both the 21mm and 24mm pucks fitted, its also not unusual to see "D" shaped 24mm pucks either From the many clutches I have stripped the one thing I have learnt is that Yamaha certainly appeared to fit whatever they could get their hands on, so far I've identified 4 different style pucks, varying in 21mm and 24mm diameter, some are round, some are "D" shaped, some have all the same size fitted, some have a mix Anyway, I've now had some 21mm and 24mm pucks made (1000 of each), I'll pop these on my web site, if anybody needs any just let me know, please note I am the only one as far as I know that has the 24mm pucks, if you have "D" shaped pucks then you need the 24mm pucks, then I just trim them into the correct "D" shape
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MT2
Feb 19, 2024 10:26:19 GMT 1
Post by muttsnuts on Feb 19, 2024 10:26:19 GMT 1
cooling is a balance, if it goes through the radiator too quickly then the engine will run hotter, if it lingers in the radiator too long then it can run too cold, but that is only part of the story, flow rate is important, but if your pump flows more than the radiator then you can get "buffetting" which causes hot spots as the water is effectively "backing up" at the radiator inlet, conversely if the flow rate is too slow then the engine can run hot as the cooler water isn't getting to the engine quickly enough
The one area people miss all the time is the surface area of the radiator, that is more important than its capacity (to some degree), you need a big surface area, most LC's/Hybrids etc get this wrong, my simple test is to stand in front of the bike and look at the radiator, as a rule of thumb, whatever you can see of the radiator at its level is how much air will see it (leaving aero-dynamics out of it for now), so if the front wheel/mudguard and forks are covering 80% of the radiator then the chances are only the very outer edges of the radiator are actually cooling, the quick and easy fix for this is to make and fit some side scoops on the radiator to direct cold air over the centre of the radiator - testing on the dyno has shown between 6 and 8 degrees drop in temperature by doing this alone
HTH
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Post by muttsnuts on Feb 19, 2024 10:15:19 GMT 1
Left crank seal leaks. But could it explain my symptoms? Anyway I have to open the crankcase. [video src=" Left crank seal leaking by xian911, on Flickr"] [/video] [/quote] that doesn't look like a genuine seal to me, looks like one of thecheapo ones you can get, either way, it needs changing To answer your question, yes that will cause the symptoms you have been experiencing
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Post by muttsnuts on Feb 19, 2024 10:12:40 GMT 1
I have a durometer for measuring shore hardness, I can check it, suspoect it will be around 70 to 75 shore, the tolerance is normal +/- 5 on the hardness scale anyway
New ones are still available from Yamaha and TBH making some isn't that easy, I've just been through the whole pprocess of getting some rubber made at the correct hardness/size etc and that was a learning curve for sure !
Swapping the bushes isn't straight forward and as others have stated, you have to be super careful not to crack the cases, I've made a puller and fitting tool up as I do a fair few and even with that, its still a good hours work at least to swap a set out
HTH
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Post by muttsnuts on Feb 14, 2024 19:48:15 GMT 1
back to the point of the post, as most have said, you want it tuning for reliability really, its ok making it do big power but the bores (especially on YPVS barrels) wear very quickly around the transfer port area as there is very little metal to start with, as most have said, try and leave the inlet bridge alone as otherwise it accelerates the wear in the middle of the barrel
The exhaust port is already pretty good on the YPVS, so that can be left to a large degree (widening it a little at the top half helps), a good clean up of the rough casting in all of the ports also helps, as does aligning the power valves perfectly, that alone can be worth 5bhp if they are out of whack (which most are)
HTH
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Post by muttsnuts on Feb 14, 2024 19:40:02 GMT 1
My stroked and Mutts ported YPVS should apparently go 5000 miles in between top end rebuilds, when it ever gets completed . got several that have done over 8000 miles now and still going strong
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Post by muttsnuts on Feb 12, 2024 17:01:19 GMT 1
I am just about back up and running now after my surgery New name Davina? Muttsnonuts 😁 Steve cheeky fecker....... had a penis reduction operation........ LOL
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Post by muttsnuts on Feb 12, 2024 15:11:05 GMT 1
made to work with stock jetting, might be a tad rich, but as you know, every engine is different, just be careful and check your plugs etc, you'll notice a massive difference with mid range pipes fitted
if you need it back on the dyno give me a shout and I'll sort something out, I am just about back up and running now after my surgery
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Post by muttsnuts on Feb 3, 2024 20:37:43 GMT 1
I tell ya, its Aliens............
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Post by muttsnuts on Feb 2, 2024 21:04:33 GMT 1
its Aliens, they are coming to probe you while your asleep............
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Post by muttsnuts on Jan 29, 2024 21:29:53 GMT 1
hopefully you have kept all of the original internals as the yambits kits aren't good, one thing that is very wrong in the kits is the air screw, I've had 200 made that are an exact copy of the original Yamaha one, there where 2 types of air screws, the yambits kits contain the wrong one, only the very early carbs had the early style air screw in
Even if you turn the air screw fully in it will still be too lean
If you have the original metal air screws then I'd refit those for a starter for 10, seat them as the yambits ones will have screwed the seat up a bit, then turn them out 1 full turn and see what it does then, I'd also chnage the needles back to the 5K1's as again the needles are the wrong ones
I am assuming the carbs are 4L0-01's if not, then the needle advice is mute, but the air screw advice still stands
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Post by muttsnuts on Jan 26, 2024 21:07:24 GMT 1
I'll double check, but think the last set I sold was £900+vat for barrels, pistons and head
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Post by muttsnuts on Jan 23, 2024 22:02:17 GMT 1
yes I've got some, not run them yet, but checked the porting etc, all good and they are good quality, can get them way cheaper than that quoted on ebay though
planning on running them in the coming weeks, just need to find a slot in my diary !
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Post by muttsnuts on Jan 18, 2024 22:34:26 GMT 1
I do a custom bush service for the clutches, make a new bush to fit you gear and bearing sleeve, takes out all of the wear
Not too far aay I'll be offering the option to rerplace the bush etc with needle rollers, will involve a new kick starter gear, needle rollers and a new bearing sleeve, not sure on price yet, but that will remove the need to ever worry about it again and reduce the friction quite considerably
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Post by muttsnuts on Jan 17, 2024 19:42:23 GMT 1
that will probably clean up, if your close to me, pop in and I'll measure/check them for you
Also, I'll be doing resleeving very shortly, now that I've sorted out a few things.......
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Post by muttsnuts on Jan 16, 2024 19:09:40 GMT 1
yep, I do rebores, based in Wetherby - LS23 7FL
75psi is very low, I am surpried it started TBH
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Post by muttsnuts on Jan 15, 2024 19:03:32 GMT 1
one big driver on costs is the electric cars as well, claims because of fires in garages that then burn the house down are on the rise, it actually costs more to insure your electric car if you put it in the garage over night and charge it ! - plus all these "keyless" stupid cars which are a peice of pish to steal - bleeding modern rubbish made by idiots who think electronic gizmo's are unfallible
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Post by muttsnuts on Jan 15, 2024 18:56:44 GMT 1
fantastic work, all by hand, hence why so expensive......finding any decent pattern makers these days is very hard, looks like they might have bagged the last few people who can do it properly !
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Post by muttsnuts on Jan 15, 2024 15:26:32 GMT 1
looks fantastic, well done, love the graphics..........
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Post by muttsnuts on Jan 13, 2024 19:00:35 GMT 1
first off welcome to the forum
now to your head issue, things to check
1. Do you have the correct washers under the head bolts - if you don't get some as the head bolts can "bottom" out on the studs so the torque wrench will click, but the head isn't clamped - its a fairly common problem 2. If you have the head off, lift one of the barrels off and check the studs are fitted the correct way round - they have a long thread and a short threaded end, the short threaded end should go into the crank cases, if they are fitted the wrong way round then the head bolts can "bottom" out and again the head won't get torqued done even though the torque wrench will click 3. Check the barrels are level and have even "deck heights" 4. Check if the barrels have been relined, if they have, you may need to have these checked for it being done correctly - ones done by SEP engineering where known to have issues 5. Check the head isn't warped, if in doubt, get it checked or skimmed to be sure 6. head gaskets, if using a genuine one, then torque down to 20/22ftlb's is perfectly fine and what I use (ignore the haynes book of lies), 18ftlbs is a little light, if using a pattern head gasket, fit it dry, don't fill the engine with coolant, run it up until the barrels are warm to the touch - you won't damage anything, let it cool down, retorque the head bolts, fill with coolant, run up until at working temperature, turn off and let it cool down again,. retorque the head, then you should be fine
HTH
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Post by muttsnuts on Jan 13, 2024 18:51:23 GMT 1
that's Stuart Bennetts bike, he's a member on here iirc
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Post by muttsnuts on Jan 7, 2024 18:50:44 GMT 1
New pistons/rings and cylinders rebored. what they have been, or your going to ? A fresh top end should read around the 125 to 130psi mark, don't stress if its slightly less or more, there are a number of factors that affect it but it should be well above 100psi no matter what
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Post by muttsnuts on Jan 7, 2024 13:50:30 GMT 1
like Jon, I was staggered during my time in IT how business where run
I was working in Japan for one of the biggest companies in the world back then (1997 to 2000), they had just bought out a big Japanese company, I was responsbile for taking over the data centres and migrating their systems into our systems
Their systems where only accurate to 4 decimal places, our system was accurate to 32 decimal places, when we migrated their data into one of our test systems the books didn't balance, they where out to the tune of $120 million dollars, and more importantly a deficeit at that to the Japanese government !
We flew over an army of accountants who worked for 3 months solid "massaging" the data and fixing reconiliation issues until the deficeit sat at $56 million dollars, after a big senior management meeting it was agreed to the "write" the $56 million dollars off as a loss, the country director then just authorised a payment to the Japanese government for that amount - truly staggering, and yet nobody ever questioned where that money had gone - truth was, it hadn't gone anywhere, it was simply a computing/coding issue coupled with accuracy within the two systems
These problems still exist today in many systems, and don't get me going on banking systems.........it would make your toes curl what they get upto !
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Post by muttsnuts on Jan 7, 2024 13:37:31 GMT 1
if I remember correctly these are too short in overall length, but I'd need to check I am sure somebody will be along shortly who will either correct me, or confirm my old brain isn't completely useless
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Post by muttsnuts on Jan 7, 2024 13:18:28 GMT 1
as some of you know I worked in the IT industry from 1987 through to 2007 and then part time until 2012, anyway, Fujitsu was one of the companies that tried to get me to come in and solve some of their issues in Bracknell, I turned them down because they didn't have the due diligence in place at the time and it was well known within the industry that was the case.
Given the work I did, I know full well access is ALWAYS possible from a systems point of view, there is no such thing as unable to access the data, I spent years working on ways to audit and record any data changes, if it was so desired using a high level account at the back end, access was always possible and data could be changed with that access and it would bypass any auditing checks in place as it was being done at "data" level.
The logging in as somebody else was common place, and without their knowledge, I wrote a program that would reverse the passowrd encryption used on a system so that I could login as "Mr Smith" if required, sometimes it was the only way to figure out a problem they where having, but that type of usage was strictly controlled and logged in the systems I built and looked after, you had to jump through loads of hoops for me to grant that access and it had to be signed off at the highest management level
There are far more checks and balances in place these days and even high level access should be tracked and logged, back then it was very rarely ever done by companies, it use to drive me nuts, I had so many arguments with people/management about it, use to boil my piss
I watched the program and it reminded me of all the reasons I left and went back to my engineering roots, the people changing the data (and they know who they are), should do the right thing and come forward, they will have altered thousands and thousands of records and data, which I am sure probably "over inflated" the post offices profits etc
The one thing I am puzzled by, is why the people who where made to pay money to the post office etc haven't raised this with the authorities/police as "theft" as that is exactly what it is, now that it has been proven they where innocent, then any monies taken was done fraudalently
I hope those responsbile get what is due to them, but as I suspect they won't as usual, the whole thing stinks........
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Post by muttsnuts on Jan 7, 2024 12:55:29 GMT 1
ok back to basics, what's the compression pressures for each cylinder - I know you said "within tolerances" but what are the pressures ? I just checked on pictures I took and now I have a doubt being within tolerances... 75 psi on both cylinders. Too low isn't it? Not sure I did it correctly (not full throttle) Will redo it tomorrow. thats buggered, even with WOT it won't go up by much, be surprised if you get more than 85psi
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Post by muttsnuts on Jan 6, 2024 23:44:59 GMT 1
ok back to basics, what's the compression pressures for each cylinder - I know you said "within tolerances" but what are the pressures ?
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Post by muttsnuts on Jan 6, 2024 23:43:01 GMT 1
it was me who had a failed lab seal, but that was on an RGV250 (the lab seals are sh*te and can fail due to the ethanol in the petrol) They have a rubber outer to the seal, was it a Japan seal ? not sure Paul as it had all disintegrated when I got the crank out so couldn't tell what make it was
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Post by muttsnuts on Jan 6, 2024 20:57:56 GMT 1
it was me who had a failed lab seal, but that was on an RGV250 (the lab seals are sh*te and can fail due to the ethanol in the petrol)
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