Engine compatibility 4xv 5jj

[longstreets44]

Hi all,I have just stripped my 5jj engine down to find all of the bores have cracks in them. I have a 4XV bottom crankcase and barrels in good condition and was wondering if the 4XV bottom crankcase can be matted with the 5jj top end ?
The only difference that I can see is the mounting points on the front of the lower crankcase for the AIS system.
Any advice welcome
Thanks in advance
Paul

[malr1]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

[jompy]

5jj crank cases have 4xv on them
From what if read here the bottom ends and heads are interchangeable so basically you can put a 4xv head on a 5pw bottom end .
If you have a look in the projects , 4xv and 5jj sections there should be a number of threads on the subject
Zoran Cuk and Ian Morgan on Facebook seem to know they're stuff

[polar]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

Just had a look at the 5jj manual same bore and stroke.

[jompy]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

Just had a look at the 5jj manual same bore and stroke.

4xv,5jj and 5pw all have basically the same bottom ends with i few different parts

[Danf1]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

Just had a look at the 5jj manual same bore and stroke.

4xv,5jj and 5pw all have basically the same bottom ends with i few different parts

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

[Moise]

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

To be fair, Yamaha did change a lot of parts as you'll find out if you ever buy a used RH 5jj rearset to replace a damaged one. Changes that I know of include the reg/rec, igniter, clocks, mirrors, rear shock, and many more.

It's difficult to understand why Yamaha made so many "upgrades" after 2 years that really make no difference, and then revised it completely to make the 5pw. Maybe their engineers were bored?

It's even sillier when you think that the one modification that improves the 4xv is fitting 5jj pilot jets.

[Danf1]

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

To be fair, Yamaha did change a lot of parts as you'll find out if you ever buy a used RH 5jj rearset to replace a damaged one. Changes that I know of include the reg/rec, igniter, clocks, mirrors, rear shock, and many more.

It's difficult to understand why Yamaha made so many "upgrades" after 2 years that really make no difference, and then revised it completely to make the 5pw. Maybe their engineers were bored?

It's even sillier when you think that the one modification that improves the 4xv is fitting 5jj pilot jets.

Exactly all superficial stuff the “lump” Is the same. All just marketing change up every 2 years keep the “ must Have the latest bikes” spending money. Nothing wrong with it but I remember the fuss at the time and underneath nothing much changed.

[malr1]

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

To be fair, Yamaha did change a lot of parts as you'll find out if you ever buy a used RH 5jj rearset to replace a damaged one. Changes that I know of include the reg/rec, igniter, clocks, mirrors, rear shock, and many more.

It's difficult to understand why Yamaha made so many "upgrades" after 2 years that really make no difference, and then revised it completely to make the 5pw. Maybe their engineers were bored?

It's even sillier when you think that the one modification that improves the 4xv is fitting 5jj pilot jets.

You're dead right there Moise, I fitted 5jj jets last year and the bike runs so much better now.
I've never fitted out 5jj cases with 4xv internals though. but seeing as the guy's 4xv is knackered, I would go ahead and try the rebuild.

[jompy]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

Just had a look at the 5jj manual same bore and stroke.

4xv,5jj and 5pw all have basically the same bottom ends with i few different parts

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

Yeah the 5pw engine transplant was into a 4xv frame in the projects section on here , they guy wanted to run a 4xv with injection , he said if I remember correctly that he was going to make a bracket for the miss aligned head bolt but he had read that other people hadn't bothered and ran them with the frame/head bolt missing , I couldn't do it .
I've brought the longer first gear thing up in here and on Facebook , I hear a fair few people say that the 5jj has a longer first gear than the 4xv , I've had both 4xv and 5jj engines in my bike and the only difference I've noticed comes from the different pilot jets in the 5jj carbs , I've even asked if people can show me the different first gears . From what I've seen the 5pw does have a different first gear and it shows in the parts diagrams , I use Fowlers diagrams all the time but to be honest partzillas are clearer

[jompy]

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

To be fair, Yamaha did change a lot of parts as you'll find out if you ever buy a used RH 5jj rearset to replace a damaged one. Changes that I know of include the reg/rec, igniter, clocks, mirrors, rear shock, and many more.

It's difficult to understand why Yamaha made so many "upgrades" after 2 years that really make no difference, and then revised it completely to make the 5pw. Maybe their engineers were bored?

It's even sillier when you think that the one modification that improves the 4xv is fitting 5jj pilot jets.

You're dead right there Moise, I fitted 5jj jets last year and the bike runs so much better now.
I've never fitted out 5jj cases with 4xv internals though. but seeing as the guy's 4xv is knackered, I would go ahead and try the rebuild.

I've never changed an R1 gearbox myself but I was talking to someone and I can't remember who but they said you can't mix earlier model gearboxs with the 5pw , you either have to use the earlier gearbox or the 5pw . He went into more detail about which gears he swapped out and and in to what model but I can't remember I just know he said the whole gearbox

[Danf1]

Isn't the stroke longer on a 4xv? I'm sure Yamaha changed the bore and stroke configuration after the 4xv to try and calm the motor down a little .
If so, the bores will be narrower and you won't get the 5jj pistons in the holes if that's right.
I assume you have the head off so have a measure.
4xv bore = 74mm
stroke = 58mm
Post your findings, I'm interested to know. I might be wrong.

Just had a look at the 5jj manual same bore and stroke.

4xv,5jj and 5pw all have basically the same bottom ends with i few different parts

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

Yeah the 5pw engine transplant was into a 4xv frame in the projects section on here , they guy wanted to run a 4xv with injection , he said if I remember correctly that he was going to make a bracket for the miss aligned head bolt but he had read that other people hadn't bothered and ran them with the frame/head bolt missing , I couldn't do it .
I've brought the longer first gear thing up in here and on Facebook , I hear a fair few people say that the 5jj has a longer first gear than the 4xv , I've had both 4xv and 5jj engines in my bike and the only difference I've noticed comes from the different pilot jets in the 5jj carbs , I've even asked if people can show me the different first gears . From what I've seen the 5pw does have a different first gear and it shows in the parts diagrams , I use Fowlers diagrams all the time but to be honest partzillas are clearer

No I’ve seen others John a 5pw with a 4xv head to fit in a 4xv frame And I’ve seen an original r71 with a 5pw in a modified frame to accommodate the 5pw mountings, but that was in the mid noughties in pembray. My 4xv is running a super long first gear that works really well on track as it makes dropping from second to first realistic but the gear was made by Nova.

[jompy]

Just had a look at the 5jj manual same bore and stroke.

4xv,5jj and 5pw all have basically the same bottom ends with i few different parts

Lots of rumours after the major overhaul of the 5jj and most of it was cosmetic bollox John. Carb tweaking calmed it down and at the time much was made of the longer first gear that has the same part numbers But the press back then talked bollox all the time to justify their existence. I’m sure I’ve seen someone transplant a 5pw engine complete to a 4xv head as the top engine mountings are different on a 5pw. Fowler’s parts list is a great mine of information when it comes to interchangeable parts.

Yeah the 5pw engine transplant was into a 4xv frame in the projects section on here , they guy wanted to run a 4xv with injection , he said if I remember correctly that he was going to make a bracket for the miss aligned head bolt but he had read that other people hadn't bothered and ran them with the frame/head bolt missing , I couldn't do it .
I've brought the longer first gear thing up in here and on Facebook , I hear a fair few people say that the 5jj has a longer first gear than the 4xv , I've had both 4xv and 5jj engines in my bike and the only difference I've noticed comes from the different pilot jets in the 5jj carbs , I've even asked if people can show me the different first gears . From what I've seen the 5pw does have a different first gear and it shows in the parts diagrams , I use Fowlers diagrams all the time but to be honest partzillas are clearer

No I’ve seen others John a 5pw with a 4xv head to fit in a 4xv frame And I’ve seen an original r71 with a 5pw in a modified frame to accommodate the 5pw mountings, but that was in the mid noughties in pembray. My 4xv is running a super long first gear that works really well on track as it makes dropping from second to first realistic but the gear was made by Nova.

Got ya , i've heard those Nova gearboxes mentioned

[steve888]

Hi everybody . It was my brother Paul who wrote the original post on this thread . He kindly stripped down my 5jj whilst the lockdown is on . I thought i'd update his original post . We decided to transplant the internals of the 5jj into the cases of the 4xv block . I'll send a couple of photo's and update this thread again if anyone is interested in our progress . Nice to be part of the R1 community . Regards Steve .

[jompy]

Hi everybody . It was my brother Paul who wrote the original post on this thread . He kindly stripped down my 5jj whilst the lockdown is on . I thought i'd update his original post . We decided to transplant the internals of the 5jj into the cases of the 4xv block . I'll send a couple of photo's and update this thread again if anyone is interested in our progress . Nice to be part of the R1 community . Regards Steve .

Hiya buddy , thanks for coming back and updating the threasd
How would you fancy starting a thread in the projects section in the R1 area of the forum ? we all love a good read

[steve888]

I'd be happy to Jompy . Not put stuff on Forum's before so i'll see how it goes . Got plenty of pics so i'll get a few posted . The engine should be going back together this weekend .

[polar]

I'd be happy to Jompy . Not put stuff on Forum's before so i'll see how it goes . Got plenty of pics so i'll get a few posted . The engine should be going back together this weekend .

Sounds like it will be a decent job when done, are you replacing the rings?

If you havent got a gasket set yet try partzilla they will be half the price of uk dealer prices

[jompy]

I'd be happy to Jompy . Not put stuff on Forum's before so i'll see how it goes . Got plenty of pics so i'll get a few posted . The engine should be going back together this weekend .

Nice one mate , on this forum we incourage people to join in

[steve888]

I've got all the parts thanks . I managed to get an Athena gasket set from Deutschland Ebay for £125 delivered so hoping the head gasket is gonna be as good as a Yam part ! Not replacing the rings to keep the cost down . They've all been measured in the bores so fingers crossed ! Third gear and it's selector fork have taken a bit of a beating ( probably wheelies ) so I've got a new selector , also from Germany . Hoping this lockdown carries on for a bit so my bruv can finish what he started ! Thanks for the support .

[R1Clarky]

Fingers crossed it all goes smoothly for ya

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