[MillerMatic]

Took my bike to the shop to do a compression test to check the motor and rebuild the carburetor for the new 2bro exhaust I bought and turns out my motor is bad. :butbut: The compression test showed that cylinders 2 and 3 hold a compression of 185 but cylinders 1 and 4 are just at 100. Lesson learned. Always get your bike checked out before you jump the gun and buy $1400 worth of brand new parts and extras. Sometimes we have to get burned in order to learn.:hmmm:

 

[Brandon35]

Might not be just a bad motor... I'd definitely dig into it before you just go buy a new motor

 

[Schooley]

The real question is why you spent more than what the bike is worth in upgrades?

 

[40acres]

Might not be just a bad motor... I'd definitely dig into it before you just go buy a new motor

This times one thousand. Did they mention what was "bad" about your motor? Details please... I'd hate to see you drop a ton of coin when there isn't a need to do so.

 

[Steel]

Definitely check it out first before getting another motor.

Check the obvious thing first which is your valve clearances. After that do a leakdown test, or a cheapo leakdown test and stick compressed air into the spark plug hole and see if air comes out the crankcase or up through the valves/valve seals.

 

[riverszzr]

Leakdown test and see where the compression is going!


How did it run? I assume you had ridden it (ass-u-me)

Many things can cause low numbers- or they could just be trying to fleece you......sad but true

How far from Barber are you (Birmingham, Alabama)

 

[messi4]

Are these motors that cheap that its worth it to throw away instead of rebuilding the top end?

Iv never rebuilt a i4 before.. But the vtwins have always been only a few hundred bucks to rebuild..(keep in mind that's just parts.)

 

[HBR RACING]

Just like going to a doctor, if he tells me I'm going to die I'm damn sure going to get a second opinion. I have a bike shop and I've had people come in and tell me another shop told them they needed a new motor and the motor was fine. I don't just go off a compression check, I always do a leakdown and see what it shows. It may just be a bad valve which is a simple fix.

 

[riverszzr]

Are these motors that cheap that its worth it to throw away instead of rebuilding the top end?

Iv never rebuilt a i4 before.. But the vtwins have always been only a few hundred bucks to rebuild..(keep in mind that's just parts.)

Parts are expensive but for "just" a top end rebuild it is usually cheaper to rebuild the top end than buy a used engine

and it really comes down to what parts does it need

EX valves are $45 each
IN valves are $29 each
pistons are $54 each
rings are $44 each
head gasket is $72
base gasket is $26.........although you could just throw it away and go without
guide seals (16 of those at about $5 each)

considering its age---those gaskets and O-rings inside the head cover for the spark plug wells...... 4 orings at $3 each and 4 well seals at $6 each

and they are nikasil cylinders, no boring (not without getting them recoated)... so you do have to look at that too

I always go after the "known" and rebuild what is there whenever possible, otherwise you could just be buying another hunk of shit that you have to rebuild anyways

Hey I started a couple threads about doing just that..... and that is fucking expensive!

 

[Brandon35]

Parts are expensive but for "just" a top end rebuild it is usually cheaper to rebuild the top end than buy a used engine

and it really comes down to what parts does it need

EX valves are $45 each
IN valves are $29 each
pistons are $54 each
rings are $44 each
head gasket is $72
base gasket is $26.........although you could just throw it away and go without
guide seals (16 of those at about $5 each)

considering its age---those gaskets and O-rings inside the head cover for the spark plug wells...... 4 orings at $3 each and 4 well seals at $6 each

and they are nikasil cylinders, no boring (not without getting them recoated)... so you do have to look at that too

I always go after the "known" and rebuild what is there whenever possible, otherwise you could just be buying another hunk of shit that you have to rebuild anyways

Hey I started a couple threads about doing just that..... and that is fucking expensive!

Is a head gasket really that expensive for the bike? Or is that with machining the head too? Seems awful high for a head gasket but hey, I only did that on a car.

 

[riverszzr]

^ look them up............

them there are Parts pricing just like my post states

Bikes are not mass produced on the scale of cars and car engines, they fit one model typically run for a couple years then changed, so yep parts be expensive.

 

[Brandon35]

^ look them up............

them there are Parts pricing just like my post states

Bikes are not mass produced on the scale of cars and car engines, they fit one model typically run for a couple years then changed, so yep parts be expensive.

Interesting

 

[messi4]

I always go after the "known" and rebuild what is there whenever possible, otherwise you could just be buying another hunk of shit that you have to rebuild anyways

Hey I started a couple threads about doing just that..... and that is fucking expensive!

That's why I have always torn down my motors and rebuilt. Scares me not knowing what I'm buying.
I haven't run into one that's too far gone yet. But that breakdown of parts is a lot more pricy than I'm used to with the vtwins I have rebuilt.

Second hand stuff scares me

 

[MillerMatic]

He quoted me $1100 to redo my current motor but he also said that it could just be something simple or something major. I can get another motor for $550. Riverszzr I'm 3 hours away (according to google maps). And it was a project bike,had been wrecked so I got it super cheap to fix it up. $1100 for the bike and $1400 for all the parts/extras. Total so far is right at $2500.

 

[riverszzr]

3 hours away from me, or away from the engine you can buy?

$2500 into the bike already doesn't sound "cheap" or even a good buy at this point....

And that used engine can have any number of things wrong with it too---the great unknown...

I still say you are far better off to at a minimum find out for sure what is wrong with your current engine before throwing away money on a used engine- that you really should tear apart anyways and see what you have

transmission issues?
rod bearings worn out?
glazed over cylinders from being way overheated?
valves too tight
cam chain and sprockets worn out?
cam tensioner issue?

I simply do not trust used anything, especially a used motorcycle engine

I had to get 3 used to engines to make one good engine, and still spent nearly 1k on oem parts.......... and this is what I have seen on numerous used engine buys

I have like 6 used engines laying outside that were purchased and the owners thought they would just do an engine swap and it turned out those used engines were worse than the one they were trying to not have to fix.

It is a huge gamble to buy used with steep odds against you.

 

[MillerMatic]

Ran but wouldn't go over 5k rpms.

 

[riverszzr]

He quoted me $1100 to redo my current motor but he also said that it could just be something simple or something major. I can get another motor for $550. Riverszzr I'm 3 hours away (according to google maps). And it was a project bike,had been wrecked so I got it super cheap to fix it up. $1100 for the bike and $1400 for all the parts/extras. Total so far is right at $2500.

You need to know what is wrong with it, and a real quote..........not some half assed it could be $1100 but it could be less or could be more


I am getting lost between the 4 of you seeking out engines right now..........

 

[MillerMatic]

3 hours from you. It is a really big gamble but idk what I'm going to do. Thank you everyone for the responses. The value of my bike may not be worth everything I'm putting into it but it's worth it to me. First project bike and it's fun going through all the ups and downs of it. It is a pain and I won't do it again lol but it's nice.

 

[MillerMatic]

With the quote he gave me I figured it'd be better getting another motor for $550 with a warranty. That way if there is something wrong with it I can return it.

 

[Steel]

3 hours from you. It is a really big gamble but idk what I'm going to do. Thank you everyone for the responses. The value of my bike may not be worth everything I'm putting into it but it's worth it to me. First project bike and it's fun going through all the ups and downs of it. It is a pain and I won't do it again lol but it's nice.

I'm right there with you. I bought mine for $2,500, crashed it twice now. On the second motor, rebuilt a third motor and gave it away to a deserving moderator on here, and am now nearly in tears because it has so much that still needs to be done.

Where in GA are you? Because I'm up in Knoxville and am going to be driving down through GA in another week or two headed to Florida and could take a look too if you can't make it out to Riverszzr (I'd recommend it, I'm about to PM him asking a motor question myself).

But if you're mechanically inclined at all, take the bike home, and look into it yourself. The worst thing that can possibly happen, is that you damage it somehow, and end up buying a new one like you're already considering. But more than likely you'll learn more about it then you imagined, get some new testing tools, and probably figure out the problem yourself (and with the help of some people on here).