1200 engine help.

[Tombola]

I done a compression check on my 1200 blandit, WOT I’m getting 110psi ish across all 4 cylinders. Its a W reg and 30k on the clock, Mileage backed up by the mots.

few cc’s of oil picks up compression to 150psi. It’s the cylinders right? Oil like that can’t help the valves seal?

bike wasn’t screaming hot. 
 

it answers the question why it’s always been a pig, I just want some input in case I’m missing something 

Bike has always been rough cold, spitting back, rough coming on the revs, once warm it’s OK ish.

Carbs have been ultrasonically cleaned by Jim at super bike surgery,

valves clearances done and carbs are balanced.

standard zorst, air filter, and new plugs

 

thznks

 

tom

[wraith]

Sounds like bores/cylinders but strange for them all to be low and the same across all 4. 

 

[TonyGee]

new they should be 178psi limit is 124psi.   just for reference.  

[Gixer1460]

30 minutes ago, wraith said:

Sounds like bores/cylinders but strange for them all to be low and the same across all 4. 

Extended oil changes causes all kinds of wear! If the recommended limit is 124psi, then yes its re-bore time and while your in there it'd be rude not to turbo it to help with the breathing LOL!

[wraith]

I'd say at least a 1216cc kit 

[Tombola]

Although that would be lovely… it’s a W reg half faired in maroon 

Can anyone advise on a cost effective repair for a all round hack? 

[TonyGee]

make sure your compression tester is reading right, test it on a known good engine. seen this before when someone used a faulty tester. 

[Tombola]

I will tony I have a decent pressure gauge, just need a reducer to get to the 1/8” bsp of the tester body. 
 

It made good compression with oil in the bores which is unfortunate. But if it’s under reading that could be OK 

[Tombola]

Done another compression test, 110 ish psi across all 4 clyinders, 1+4 being around 115psi. Engine was ran up to temperature this time. 
 

I also borrowed a leakage tester from our garage. I’ve followed the instructions and apparently leakage is low between 25-30% 4 clyinders.

it is a sealey leakage kit so whether it’s any good? 

[wraith]

Never used a leakage tester before.

If the bores or rings are worn, there's 4 things you can do.

1. Cheep way, get another set of barrels and put them on and hope it brings the comp up 

2. Strip the top end, put new rings on the piston's, hone the bores and hope.

3. Combine 1 and 2

4. Big bore

Any of the above you will need to replace head and base gasket and o rings

Sorry and 5. Look for a new engine

 

[TonyGee]

45 minutes ago, Tombola said:

Done another compression test, 110 ish psi across all 4 clyinders, 1+4 being around 115psi. Engine was ran up to temperature this time. 
 

I also borrowed a leakage tester from our garage. I’ve followed the instructions and apparently leakage is low between 25-30% 4 clyinders.

it is a sealey leakage kit so whether it’s any good? 

them figures don't sound good  i think a top end strip is in order and get the measuring gear out  and while your at it a valve job too.  

[Tombola]

Cylinder 2+4 have this in the both bores. Feels completely smooth, but obviously corrosion. The bike had been stood outside for a while, could also be condensation from not running the bike 

Thanks for all your help guys I’ll have to weigh up what to do with it I really didn’t want another project. 

[wraith]

Yes they don't look good, 

If it was me, I'd pop over to the wanted section and see if anyone has a motor they can sell you and sell that one for spair or repair.

In the long run probably the cheapest and quickest way to get the bike up and running again.

[Tombola]

How different is the bandit bottom end to the gsx1100f? 

I ask because I have a bored set of barrels, low comp Mtc pistons, rods, and turbo I was saving for a 7/11 project.

[Wagola]

be rude not to !!

[manden]

13 hours ago, Tombola said:

How different is the bandit bottom end to the gsx1100f? 

I ask because I have a bored set of barrels, low comp Mtc pistons, rods, and turbo I was saving for a 7/11 project.

Looks like that french guys old setup

[Tombola]

If you have a member name or link to the thread would be much appreciated? I’ve had a google of using bandit 1200 bottom end with 1100 top end.