2003 Suzuki w/ bad engine... Any advice?

**fupabox** · 02-10-2011, 07:22 PM

my bad...forgot to add the service manual link...shows chain replacement and tensioner adjustment. section 4.4

http://www.golftechs.us/Manuals/Suzu...YH6_Engine.pdf

**DYNOBOB** · 02-10-2011, 07:34 PM

Big Thanks!!!! That answers all questions.

Bob

**greg0187** · 02-11-2011, 03:55 PM

Hey good work guys. Seems I missed the turn of events yesterday.

**DYNOBOB** · 02-11-2011, 04:56 PM

It did jump timing. Going to be some work to correct...not sure yet if can be done w/o pulling motor. It would be nice to know if pistons hit valves before going too far. As you spin the motor by hand it does get hard in places but I think it's just valve spring resistance.

Again, thanks to fupabox for the manual! This was not going to happen with out it.

It appears you could order timing chain, etc from a Cushman dealer.

Bob

**greg0187** · 02-11-2011, 06:45 PM

Makes me wonder if its something else besides the chain... Perhaps the tensioner has failed?

**DYNOBOB** · 02-11-2011, 07:58 PM

I'm going to recommend they replace the chain, followers, and tensioner if we can get new.

It appears both cams are off by one link.

Bob

**DYNOBOB** · 02-15-2011, 07:36 PM

Well here is what I'm finding. After a lot of work the crossmember, oil pan, and front cam chain cover are off (motor is suspended from above). Once I could see all the gears it appears the marks on the sprockets all lined up w/ their corresponding marks on the block. The colored links on the chain never would line up as shown in the manual however no matter how many times I rotated. It seems that the chain has stretched to the point that the tensioner bracket was hitting the back of the tensioner and wearing away both parts (see arrows in pics). There is a lot of slop in the whole tensioner system. Since the sprockets marks all seemed to line up on the block marks it has me wondering if it did jump time. Before ordering all new tensioner parts I decided to put everything back together and recheck compression. Before putting it back together I removed some metal from the tensioner bracket so it doesn't hit the back of the tensioner thus giving the tensioner more travel to keep the chain tight. Here's what is weird, I lined up all sprockets marks and installed colored links on chain to correct marks and put back together. When I rotate the crank the colored links on the chain will never return back to the marks on the sprockets they started from. Even after 6-8 full rotations of the chain (20-30 of the crank) the closest they ever return is one link off of all three sprockets. I reinstalled chain 3 times and same results. The sprocket marks however still index to the block marks.

Any thoughts???

Tensioner connector bracket bottoming against tensioner...

Worn areas...

Area I clearanced on the bracket

**fupabox** · 02-15-2011, 09:02 PM

If you keep on turning the crank they will eventually line back up...takes a ton of rotations(same # of ratations as teeth on the crank if I remember ,but don't quote me on that)...as long as the chain remains tight the relationship between the cams and crank will not change (# of links) the chain marks are only for initial installation to make sure you have the correct # of links between each.

**greg0187** · 02-15-2011, 09:56 PM

Originally Posted by fupabox

If you keep on turning the crank they will eventually line back up...takes a ton of rotations(same # of ratations as teeth on the crank if I remember ,but don't quote me on that)...as long as the chain remains tight the relationship between the cams and crank will not change (# of links) the chain marks are only for initial installation to make sure you have the correct # of links between each.

I thought as long as the sproket marks indexed with the block it wouldn't matter? I guess like you say its just for initial installation. Now I see why willyboy had so much trouble timing his zuk. Kinda confusing...

**DYNOBOB** · 02-15-2011, 10:15 PM

Yeah, you take the valve cover off and it appears to be out of time. The repair manual just says you may have to rotate several times to line up marks.

I'll spin it tomorrow to see if they eventually line up.

**fupabox** · 02-15-2011, 11:00 PM

can't remember the method for figuring out how many rotations,but I'm sure I can google it ...something like the # of teeth per sprocket-links in the chain x the circumference of the earth on Tuesday...I'll see if I can find the true math cause now I want to know for sure as well.

**DYNOBOB** · 02-16-2011, 10:00 AM

I had not checked the valves because it seemed unlikely that all cylinders would be down on compression due to that and the cust says it was running fine all last year until Nov. Since it appears to be in time and fupa explained why the chain marks aren't lining up I decided to check the valves.

Unless I've gone retarded it appears that the valves are all tight. I cannot get any feeler gauge under any intake (not even .002). The exhaust are all 9-10 thou. Service manual says intake 7-9 thou and exhaust 12-14 thou. To measure I had the lobe totally opposite the valve...don't know how else it could be done. Sure seems weird.

Any thoughts?

Bob

**fupabox** · 02-16-2011, 11:05 AM

yeah that is odd...any oil coking on the shim surface? all being tight suggests maybe an additive was used at some time that built up a glaze on the shim buckets or surface of the shim..dribble some seafoam or kerosene on one and let it sit a while...see if it loosens a tad...maybe engine restore or some other additive that builds up with friction was used...can't see all the valves having combustion chamber deposits,but I guess that's possible as well..looks like you found the culprit though,which is good.....my only other suggestion is carbon build up in the head,but I wouldn't pull it to check until you find if the shims are glazed ..you may just need to polish them down....also you could pull all the loosest shims and put them on 1 cylinder then check compression again on that cylinder..if the compression is up than machining/replacing the shims should be the cure

**DYNOBOB** · 02-16-2011, 11:20 AM

I should have done this sooner.

Cyl 1 @ 87%
Cyl 2 @ 77%
Cyl 3 @ 61%

They match their relative compression numbers. Air escaping out the intake. Seems weird that all of them tightened up that much. I guess next move is figuring out what new shims I need. In anyone's opinion does this point to a mechanical problem other than normal seat wear? The whole inside of the motor is glazed brown but the top of shim and cam lobe are shiny. Deposits in combustion chamber or seats would cause loose not tight valves I think.

Bob

**greg0187** · 02-16-2011, 11:58 AM

Well... The valve loses its heat through the valve seat. If it doesn't seat the valve will get hot and eventually melt or burn. Could be a reason why the truck eventually got to the state it is in now. Other than that I don't have any other suggestions. Is there clearance at any point of the stroke other than TDC?