Suzuki Central Forum banner

Ltz 400 Won't start after rebuild. . Wondering what step next

5K views 33 replies 5 participants last post by  Logitechguru 
#1 ·
Hi all.

Been lurking forums for a while and have received a ton of help already. Bought a used ltz400 that I've been trying to get running. Just looking for helpful hints so I know I'm in the right direction.

Bought non running but just came back from shop having new head (big bore 434cc), new piston and rings, cam chain done. I just can't get it running now.. Here is what I've already done....

Did coolant flush and oil change
Good spark and new plug (checked stator as well and checks out fyi)
Replaced oil pump gear and checked oil pump
Cleaned carb and installed dynojet jet kit (155 main etc) I double checked this also but I'm not sure it's giving fuel for some reason as spark plug never seems real wet)
Checked valves and fixed (they were quite out.. Now within spec) and double checked again after rotating and back at tdc.
Timing is bang on.. I double checked it also
New battery

Next and only thing I can now think of is if new rebuild has busted rings and no compression (or very low) and/or carb for some reason I can't see or tell isnt working.

I'm only well versed in repairing small honda motors so this is all new to me and a bit more advanced.

Is my next step to verify compression and if it's good, replace carb?
 
See less See more
#2 ·
Check Compression to make sure nothing is off there, If that's good does it fire on ether? Try putting petcock on prime , check and make sure fuel is flowing . Check back in after these steps.
 
#4 ·
If the quad is low on compression it will not fire, I am not sure how much the compression affects fuel being sucked from the carb but I am sure it does some.
 
#8 ·
If you are sure everything is correct, the Gear could have spun on the cam, Can and does happen.
 
#9 ·
Well.. You can see by pictures I have them lined up (2 and 3 at top) with correct spacing (15 pins on chain) at tdc and they are not sitting right. That'd explain why it won't run anyway.

So.... Sounds like need new cams then?

I'd also not be able to confirm compression or anything either until proper correct?
 
#10 ·
Order a set of stage 2 Hot Cams, Priced well and will give you a little bit of power nothing crazy though. I would hold off on compression test until things are correct with the cams.
 
#12 ·
It is possible but I don't think your chain broke unless ti did and previous owner tried to fix it an dgave up.
 
#15 ·
It seems like you have some knowledge, I just rebuilt mine, I used Wiesco Valves and replaced the seals and guides, I would get a new Chain as well.
 
#16 ·
Took valves out and yup... They are bent.

So.. I'll order some new ones. If I get stage 2 Ames, I need drz springs? And I keep reading not to lap valves so how do I clean up seats with new valves?

Also, how can I tell if my guides are good or not? I've searched a fair bit on replacing valves but I can't seem to get good info on seat prep or how to check/change guides
 
#17 ·
Honestly i am not sure how to explain it, but its not a bad job, The DRZ springs should be used if getting a higher reving CDI Box, but I would recommend doing them while you have it a part either way, I think everyone is going to have their oppion on what brand to run, I honestly think you will be fine with Wiesco, Ferrea or KW. Is the piston ok? You could check ring end gap while you are in there and replace if needed, I would use DRZE gasket while its apart and probably replace teh Chain guides as well. I just did my sons and replaced everything.
 
  • Like
Reactions: Sidingking
#18 ·
Ok so ordered hot cams stage 2 and full set of kibblewhite valves and springs etc. And yes...my wife wants to kill me.

My question (and hard to find an answer it seems) is how do I know if my valve seats are good? They 'look' okay (I just wiped them clean etc)

Since I can't use compound on the new titanium valves and my old ones are bent, what's the best method to get a good seal and how to I check seats?
 
#29 ·
Ok so ordered hot cams stage 2 and full set of kibblewhite valves and springs etc. And yes...my wife wants to kill me.

My question (and hard to find an answer it seems) is how do I know if my valve seats are good? They 'look' okay (I just wiped them clean etc)

Since I can't use compound on the new titanium valves and my old ones are bent, what's the best method to get a good seal and how to I check seats?
You'll know if the seat or not lol I didn't do mine yet but I did my yfm100 last year and was able to tell they sat
 
#19 ·
I am going to have to let someone else see if they can guide/explain it to you. I am going to assume you will probably be fine , I did replace mine but I don't believe it was really needed. Make sure you do the timing chain and guides as well.
 
#20 ·
The only way to know for sure if your seats are good is the have them cut, or do a light lap, which is dubious with those valves. Or you could ignore it, and try gas in the chamber, see if leaks past the valves. You could buy 2 new wiseco valves and use those to lap the seats as well.
 
#23 ·
I'll prob ask if local shop has an old one I can use to lap if it needs it. Can't see me buying a wiseco to toss out since it'd cost me like $60 cad before shipping even
Where are you located?
 
#22 ·
Id clean up best you can I think you'll be fine.
 
#25 ·
I'm 2 hours East of TO. I should have old valves, but not sure I could find them anyway.
 
#26 ·
Ya.. Picton is a bit of a drive 🙂

I'm just going to see how they seal with new valves, springs etc I have coming. If they are terrible and leak a lot, I'll bring it to local bike shop and see if they can give me a hand. Nice thing about being small town area... Local small shops usually pretty good to assist for a case of beer
 
#27 ·
Hi all.

Been lurking forums for a while and have received a ton of help already. Bought a used ltz400 that I've been trying to get running. Just looking for helpful hints so I know I'm in the right direction.

Bought non running but just came back from shop having new head (big bore 434cc), new piston and rings, cam chain done. I just can't get it running now.. Here is what I've already done....

Did coolant flush and oil change
Good spark and new plug (checked stator as well and checks out fyi)
Replaced oil pump gear and checked oil pump
Cleaned carb and installed dynojet jet kit (155 main etc) I double checked this also but I'm not sure it's giving fuel for some reason as spark plug never seems real wet)
Checked valves and fixed (they were quite out.. Now within spec) and double checked again after rotating and back at tdc.
Timing is bang on.. I double checked it also
New battery

Next and only thing I can now think of is if new rebuild has busted rings and no compression (or very low) and/or carb for some reason I can't see or tell isnt working.

I'm only well versed in repairing small honda motors so this is all new to me and a bit more advanced.

Is my next step to verify compression and if it's good, replace carb?
CHeck the timing. . 10 and 2 I believe. My hotcams are new style and and are slightly off. But that's how they are to be
 
#28 ·
Hi all.

Been lurking forums for a while and have received a ton of help already. Bought a used ltz400 that I've been trying to get running. Just looking for helpful hints so I know I'm in the right direction.

Bought non running but just came back from shop having new head (big bore 434cc), new piston and rings, cam chain done. I just can't get it running now.. Here is what I've already done....

Did coolant flush and oil change
Good spark and new plug (checked stator as well and checks out fyi)
Replaced oil pump gear and checked oil pump
Cleaned carb and installed dynojet jet kit (155 main etc) I double checked this also but I'm not sure it's giving fuel for some reason as spark plug never seems real wet)
Checked valves and fixed (they were quite out.. Now within spec) and double checked again after rotating and back at tdc.
Timing is bang on.. I double checked it also
New battery

Next and only thing I can now think of is if new rebuild has busted rings and no compression (or very low) and/or carb for some reason I can't see or tell isnt working.

I'm only well versed in repairing small honda motors so this is all new to me and a bit more advanced.

Is my next step to verify compression and if it's good, replace carb?
10 to 1 its the timing. . Maybe they didn't put it back togather the correct way after bbk. I have stage 1 hotcams and athena 440 I put In mine. Just got the fcr mx carb from keihin and man it is bad a$$ . Carb will factor over it all
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top