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FRZ 400 Mechanic
- Thread starter nigel
- Start date
Interesting. That wouldn't be my first guess on cause for a hard start (or even in my top few guesses), but if that is what other people have been discovering I will keep it in mind when I have something that is acting up in the future.
@Brian P thoughts?
Psycho_Biker
Well-known member
Is it an EXUP equipped bike? Does it have the stock exhaust?
You can find videos on youtube and some old guides on Yamaha forums for the valve clearances.
You can find videos on youtube and some old guides on Yamaha forums for the valve clearances.
fugue
Well-known member
Hard start is indeed a symptom of tight valves, but there could be other reasons, too.
OP doesn't sound too mechanically inclined - a mechanic is his best bet. Shim under bucket valve adjustment isn't something for a noob to start with.
Don't know where you're located, but I'll suggest Pro6 for a shop that has seen that kind of bike before. They should be able to help you.
Edit: And, no it's not an old bike, and many parts are still available (except things like crankshafts and pistons) from Yamaha.
OP doesn't sound too mechanically inclined - a mechanic is his best bet. Shim under bucket valve adjustment isn't something for a noob to start with.
Don't know where you're located, but I'll suggest Pro6 for a shop that has seen that kind of bike before. They should be able to help you.
Edit: And, no it's not an old bike, and many parts are still available (except things like crankshafts and pistons) from Yamaha.
I know those bikes very well, I have two of them and one of them was my race bike for 23 years. But, at this time of year, time is not in abundant supply. I've got plenty of my own stuff to take care of without having to think about anyone else's stuff.
Hard starting when cold ... These bikes are really finicky about their carburetors at the best of times. If fuel was left in the bike over the winter, it is not going to be happy about it now. Was the bike like this last year, or is it just now that it's like this?
They benefit from one size richer pilot jets. They benefit from iridium spark plugs (CR9EIA-9 extended tip - the extended tip won't collide with the piston if it has stock pistons in it). The stock charging system is not good; if the battery is not up to snuff, it won't crank fast enough to start. I've got a pile of stock voltage regulators, most of them fried (mine now have modern regulators and lithium batteries). The valve clearances do indeed need to be spot-on. If the engine is tired, that won't help.
The rubber adapters from the airbox to the carbs harden up over time. If you take the airbox off (necessary for working on just about anything on these bikes), and those boots have hardened up, they will never seal again. I don't know if you can still get new ones. I've gone through a few sets of those. Usually this doesn't affect starting and idle, but it will make it lose power and stumble and miss under load.
Options:
Pro 6 Cycle might be an option. Both Craig and Mark are mechanics who date back to when those bikes were current.
HB Cycle might be an option. The owner, Phil Hodgson, is a major supporter of the VRRA (Vintage Road Racing Association) and he supports a few FZR-riding competitors.
Blackstock Cycle might be an option but I don't know anyone there. They support Kirby Crosby, another FZR-riding VRRA competitor.
Contrary to someone else's suggestion above, parts availability for these bikes is dwindling fast, and is largely behind my decision to retire my FZR race bike and start over with a new (almost) bike. (I built an R3 for this year.) My FZR can stay right where it is, in front of a wall of trophies.
Hard starting when cold ... These bikes are really finicky about their carburetors at the best of times. If fuel was left in the bike over the winter, it is not going to be happy about it now. Was the bike like this last year, or is it just now that it's like this?
They benefit from one size richer pilot jets. They benefit from iridium spark plugs (CR9EIA-9 extended tip - the extended tip won't collide with the piston if it has stock pistons in it). The stock charging system is not good; if the battery is not up to snuff, it won't crank fast enough to start. I've got a pile of stock voltage regulators, most of them fried (mine now have modern regulators and lithium batteries). The valve clearances do indeed need to be spot-on. If the engine is tired, that won't help.
The rubber adapters from the airbox to the carbs harden up over time. If you take the airbox off (necessary for working on just about anything on these bikes), and those boots have hardened up, they will never seal again. I don't know if you can still get new ones. I've gone through a few sets of those. Usually this doesn't affect starting and idle, but it will make it lose power and stumble and miss under load.
Options:
Pro 6 Cycle might be an option. Both Craig and Mark are mechanics who date back to when those bikes were current.
HB Cycle might be an option. The owner, Phil Hodgson, is a major supporter of the VRRA (Vintage Road Racing Association) and he supports a few FZR-riding competitors.
Blackstock Cycle might be an option but I don't know anyone there. They support Kirby Crosby, another FZR-riding VRRA competitor.
Contrary to someone else's suggestion above, parts availability for these bikes is dwindling fast, and is largely behind my decision to retire my FZR race bike and start over with a new (almost) bike. (I built an R3 for this year.) My FZR can stay right where it is, in front of a wall of trophies.
nigel
Member
Thanks for all the details, had I known the group would be this helpful I would have provided more info. The bike has been stored in a garage for the last 3 years. I have owned the bike for 10 years and it has 75,000 kms on it. Previously when I rode, it was always hard to start on cold days. I removed the carbs and cleaned them and surprisingly they were not that bad at all. I changed the voltage regulator a few years ago when the original one died. I put new spark plugs and I was boosting it when I attempted to start it. I did get it started once and it idled fine after a few minutes. Trying to start it the next day and it wouldn't fire up, even with boosting it. I have never adjusted the valves and I got the bike with about 35,000 kms so my guess is that they need doing. I am debating if I can do this myself or not. I have done it on VWs and my dad is a retired auto mechanic but not too sure if we know enough to make it better or worse! It seems like a very tight area to work, can it be done with the engine in the bike or do you need to remove it to get proper access. Thanks again for the information.
FZR400 winter overhaul
Post 70 discusses valve clearance.
Post 70 discusses valve clearance.
Trials
Well-known member
Riceburner
Well-known member
Last edited:
Trials
Well-known member
True that, but if you want to hear rare, I have a Spanish motorcycle that I bought new in 1976 and they built less then 400 units of that model :| imagine finding parts for it.
The nice people at Yamaha Canada once told me they try to keep major replacement parts for bikes ~ 7 years post production fwiw
That bike went out in 1994 so ya, that one is going to draw a blank at Canadian parts counters.
fugue
Well-known member
Sounds like you have a chance at it then. Get a service manual. It goes over the details of valve inspection and adjustment quite thoroughly - I wouldn't attempt the job without it. It can be done with the motor in the bike, but its a bit tricky - far easier with the motor out. Depends how far you want to go with it. Do an inspection and see where you stand. Check your battery and charging system again though. It could also be the starter - if its worn out it might not crank fast enough to fire the bike, despite everything else being right.
Brian is correct, parts are disappearing quick, but the common stuff and consumables can be had as many were shared with other bikes. Carb/airbox boots may now be among the missing. So don't cock up the valve adjustment!
Psycho_Biker
Well-known member
How old is your battery? If it was connected to the bike for a while or if it's more than 3 years old and was sitting without a battery tender that thing is done.
nigel
Member
The battery is old so I did boost it with another one and even tried with a booster pack. The starter seems to turn over pretty good but I don’t really have a reference point as to what a good starter should sound like when cranking. My plan is to check the compression and then valve clearance. Then I’ll have to decide how much I want to invest in the bike. It is such a classic I really would like to keep it.
My standard approach for hard to start vehicles from storage where i can get access to the air intake is an unlit propane torch on high (or maybe two for the 400) up he snoot of the air intake. The engine fires on the propane and a few seconds of vibration and heat is enough to get gasoline flowing so you can pull the torches.
Obviously if it is hard to start even after its been run some, a proper repair should be investigated.
Obviously if it is hard to start even after its been run some, a proper repair should be investigated.
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